How To

Six things you need to know about… detraining

How long does it take to lose fitness?

Seeing a natural progression in your fitness as you train is one of the most satisfying experiences in cycling. At the start of the year you were being dropped on the group ride, but now it’s you dropping your buddies on the climb. However, just as you accumulate fitness over time, you can just as easily lose it if you have time off the bike.

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Perhaps it’s an injury which has stopped you from riding or you’ve just fallen out of the routine. Maybe commitments away from cycling have stopped you training. It’s also not uncommon at this time of year that, having had a well-earned rest after summer, you may have found you’ve had longer than expected off the bike.

When does detraining start?

We all know that if you train hard and allow sufficient recovery then your body will respond and adapt to that training, and you’ll get stronger and fitter. Well, unfortunately the reverse is also true.

Stop training for a prolonged period of time and you’ll start to lose those gains and your fitness will begin to gradually decline. This is the principle of reversibility; essentially, when it comes to fitness, you need to use it or lose it!

Detraining shouldn’t be confused with adequate recovery. As I’ve covered in detail before, recovery is a crucial part of any training plan, and without adequate recovery you will never give your body the chance to adapt to the training stress you’re putting on it. It’s during this recovery phase that your body rebuilds to become stronger and, without adequate recovery, your fitness will plateau as you will be too tired to make the most of the training you are doing.

Detraining is what occurs after the recovery process (and the length of this depends on the intensity of your training programme) has finished. If you continue to take time off the bike once you have fully recovered then you will start to move into the territory of detraining and will lose fitness, rather than gain it.

How quickly do you lose fitness?  (Pic: Media24)

How quickly will I lose fitness?

Detraining beings to occur after 3-5 days of no activity, though any losses at this stage are very small. It won’t start earlier as your body is busy processing the training you have done, repairing muscle damage and topping up glycogen levels.

After around five days your blood volume will start to decrease. This means your ability to carry oxygen from the lungs to your muscles decreases and is the reason your heart rate will be a lot higher when riding after a prolonged break for a given intensity – you aren’t as efficient in moving oxygen around the body so your heart has to pump more to provide the muscles with the oxygen they need.

After around ten days of detraining, your VO2 Max – the maximal amount of oxygen you can take in and process – starts to decline. One of the reasons for this is that at around day ten you are starting to see a decrease in the amount of mitochondria you have in your muscles (mitochondria are the power stations in your muscles, which use oxygen to produce energy).

In addition to this, the amount of respiratory enzymes (the molecular devices that allows us to process oxygen, glycogen, fat etc.) also decrease in number. The combination of the two simply means you can’t process and use as much oxygen as you were previously able to

By the two-week mark you will begin to feel a noticeable reduction in fitness. At this point, your VO2 Max may be as much as 20 per cent lower than it was. Of course, the level of decline varies from person to person, but you will see a significant fall in VO2 Max after two to four weeks of detraining and you will start to experience a reduction in stroke volume – or the amount of blood your heart pumps per beat.

From here, the declines continue. Stroke volume will continue to decrease, your mitochondria will continue to become less efficient at using oxygen to produce energy, and you may begin to lose muscle mass and gain body fat.

Your top-end fitness will suffer first (Pic: Giant-Alpecin)

Speed vs. endurance – what does this mean on the bike?

Coaches often describe fitness as a pyramid. Your base aerobic fitness is the wide part at the bottom and your top-end race fitness is the apex. Detraining begins to break down the fitness pyramid from the top down, so you will lose top-end performance first and then base fitness much later on.

As I’ve already covered, your VO2 Max is one of the first physiological factors to be affected by time off the bike. VO2 Max is key when it comes to high-end performance, so as the maximal amount of oxygen you can take in decreases, so does the level to which you can perform over the course of 2-5 minute efforts, when VO2 Max – and your ability to deliver large amounts of oxygen to your muscles – is crucial.

Strength is another area that will suffer as a result of detraining. Interestingly, strength work gained from weightlifting seems to be better retained than aerobic capacity. Two weeks of inactivity won’t see the same decrease in how much you can lift in the gym compared with what you will have lost in terms of aerobic capacity, but your ability to apply that strength on the bike will be reduced.

Detraining begins after 3-5 days but the effects are small to begin with (Pic: Christopher Keiser)

Power on the bike is how fast your turn the pedals (cadence) multiplied by how hard you are pushing on the pedals (torque), so since cadence tends to remain constant when detrained compared to when you are fit, then any loss in strength will have a direct impact on how much power you can produce.

Endurance is the last thing to be affected and it’s for this reason that after a break you can return to endurance training without too many problems. However, in terms of endurance, what is affected is your efficiency – for a certain heart rate you will be producing less power.

As a result, on returning to training you should be ok to go out and ride for a prolonged period but you shouldn’t expect to do it at the same average speed or average power as you were managing before your break. That’ll come – but how long will it take?

How long does it take to regain fitness?

Unfortunately, it can take longer to regain what you have lost that it took to lose it in the first place.

One famous case study of an Olympic rower showed that after an eight-week break post-Olympics it took him 20 weeks to return to his previous level of fitness.

However, this is also an elite athlete at the very peak of his powers and an athlete with less to lose, particularly in terms of top-end form, may not face the same long road back to form.

Ease yourself back in slowly when you return to training (Pic: Science in Sport)

Evidence also suggests that, particularly when it comes to endurance, experienced athletes will hold on to their fitness longer than those new to the sport, so don’t panic – just because you’ve lose fitness, it doesn’t mean you can’t soon regain it and move on to better things.

After a prolonged break, I find that it takes between seven and ten days to start feeling normal on the bike again. The first few days will be a struggle but after a week or so you should feel ok to start increasing the training load, and then you’re well on the road to recovery.

How long it will take you to surpass your previous fitness will depend significantly from rider to rider, depending on their physiology, their previous fitness, the extent to which they have avoided physical activity and other factors.

Either way, habit counts for a lot and the first thing to do is to grab the bull by the horns and get back on the bike. The best way to then make strides forward is with a solid training plan of attack.

Plan your comeback and you’ll be flying again before you know it

What’s the most effective way to regain fitness?

One thing to be very aware of on resuming training is not to do too much too soon. Remember, you quite