Session of the week #6: 1 on:1 off – a balanced first introduction to structured training 

Original article and downloadable session available here.

Do if… you want to start including intervals into your rides for fitness gains

Ready to get fit through cycling? This cycling workout is great for both those first dipping their toes into structured training, as well as seasoned athletes looking to build up their fitness again after a long time off the bike for whatever reason. 

For everybody, there is the temptation to jump straight in with the most brutal workout you can find – start as you mean to go on, right? But really, that just spells a one-way ticket to common cycling injuries, ironically leaving you with more time off the bike. 

This cycling workout will get you working, expanding good levels of energy and stimulating those signals which tell your body that these muscles are being used. At the same time, this workout isn’t so intense as to risk any strains, here we’re building the foundations of fitness in the right order.

So, what’s in store? We’ll be starting off with a 10 minute warm-up followed by five one-minute efforts at threshold, each followed by one-minute really easy pedalling. After that first ‘block’, it’ll be five more minutes of recovery and then repeating that one-minute ‘on’ / one-minute ‘off’ block.

You should feel your legs working in the efforts, but it shouldn’t be anything like an all-out sprint for the line. Think about the kind of intensity you’d be putting in when cycling into a hard headwind or up a long – but only moderately steep – hill.

For those using and training with a power meter or heart rate monitor and who know their training zones, you’ll know what constitutes a Threshold – or Z4 – effort. But you can just plug your FTP or Critical Power (CP) into this session and it’ll work out all the numbers for you. 

But be warned: if you are coming back from a long time off, your numbers are likely going to be very different to what they were. And jumping straight in with an FTP test as your first time on the bike isn’t a particularly pleasant way to get going – best build yourself up training on feel just initially. 


For those of us who have just started riding, all these numbers and power thresholds can be quite daunting. If you have acquired a power meter, you might not have done a power test yet, or even know how to! Although it is beneficial to have done a power test before doing these sorts of efforts, they can still be done using the power that you know you can maintain for a local 10 mile time trial. If you haven’t done one of those, you can do this cycling workout at the power that you can maintain for a 10 minute climb, with a reduction of 10 to 20 per cent.

For those without a power meter, you can use heart rate but, to make sure that the efforts are consistent, you can track your average heart rate during each minute and try and keep this the same. Your heart rate will increase during the efforts but you want to make sure you are not hitting your max heart rate. Essentially, you are looking for each effort to be around the same average heart rate and also the same peak heart rate.

For those without a power meter or heart rate monitor, you can do this based on RPE. It can be a bit difficult to gauge what the effort feels like as this effort sustained for 20 minutes will feel a lot harder than sustained for one minute. A good rule of thumb would be that each one minute interval feels like a seven out of 10. So, it is a hard effort, but one that feels like it would be easily sustainable for longer than the one minute.

The benefits to this cycling workout are various. It does produce a training stimulus due to having to start the effort, have a short break, and then start another effort – a bit like doing micro intervals but on a slightly larger scale. You can read more about some of this benefits in the explainer to a 20/40s cycling workout. For the most part though, the session presents a good opportunity for people to begin adding intervals and structure into their training.


Don’t start the first effort too hard or, by the time you get to the later effort, it will feel too difficult. Pacing can be a tricky thing to learn in the early stages and it might be that the first few times you do the session, you do the first couple of efforts too hard. However, the more familiar you become with judging your own internal sensations whilst riding, the better you will get at pacing your efforts without using either heart rate or power. 


For riding outdoors, this cycling workout requires a little thoughtful planning as it involves quite a long period of alternating focused effort and rest. There are several ways to approach this. The first is to find a 10 minute section of flat or rolling road that doesn’t have any disruptions like tight corners, junctions or traffic lights. You can do your one minute of threshold and then your one minute of rest easily as, on the flats, you can rest properly. You then need to repeat this five times in total to do one effort block. The rest between effort blocks can be extended slightly to suit your needs.

The other way of doing the cycling workout is to do it on a climb that is 10 minutes long. This can be a bit more difficult as the rest period is going to be harder because you will need to push out more power on the climb than you would on the flats. However, it is still possible to complete the workout this way.

Session of the week #5: Under/Overs – improve your ability to recover while still pushing the pace [59 mins]

Original article and downloadable session available here.

Do if… you want to improve your threshold power and your capacity to recover at higher intensities

The goal of this cycling workout is not only to help us perform at intensities above Crticial Power, but also to aid recovery from high intensity efforts. For example, if you’ve pushed hard on a steeper section of a climb and then want to recover on a flatter section whilst still keeping some intensity. The benefits of this workout could be valuable either in a race situation or on any climb you’re looking to improve your time on.

What’s coming up? So this week’s cycling workout involves a longer warm up of 15 minutes followed by a block of one minute at 110/120 per cent of Critical Power (CP), then two minutes at 95 per cent of CP, times four (12 minute total block). 10 minutes recovery, then repeat the ‘under/over’ block, with a 10 minute cool down to finish off.

Critical Power is an alternative to FTP for setting training zones, find out how to get your numbers and use them in our explainer on Critical Power here.


When we do hard efforts, we need some time to recover from them. But if we’re riding up a long climb or during a race, sometimes we have to try and recover at a pace that itself is still quite high.

Riding at 110-120 per cent of CP is a hard effort and, for a lot of people, is in their Maximal Aerobic Power (MAP) range, so is not sustainable for long as it will drain our Watts Prime (W’) – more information on this metric and how it’s beneficial for training can be found in our explainer on Critical Power here as the two metrics go hand in hand.

To counter this, the effort will only be for one minute before we dip just below CP. Even though this is still a hard effort, it does allow us to recharge our W’ sufficiently so that we can complete several more of these ‘under/over’ efforts.

The reason we have a range of 110 to 120 per cent of CP is that, for different individuals, their W’ in relation to their CP may be smaller – or their MAP might be a lower percentage of their CP.

Doing these sorts of efforts not only gives us a training stimulus to improve our CP or sustainable threshold power – it also helps us to recover at higher intensities where heart rate (HR) remains elevated and likely will not drop much.


So, let’s take a rider with a CP of 300 watts (W) and a W’ of 15000 joules (J). They’ll be doing one minute at 360 W (120 per cent CP) leaving their W’ at 11400 J. Then, after two minutes at 285 W (95 per cent CP), their W’ is recharged to 13200 J. Theoretically, using this model (which is referred to as W’bal) means that, during effort eight, the rider empties their W’ and is unable to complete it. However, factors such as heat, pain resistance – and anything else that contributes to fatigue – mean that failure to complete an effort often occurs earlier than predicted.

During the ‘over’ section, our HR will be significantly elevated and, although it can decrease slightly during the ‘under’ section, it still remains quite high compared to the level we’d normally be accustomed to during the recovery period. Quite often, this results in us hitting a plateau and reaching our VO2max – the point at which our oxygen consumption is at its maximal level. So, not only can these sessions help with maintaining high power for extended periods and recovery at high intensities, but they can also assist in improving our maximal capacity aerobic performance.


Don’t overdo it too soon. It can be easy to get carried away with the first few ‘overs’, which will lead to either having to decrease the power for the other ‘overs’ or decrease it during the ‘unders’, both of which defeat the purpose of the session. 

After the first block, if it felt a bit easy at say 110-115 per cent CP, then increase to 120 per cent for the next block. 


These sessions can be done outdoors but, because the effort blocks are a bit longer, it is very important to find either a good uninterrupted stretch of undulating road with minimal potential for possible disruptions, or a 12 to 15 minute climb. 

A local time trial course often provides a good bit of road to complete the efforts on but, for a lot of people, a longer climb may present a slightly easier way to hit the power targets as the positive gradient provides consistent resistance. However, the ability to put high power down on the flats is very important, especially for time triallists and other racers, so mixing up the terrain you complete this cycling workout on is also advisable.

Session of the week #4: Rev outs – spin your way to quick wins [1hr]

Original article and downloadable session available here.

Do if… you want to maximise on the fitness you already have and develop your pedalling efficiency

Most of us riding a bike want to get faster, be it for racing, making your way up the Strava KOM leaderboard, or increasing the average speed of your ride. Improving pedalling efficiency is a great way to achieve this, but is often an area of training which gets neglected and is seldom given enough specific focus. 

This week’s cycling workout targets pedalling efficiency with six 15-second efforts where the goal is to spin your legs as fast as possible with about eight minutes rest between each effort.


When we pedal, we are producing power. To go faster, we need to produce more power, physiologically speaking anyway. Power itself is made up of two elements: torque and angular velocity. The torque is the force that we apply (think about a torque wrench – the higher the torque the more force you are applying to that poor seat-clamp). 

The angular velocity is the speed at which that torque is applied – in other words, your revolutions per minute (RPM). If we are able to increase our speed (angular velocity) whilst maintaining the same torque, we can produce more power. 

This session essentially helps you be able to turn your legs at a faster speed and is beneficial as a lot of people ride at a cadence that might not be most efficient for them.


So, how does this session help you do that? Well, when we pedal, we experience something called muscle coactivation. This occurs when you push down on the pedals with your quads (the agonist muscle group), yet you experience resistance from the hamstrings (the antagonist muscle group). 

This happens for several reasons, but is predominantly because the hamstrings are trying to help stabilise the knee. So, when you push 100 watts down, you may also be encountering 10 watts negative force, resulting in a net forward positive power output contributing to forward momentum of 90 watts. 

Several studies have investigated this in depth and found that well-trained professional riders experience far less hamstring muscle activation during the downstroke of the pedal phase than amateurs who train less, therefore producing a higher positive power output. So, in our 100 watts example, minus 10 w reduces to minus 3 w (not exact relative figures). 

Doing these high cadence drills (where novice riders may struggle with 100+ RPM and experienced riders can push north of 200!) can help in reducing this muscle coactivation.


Don’t worry about bouncing on the saddle. These efforts feel very alien to conduct and quite often, as you reach a higher RPM, it feels uncomfortable and you bounce up and down on the saddle as the muscles try to fire in the right pattern at a high speed. This is normal and will reduce as you get used to these efforts and develop a more efficient pedal stroke. 


These efforts are very easy to do outside: find a nice, flat stretch of road. Starting at a ‘walking’ pace, select your smallest gear. Then, as the title suggests, rev out! Pedal as fast as you possibly can for 10 to 15 seconds. The rest periods between the efforts can be longer or shorter, depending on the overall ride that you are doing as the physiological effort of rev outs is low, therefore recovery is quick. 

Session of the week #3: MAP (Maximal Aerobic Power) efforts – Boost your speed on steep climbs [1hr 5 mins]

Original article and downloadable session available here.

Do if…you want to build your maximal aerobic engine to stay with your mates on four to six minute climbs

Do you find yourself getting dropped as soon as your mates decide to blast it up a short climb? You’d have them on a mountain or longer hill – but sadly, that’s terrain you’re blessed with…

If this hits close to home – or if these efforts are already your happy hunting ground and you wish to further improve – then this week’s session is ripe for you.

The purpose of this cycling workout is to stress our maximal aerobic system and improve not only our aerobic capacity but also our ability to produce large amounts of power for intervals of between four to six minutes. 

These are especially useful for those looking to be stronger on climbs of this duration, which are very common in the UK. Plus, if you’re interested in racing, this cycling workout also helps with improving pursuit efforts.

After you’ve warmed up, there’s four sets of four minute efforts at 110-120 per cent of your FTP (or Critical Power) with six minutes rest. 

Critical Power is an alternative to FTP for setting training zones, find out how to get your numbers and use them in our explainer on Critical Power here.

These four minute efforts are not far off your five minute maximum power which is often referred to as Maximal Aerobic Power (MAP) – so they are going to feel tough. Just make sure you have enough left in the tank so that you can still hit the same numbers on the last interval as the first.


The way this cycling workout works can be treated as quite straightforward: you want to improve your four to six minute efforts – so pop some four minute efforts into your training.

It’s important to note that these efforts are on the shorter end and also aren’t quite at the very limit of your physical capacity. Going too hard and long at the start of the session would impact the later intervals – what you really don’t want to do is exhaust yourself so you end up putting out too little power by the end. 

The goal is to stress the aerobic system – and that does require some level of pacing.


The range of power for these efforts varies significantly, depending on your power profile as a rider. Often, a rider’s maximal aerobic power will fall between 110-120 per cent of FTP (or Critical Power) but, in some circumstances, it can be higher or lower. It is referred to as MAP, as efforts shorter than this are more glycolytic and have a higher percentage of anaerobic contribution, hence why MAP is defined as being the maximal power efforts we can sustain predominantly aerobically. 

What we (as coaches or athletes) are looking for in these efforts is two-fold. The first objective is maintaining a higher power for the duration. This is useful for Individual Pursuits (IP), where a high but steady maximal power is required for 4 to 4.5 minutes. For targeting IPs, doing these efforts in the aerodynamic position will help to maximise power in that position. 

Sustaining power in this way is also extremely useful for improving your time up a local climb during a road ride, and competing in road races or hill climbs, where four to six minute climbs are a common occurrence. In road races, these climbs often present a great opportunity to break away, drop the opposition, or are the location of the finishing line. So, being powerful over this duration is very important.

The second metric we want to monitor is the Heart Rate (HR) response to the efforts. These are sometimes referred to as VO2 max efforts as, during VO2 max Ramp tests, MAP is often the power at which VO2 max is achieved. However, VO2 max is not a power output, and can be achieved by different methods. 

VO2 max is defined as: the maximal rate of oxygen consumption where HR is maximal (or near maximal) and rate of perceived exertion is 10/10 (or 20/20 on the Borg Scale). One way of determining if VO2 max has been achieved is by looking for a HR plateau. Essentially, the HR hits a maximum, but does not increase any further as maximal oxygen uptake has been achieved. Improving VO2 max is the key to improving aerobic performance.


Don’t worry about maintaining the power for the efforts in this cycling workout; the main focus is getting the HR up so starting closer to 120 per cent of Critical Power, and even dropping to 105 per cent, is not an issue. If IP is a goal then maybe try to average as high a power as possible with an initial surge followed by settling into the effort whilst aiming to achieve limited drop in power by the end of the interval.  


These efforts are fairly straightforward to conduct on the road. For IP, it is best to do these efforts on a time trial bike so you can work on producing power in the aerodynamic position. In this case, find a nice flat or rolling stretch of road that lasts for more than the length of the effort. 

It requires a bit of route planning, or repeats on the same stretch of road, but it is manageable. Don’t worry too much about the time between efforts, just make sure you are recovered for each one and able to push your hardest.

Another simple way of performing these outside is by locating a four to six minute climb. Once you have completed your four min effort, you can recover by either turning around, riding on the flat or continuing to the next climb before repeating your effort. If you need to continue to the top of a longer climb, have a longer rest between efforts as you will likely be riding at a higher intensity than recovery up the rest of the climb.

Session of the week #2: Glycolytic Capacity Efforts – Short hills? Long sprints? Same session. [1hr 3 mins]

Written for Cycling Weekly, you can download the training session here

Do if… you love short, sharp and steep hills (–or if they’re your nemesis), plus it’s also good training for long, drawn-out sprints.

Although the efforts in this cycling workout are only very short – at just one minute long – these will feel very hard and near maximal. Be prepared to dig deep, but don’t be tempted to go too hard early on as you’ll want to still be able to maintain the same output in the last interval. 

This is a particularly useful cycling workout for those targeting shorter hill climb events where glycolytic muscle fibres will be the primary source of power. And also for longer efforts, such as at the end of a road race, where you want to catch everyone off guard a bit and go for that long drawn out sprint effort. 

Even if you don’t have any target events, this is still a nicely tough HIIT cycling workout for a quick and efficient fitness boost. 

This cycling workout starts with a long warm up, and is followed by 4 x 1 minute “very hard” efforts with six minutes rest. 


The muscle fibres you use in high intensity efforts are actually distinct to the ones used in endurance efforts – so you could potentially be doing hours of training but leaving this whole area completely neglected. 

These one minute efforts will activate that energy system, helping to improve your climbing, more specifically your ability to blast up short, sharp and steep hills. It’ll also boost the amount of power – and duration – you can sustain for a long, drawn-out sprint. Great for catching people off-guard in a road race or blasting your way up the pack in a Zwift race at 500m to go.


Efforts such as those in this cycling workout are referred to as glycolytic efforts because of the way in which we produce power at these intensities. This happens when we break down glucose into lactate without using oxygen (anaerobically) and, although it doesn’t produce as much ATP (Adenosine Triphosphate, which our body uses as energy for every action), it produces it far more quickly than breaking down fats or carbohydrates aerobically. 

The type of muscle that produces power this way is also different. When we do low intensity and primarily aerobic efforts, we use Type 1 muscle fibres (Slow Oxidative), whereas glycolytic efforts use Type 2A and 2B fibres (Fast Oxidative and Fast Glycolytic). These Type 2 fibres have more ATPase (the group of enzymes that hydrolyse ATP) and therefore produce muscle contractions far quicker than Type 1 fibres, allowing for faster and more explosive movements. 

In other words, you can reach maximal tension more quickly therefore producing a higher power, power being a combination of the force and the speed at which force is produced. 

So, how does this cycling workout help? Well, as with all training, we adapt to the stress we present the body with. In this case, we present the body with a highly glycolytic effort which requires ATP very quickly to produce high power. When we do these types of efforts, the training response from the body is to increase the amount of glycolytic enzymes and ATPase in the muscle fibres, thus increasing the rate of energy production and our capacity to produce these high-powered efforts.


Stick to the power numbers as best as possible; you don’t want to go too hard to start with and then find that you can’t produce the power by the end of the effort or find yourself weakened for the final effort. Your muscles will fatigue quickly so it’s important to go very easy between the efforts in this cycling workout.   


For conducting the efforts in this cycling workout on the road, hill reps are an ideal way to do this. Find a hill that you know takes you a minute or longer to get to the top of and do your efforts up there. Once you’ve done the minute interval, return to the bottom of the hill and spin easy for the six minutes recovery before the next effort. 

Don’t worry too much if there is a longer rest period between the efforts, or a longer warm up or cool down is needed to get to and from an appropriate hill.

These efforts can be done seated or out of the saddle, and you can play around a bit with the cadence depending on what feels most suitable for you. The key here is getting one minute at a high enough power to elicit the training stress that we are looking for.

Stay tuned for next week’s session, we’ll be bringing you a fresh new cycling workout every Monday. 

In the meantime you can find more indoor cycling sessions for turbo training here, sessions specifically if you only have 30 minutes spare to work out here, and training plans for beginners, intermediates and racershere.

Or how about having a go at one of the previous cycling workouts of the week:

 – Cycling workout of the week #1: 20/40s [50 mins]

Warm weather riding tips

Cyclists are often sun seekers, it’s a chance to get out and do long rides without the danger of rain or having to meticulously re-clean our bikes and drivetrains. It’s also the perfect opportunity to strengthen up that cyclists tan! However there are some things that you should do when riding in warm weather to ensure performance is not effected and that you don’t harm yourself. So, here are a few tips for warm weather riding:

1 – Sun cream! Sweat resistant sun cream is an essential, and if possible bring a small one with you on longer rides. Be sure to get your arms and legs, but don’t forget about face, back of neck, and ears which are common places that catch the sun. Although you may not get sunburn, or even feel you’ve caught the sun at all, damage will still be occurring to the skin which can lead to things like skin cancer further down the line. Always better to use sun cream than not when the sun is out! And don’t worry, you’ll still tan with sun cream on!

2 – Don’t overdo it. Especially when there are sudden changes of temperature (say from mid 20 degrees to high 30s!) and when this happens it is unlikely that we will be at all adapted to the heat. This makes it very important to not overdo it on these days as heat stroke and exhaustion can leave you feeling very tired for a few days.

3 – Hydration. It’s not just about drinking water, you need to include salts. Dehydration will tire you, but consuming too much water without enough salts can lead to a dangerous thing called hyponatraemia (low sodium). To avoid this, aim for 0.5g of salt per 500ml bottle if you sweat a lot or are a salty sweater. Just electrolyte tablets by themselves don’t often include enough salt. Still aim for at least 500ml fluid/hour. You can check sweat rate roughly by weighing yourself without clothes before a ride, doing a ride on the turbo for 30min, and weighing yourself after. Initial weight minus weight after, plus any fluid consumed, is your sweat rate. This can change with adaptation to heat and also exercise intensity, but gives a general idea. As for salt levels of sweat, that’s more difficult to measure. But if you leave salt patches on your dark jerseys after a shorter ride in the heat, you probably are a salty sweater.

4 – Fuelling! In the heat, we use more carbohydrates, so be sure to bring extra carb sources for that on the bike fuelling. If doing longer rides or high intensity, aim for ~60grams/hour in food or drink form.

5 – Heart Rate (HR). For those that use HR to gauge their training zones, be aware that in the heat your heart rate will likely increase relative to power. So at 200 watts, 120 BPM may now be 130 BPM. Also greater cardiac drift is a common thing to see when training in very hot weather. So if you start the ride at 200 watts and 130 BPM, you might finish it >140 BPM.

6 – Take a break. If you really feel the heat getting to you, find some shade, eat and drink, and get going when you’ve cooled down a bit. Although you ideally don’t want to interrupt your endurance training rides, if the heat gets too much for you then it is vital to give your body a chance to cool down.

7 – Ride early. The sun is at its highest come midday, but the temperature continues to rise beyond then. Best to get out earlier in the day and have your ride done and dusted before it gets even hotter. Or given it’s a red weather warning, train indoors or take rest day and stay cool. You could do more harm than good if you push it.

Session of the week #1: 20/40s – Just how hard can 20 sec intervals be? [50 mins]

Do if… you’re looking to boost your high-end power – whether that’s for races, Strava segments or as a HIIT-style workout

(Link to original article on Cycling Weekly)

This is a classic cycling training session used by many coaches for riders doing events such as criteriums, track races, or road races where the effort level required changes frequently due to changes in pace of the bunch, attacks, and sprinting out of corners.

It consists of a 10 minute progressive warm up, 10 x 20 second hard efforts, followed by 40 seconds of easy recovery. Then, a 10 minute rest before repeating the first block again. Finally a 10 minute cool down.

These intervals can be fitted into an indoor cycling session less than an hour long so are quite manageable to fit into even a busy schedule with limited training time.

Due to the high intensity nature of the 20 second efforts, your heart rate response from these efforts for the 10 minute block will be more like a sweetspot or sub-threshold effort – even with those 40 seconds of rest. For some, this is easier than doing a solid 10 minutes of threshold. 


The main benefits of this session is that it will help to increase the amount of power you can put out over your threshold, helping you improve your climbing on punchy ascents and following attacks in races. It’ll also increase your repeatability of these efforts, helping you stay up there hill after hill and corner after corner.


Another way of explaining why these intervals are so good for events like Crits is that they help improve your ‘Watts Prime (W’)’. This is the amount of energy above Critical Power (CP) that we can use and recharge. Basically if ‘W’ is a battery, then these efforts can help increase the size of that battery. Critical Power is an alternative to FTP for setting training zones, find out how to get your numbers and use them in our explainer on Critical Power here.

They also help with building resistance to fatigue generated by inorganic phosphate (Pi) production. This occurs with changes of pace from an easy intensity to a harder one. As the initial increase of power uses the phosphocreatine (PCr) pathway to produce energy quickly, your aerobic and anaerobic pathways will then be providing the rest of the energy. 

The issue is that using the PCr pathway leaves metabolites – in this case Pi – which can affect muscle contractile function, and therefore our ability to contract the muscles and produce power. But by training like this we can increase our capacity to remove Pi and thus experience less fatigue.

Additionally, active recovery (easy spinning) has been found to be better at removing Pi from the muscles and resynthesise it into phosphocreatine than no pedalling at all. So a way to make this session harder would be no pedalling in the 40 seconds rest.


The 20 second efforts shouldn’t be performed maximally from the start. If you do that, then about halfway through the 10 minute block you will start to really feel it and regret it. Your power will also start dropping off and you won’t gain the full benefits of the session.

Consistency is key. So stick to the prescribed effort level of 140 to 150 per cent of Critical Power and the intervals will feel steadily harder as the session goes on.

Another thing will be getting in the right gear for the efforts. In ERG mode this is easily done, but if performing the session in Level mode or outdoors, then gear selection is key. Choose one that you can start pedalling at, perhaps this is a cadence around 80 RPM, and then increase as the effort continues.


With the blocks being only 10 minutes long, these can be done quite easily outside in most places. Ideally you want a stretch of road that is flat or undulating, minimal tight corners, and no junctions. 

These can be done uphill, but bear in mind that recovery will likely be at a higher power output due to being on a climb so will make the session harder and maybe limit power output during the 20 second efforts. 

As with any outdoor efforts, it is good to know the stretch of road well so you are aware of any hazards such as potholes or gravelly corners. For riding outdoors, you can also increase the duration of the warm up and cool down around the efforts, as well as the 10 minutes easy riding in-between blocks. The key thing is getting the 10 minute blocks of 20/40s done spot on.

Stay tuned for next week’s session, we’ll be bringing you a fresh new workout every Monday. 

In the meantime you can find more indoor cycling sessions for turbo training here, sessions specifically if you only have 30 minutes spare to work out here, and training plans for beginners, intermediates and racers here.

Should we forget about FTP and just use Critical Power for training?

Written for, and first published, on Cycling Weekly

Critical Power tests are easier to do and you get a clearer picture of your fitness profile – there’s little not to like 

In recent years, the main metric for measuring performance and gauging progress has been Functional Threshold Power (FTP) – often ascertained by either a 60 minute maximal test or 20 minutes with the result multiplied by 0.95. 

More recently, though, other metrics – such as Critical Power (CP) and Watts Prime (W’) – have risen to prominence. Being more informative and encompassing than FTP, those who train with these CP and W’ can be more targeted and better assess their performance.

Plus, with the increasing availability of cheaper power meters and smart turbo trainers, training with power is something that’s open to a lot more of us. 

We’ll take you through what Critical Power (CP) and Watts Prime (W’) actually mean, how to find your numbers, and – once you have your values – how this knowledge can be used for more targeted training and a performance boost. 


Critical Power (CP) is essentially the power that you could theoretically maintain indefinitely, being the point at which an effort goes from being aerobic to anaerobic. Put another way, it’s when an effort goes from being sustainable to unsustainable. 

The reason there’s a ‘theoretically’ floating around is because there are other factors that come into play that limit your performance – such as heat build up and your carbohydrate (energy) stores. Realistically, most people would only be able to ride at CP for about 30 minutes.

Now, there are other ways of measuring/defining the aerobic-anaerobic threshold. To call out a few there’s:

The first three methods all require more advanced and expensive testing equipment as lactate or gas exchange need to be measured, most usually in a laboratory setting. As such, they’re not useful metrics for most riders.

A good old FTP test – going all-out for 20-minutes and multiplying your average watts by 0.95 – is another way of zero-ing in on that threshold point. But, as we’ll get on to later, the tests for CP are a little easier to conduct and gives you a better picture of your personal training zones. 

One significant limitation of FTP is that the power you can put out for 20-minutes doesn’t necessarily correlate to what your maximum power for 1-minute is, or the number of times you can surge above threshold and quickly recover. These are important aspects of your overall performance – and which brings us neatly on to the concept of Watts Prime.

Watts Prime (W’) is defined as the ‘battery’ of energy that we have above CP to maintain power. This is measured in Joules and is a finite – but rechargeable – level of energy. For example, if you had a CP of 300 watts, with a W’ of 20,000 Joules, you would be able to sustain 400 watts for 200 seconds. 

This is because one Watt is equal to one Joule per second. The formula would be W’ / (Interval target watts – CP), so 20,000/(400-300). Theoretically, you could then recharge this battery in 200 seconds if you rode at 200 watts.


Two different testing protocols can be used to determine CP and W’: the ‘3-minute all out’ test, or calculating the power duration curve using two to three intervals of varying length between two and 20 minutes long. 

‘3-minute all out’

The ‘3-minute all out’ test is every bit as painful as it sounds. It involves starting the effort maximally (sprinting from the start) and then holding on to the effort as hard as you can for the entirety of the three minutes. The theory is that, if done truly maximally, the W’ will be drained fully by the final 30 seconds of the three minute effort, and the average power for the final 30 seconds is your maximal power output after W’ depletion; in other words, your CP. 

The amount of energy used above CP during the initial 2.5 minutes is then your W’. It’s a truly horrible test and not a very fun one to repeat too often. Some people may also find they struggle to truly go maximally and then keep pedalling after the initial minute or two of supposed ‘maximal’ work. 

‘2-3 testing intervals’

It is for this reason that the ‘2-3 testing intervals’ method was devised, as it is potentially easier to conduct for the majority of people. This method can be done through two or three efforts, with those efforts ranging from two to 20 minutes. 

Most usually, a 3- and 12-minute maximal paced test is used and has been found to correlate very strongly with the ‘3-minute all out’ test. 

To conduct this test, the athlete warms up well and goes into a 3-minute maximal test – but a paced one – so that power should be fairly consistent throughout the interval. They then ride very easy for ~40 minutes to allow W’ to replenish before conducting a 12-minute maximal test, again paced with consistent power while feeling emptied by the end of this. 

Calculating your Critical Power and Watt Prime numbers 

To get your CP and W’ numbers, the easiest thing to do is just to plug your test values into an online calculator. But for those who are interested: CP is calculated using the slope of the duration of the interval and the work performed, with W’ calculated using the intercept.

Bear in mind, it can still be difficult to pace the 3- and 12-minute efforts correctly, but it is at least generally easier to conduct than a 20- or 60-minute all out test for FTP.

In terms of how often you should be testing, that depends on your racing and training schedule. But a good rule of thumb is every 12 weeks, as that gives a good amount of time to train effectively and achieve the desired adaptations to improve CP and W’. 


We can use CP and W’ in several different ways once we have the test results, depending on the zone or domain model that you use. 

If you’ve come across training zones in cycling before, it was likely Andy Coggan six zones model, where zone four is your FTP, zone five is your VO2 max (so just above threshold, when an effort tips into becoming unsustainable for a long period) and with zone six being everything above that.

With CP and W’, you can add an additional seventh zone for greater specificity when training your anaerobic engine. This generally encompasses the 3-minute test interval power all the way up to maximal sprint.

Another way CP and W’ can be used is as part of the ‘3 Intensity Domain’ model. The first domain – ‘Moderate Intensity’ – is zero watts up to ‘Lactate threshold 1’(LT1), which has been found to correlate well at between 70 to 80 per cent of CP depending on the person. 

This will be a little bit personal to everyone and it’s better to err on the side of a slight underestimation. If you’re over optimistic with this number, you’ll end up negatively impacting your training and pacing by using the wrong energy systems .

The second domain, ‘Heavy Intensity’, is between LT1 and CP and is where exercise starts to utilise more carbohydrate metabolism to maintain output. 

The third and final domain is ‘Severe Intensity’, which includes efforts that deplete W’ and increase the rate of hydrogen ion production (the real culprit – rather than ‘lactic acid’ – which contribute towards fatigue). 

Some models may include a fourth domain, ‘Extreme Intensity’, which is more maximal sprint efforts that use the phosphocreatine pathway for energy production which is both extremely finite and produces inorganic phosphate as a fatiguing metabolite.


Additionally, using the W’ / (interval target watts – CP) formula, you can determine for how long an effort can be maintained. Shifting this formula around a bit can be used to theoretically suggest what power you can produce over a given time frame. 

This is a method I have had quite a lot of success using and has been fairly accurate for efforts up to around an hour. For example, with a CP of 411 watts and W’ of 23,280, for five minutes I could sustain a power of 476 watts. 

My 5 minute power PB at the time was 477 and a Maximal Aerobic Power test I did was 480 watts so it was a fairly accurate prediction. This is particularly useful for hill climbs and time trials where you might have a good idea of the time you should be completing the course in, so you can therefore target an appropriate power to maintain for that duration.


The main ways to achieve an increase in CP involve improving our aerobic performance. To do this, we need to increase the number of mitochondria in our muscles (mitochondrial biogenesis) which help in producing more energy, as well as improving oxygen supply to them by increasing the number of capillaries in the muscles (angiogenesis). 

Interestingly, both these adaptations are signalled by both high and low intensity training. So, when we do high intensity intervals such as VO2max efforts (maybe 4min at 110 to 120 per cent CP with five minutes rest x 4), that sends a signal to the body that it should increase the number of mitochondria in the muscles – which, again, helps with the production of energy.

To be more specific: that signal gets sent via the AMPK (adenosine monophosphate-activated protein kinase) pathway which signals a gene expression called PGC-1α (Peroxisome proliferator-activated receptor gamma coactivator 1-alpha). 

Lower intensity

For angiogenesis (that was increasing the number of capillaries in the muscles to improve oxygen supply), this too takes place with to PGC-1α signalling – but also it also happens as a result of riding at lower intensities, as that activates the vascular endothelial growth factor (VEGF for short).

VEGF activation is one of the reasons why professional cyclists spend so many hours riding at, what is for them, a very low intensity. As a percentage of total training time, the pros tend to spend a much lower proportion in higher intensity zones.

But for riders with less training time available, it is often more beneficial to spend a higher percentage of time in higher intensity training zones relative to the professionals – indoor cycling sessions can provide a quick and effective way to do this. But still, lower intensity training does provide important adaptations and a well balanced training plan should include some sessions focusing on this.


It can be argued that CP and W’ present a far more valid and reliable means of testing fitness and measuring improvements from training than FTP. Testing can show whether improvements have been made primarily due to CP or more due to W’ depending on the goals of the individual. 

For example, you could gain a greater glycolytic capacity (for short sharp efforts like one to two minute hill climbs) whilst seeing no change to your CP. Alternatively, W’ may actually decrease but a higher CP means that the W’ can be recharged at a higher exercise intensity – the upshot of this being that you’d be better able to stay in the group in a punchy road race. 

A CP and W’ test is also potentially easier to conduct than a 20 or 60 minute all out test, as accurate pacing for 3- and 12-minutes is likely easier to achieve for most of us. Also, when using a power duration curve (which can be found on platforms such as Strava), you can reasonably accurately pre-determine the power that can be maintained for a given time frame, or the time frame that a given power can be sustained for, making it far more useful for pacing efforts than FTP testing.

However, there are a few negatives to bear in mind: CP is theoretically sustainable for an infinite amount of time. However, some studies have found that, in several individuals, it was only sustainable for 30 to 35 minutes. 

Even if CP was sustainable for periods above that, there are other fatigue mechanisms that are not accounted for in testing. Heat build-up and carbohydrate availability can both significantly reduce the duration for which exercise in the heavy intensity domain can be maintained. 

Also, using W’ to determine the repeatability of efforts and the recharging of the ’battery’ does not take into account the build-up of fatigue metabolites such as Hydrogen Ions and Inorganic Phosphates which can reduce the muscles’ capacity to perform contractions and produce power. 

Even with these limitations, CP and W’ are still arguably better ways of determining some of the boundaries between exercise intensities, as well as being more valid metrics for determining the power duration curve and training zones than traditional FTP testing.

The importance of Low-Intensity High-Volume Training

We all love a good high-intensity smash fest, be it on the road or in the Pain Cave on the turbo. And, of course, these high-intensity sessions are vitally important to our training, helping us get fitter and faster through various means. But there is arguably an even greater importance for the inclusion of low-intensity high-volume training, so let’s dive into why this is the case…

We may not have the time available to train like the pros, who will be doing 25+ hours of training a week. But, interestingly enough, we probably do a similar amount of higher-intensity each week as they do at times. So, what do they do differently? The answer is: a lot of low-intensity high-volume training – which is used to facilitate more potential gains from the high-intensity work that they also do. 

As can be seen here, most training time for professional cyclists is spent at lower intensities. From: Van Erp, T., Sanders, D., & De Koning, J. J. (2019). Training characteristics of male and female professional road cyclists: a 4-year retrospective analysis. International journal of sports physiology and performance15(4), 534-540.

We can improve our aerobic power via a few different methods but many of them come down to something called PGC-1α (Peroxisome proliferator-activated receptor gamma coactivator 1-alpha). One of the primary things that PGC-1α does is to increase mitochondrial biogenesis, therefore increasing the number of cells within our muscles that oxidise fat, carbohydrates and lactate to produce ATP (adenosine triphosphate) – which is what our body uses to energise all muscular processes. Another benefit of increased PGC-1α expression is that insulin-stimulated glucose transport is increased (also called increased insulin sensitivity) via GLUT4 (Glucose Transporter Type 4). Essentially, this means that we can deal with carbohydrate loads better without the associated blood sugar highs and lows, as blood sugars remain more stable.

The first method of activating PGC-1α that we’ll discuss occurs due to high-intensity exercise and is achieved via the AMP-K (adenosine monophosphate-activated protein kinase) enzyme. The AMP-K facilitated PGC-1α signalling occurs during high-intensity due to the ratio of AMP:ATP increasing. This is because ATP is being used at a rate faster than it can be generated, such as during very high-intensity exercise that is not sustainable. So, those hard interval sessions being set for you will be contributing towards improving your aerobic function along with other training benefits. 

There’s still an important place for high-intensity sessions in making aerobic endurance gains (among other benefits)

However, low-intensity high-volume training sessions can also cause PGC-1α signalling to occur in a different way. When we contract our muscles, calcium is secreted into the cytoplasm from the sarcoplasmic reticulum. This in turn activates CAMKII (calcium/calmodulin-dependent protein kinase), which is itself a signalling molecule for p38 MAPK (p38 mitogen activated protein kinase). p38 MAPK not only increases PGC-1α after the initial uptake of exercise, but also increases the expression of PGC-1α as exercise continues, thus improving mitochondrial biogenesis, oxidative capacity and aerobic performance. Due to the continuous nature of this signalling pathway, high-volume exercise is more beneficial than shorter in this respect. The only way to conduct this exercise sustainably is to perform it at lower intensities. 

Another benefit of low-intensity high-volume exercise is something called angiogenesis, or muscle capillarisation, which is the creation of new capillaries within the muscle, allowing more oxygen to be transported around the muscle and therefore improving oxidative capacity. This can also be facilitated via PGC-1α signalling to a lesser degree. However, the primary driver for angiogensis is VEGF (vascular endothelial growth factor), which is secreted from the muscle fibres to the muscle interstitium. Additionally, studies have found that, as intensity increases, VEGF activation decreases and angiogenesis is hampered, which is why low-intensity exercise is so important for angiogenesis. These benefits are theorised to occur more in the high-volume exercise due to, again, the continued muscle contractions over far longer time durations than for, say, 60 minutes of high-intensity training.

Winter base miles are a staple in many cyclists training plans. Group rides offer (for most) a more enjoyable way of getting in those low-intensity high-volume training rides

Finally, low-intensity long-duration training helps with improving lactate clearance. Lactate is produced during the breakdown of glucose, primarily in the Fast Twitch Glycolytic muscle fibres, and is then released into the blood and converted to pyruvate in the liver (takes minutes), or can be used directly by Slow Twitch muscle fibres and converted into pyruvate and used to synthesise ATP (far quicker process). Low-intensity high-volume training (and high-intensity training) increases the transporter MCT-4 (Monocarboxylate-4) which helps remove lactate from those Fast Twitch muscle fibres rather than lactate entering the blood stream. This means that the lactate can be used to synthesise additional ATP at a faster rate (improved clearance). Another way in which low-intensity high-volume training improves lactate clearance is by increasing the amount of another transporter called MCT-1 (Monocarboxylate-1) and the enzyme mLDH (mitochondrial lactate dehydrogenase). MCT-1 takes lactate into the Slow Twitch muscle fibres where mLDH converts it into pyruvate in the mitochondria, where it is then used to synthesise ATP. Finally, with low-intensity long-duration training increasing the amount of mitochondrial biogenesis in Slow Twitch Muscle Fibres, there are greater numbers of mitochondria to break down the lactate via mLDH and synthesise it into ATP.

So, what is low-intensity training? Traditionally, it is referred to as Zone 1 or Zone 2 exercise, something that is easily maintainable over long durations while being able to maintain conversations. Physiologically, it is the moderate exercise intensity domain which refers to exercise that is below LT (lactate threshold), where the primary fuel oxidised is fatty acids and lactate production does not increase from base levels. A general rule of thumb for this is exercise performed at less than 70% of Functional Threshold Power, but LT for individuals varies in terms of their percentage of FTP and can also change based on environmental factors such as heat and even fatigue. Additionally, sub-LT is often an intensity that maintains the Heart Rate to Watts ratio without cardiac drift occurring. Cardiac drift, also referred to as aerobic-decoupling, is when HR increases compared to power in a non-linear fashion. So, either power stays the same and HR increases, power drops and HR remains static, or power increases but HR increases at a rate that is exponentially higher than would be expected.

Time spent in power zones over the last 730 days for one of the professional riders that we work with

What does this mean for everyone reading this? Fortunately, you don’t need to be doing 4+ hour rides 5 times a week to reap the benefits of long duration low-intensity training. Getting one or two longer rides at a low-intensity in at the weekend will help you significantly with your aerobic fitness, as well as providing a good base to build upon using high-intensity sessions. So, although suffering and doing high intensity sessions to make the Pain Cave earn its name are important, don’t forget the importance of those long slow endurance rides when you can fit them in.

For further reading on PGC-1α, have a look at this research paper: Jung, S., & Kim, K. (2014). Exercise-induced PGC-1α transcriptional factors in skeletal muscle. Integrative medicine research3(4), 155–160.

For more info on angiogenesis, this is a great read: Gliemann, L. Training for skeletal muscle capillarization: a Janus-faced role of exercise intensity? Eur J Appl Physiol 1161443–1444 (2016).

The end of FTP Tests? – Why you should use Critical Power and Watts Prime instead of Functional Threshold Power

(originally posted on Rule28 Performance Hub 22/4/22)

Coach Any Turner discusses why focusing on FTP tests can result in worse race day performance and what you can do about it.

FTP has been a talking (bragging) point for cyclists since power meters have gained in popularity. Classic café stop talking points are what someone’s FTP is compared to their mate’s or how much your FTP has gone up by since the last test.

Training plans often focus on boosting your FTP, but how useful is this really? For those that don’t know, Functional Threshold Power is often referred to as the maximum amount of power a rider can put out over 60mins. This number can be gathered either by undertaking a 60 min all-out effort or taking 95% of a 20min effort.

FTP is limited in usefulness however. Training for maximum 20 or 60min power has limited utility in race conditions. It’s all well and good having a great 20+ minute power, but if we can’t follow those critical maximal attacks above ‘threshold’ then we’re unlikely to be winning any races. To learn more about our capacity for those sorts of efforts in addition to our threshold, we need to test and train for something different.

“The critical power (CP) is mathematically defined as the power-asymptote of the hyperbolic relationship between power output and time-to-exhaustion. Physiologically, the CP represents the boundary between the steady-state and nonsteady state exercise intensity domains” Vanhatalo et al., 2011. While Watts Prime (W’) has been described as the finite work capacity above CP.

W' and CP Critical Power Rule 28

Figure 1. Shaded blocks equal the W’, all the boxes have the same sized area. The curved line represents the power curve for this rider’s power. The straight line represents CP. Theoretically these lines never touch.

A bit sciencey that explanation, but essentially CP tells us when exercise goes from being sustainable for long durations, to non-sustainable. CP and W’ have become more common testing metrics in recent years for several reasons. They are easier to test than FTP, especially out on the road, and mentally the shorter efforts can be easier to conduct. This form of test also tells you more about your overall power curve as well as your power at non-steady state exercise intensity domains i.e. Full Gas! The test is typically done in one of two ways:

The first way is the 3 minute all out test (Burnley et al., 2006). This means sprinting all out from the gun, with the idea being that the final 30 seconds you will have exhausted your W’ reserve and only be able to ride at your CP. CP is measured as the average power for the final 30 seconds, and W’ is measured as the work done (joules) above CP for the first 2.5 minutes. This test can be difficult to conduct properly as often people leave a little reserve still in the tank and up the power in the final seconds of the effort, skewing the results slightly.

The second method is done by using different lengths of interval with appropriate recovery in-between. The number of efforts and duration varies from tester to tester, with some going for three to four time durations varying typically between 3 and 20 minutes long (Maturana et al., 2018). Typically, accurate results can be achieved by testing for 3 and 12 minutes durations (Simpson & Kordi, 2017) and from those maximal efforts, W’ and CP are derived. It’s not perfect by any means, as day to day variations in power occur as well CP being theoretically holdable forever (it isn’t), but it does offer a better picture of the overall physiological capabilities and limitations of a rider than doing an FTP test.  

Power Sustain Duration Rule 28

Figure 2. Curved line used to determine time at which certain watts can be sustained for. Linear line to determine what power can be sustained for a given time frame.

The results of this test not only give you a supposedly more accurate/attainable sustainable power output over longer durations, but also an ‘anaerobic’ capacity, or battery, that can be drained and recharged depending on the power output. The results can also be used to determine other useful factors, such as maximal power over a certain time duration or for how long they can maintain a certain power output above CP. So for those targeting a hill climb with a target time of 6 minutes, you can use the calculation to determine what power you can maximally maintain for that duration.

To summarise: CP and W’ present a more helpful set of test results than FTP. Give you information about your anaerobic capabilities. Can be used to determine how long you can maintain a certain power for, or what power you can maintain for a certain timeframe.

Find out more about coaching from Andy Turner here


Jones, A. M., Vanhatalo, A., Burnley, M., Morton, R. H., & Poole, D. C. (2010). Critical power: implications for determination of VO2max and exercise tolerance. Med Sci Sports Exerc42(10), 1876-90.  (Figure 1)

Burnley, M., Doust, J. H., & Vanhatalo, A. (2006). A 3-min all-out test to determine peak oxygen uptake and the maximal steady state. Medicine and science in sports and exercise38(11), 1995-2003.

Maturana, F. M., Fontana, F. Y., Pogliaghi, S., Passfield, L., & Murias, J. M. (2018). Critical power: how different protocols and models affect its determination. Journal of Science and Medicine in Sport21(7), 742-747.

Vanhatalo, A., Jones, A. M., & Burnley, M. (2011). Application of critical power in sport. International journal of sports physiology and performance6(1), 128-136. (Figure 2)

Simpson, L. P., & Kordi, M. (2017). Comparison of critical power and W′ derived from 2 or 3 maximal tests. International Journal of Sports Physiology and Performance12(6), 825-830.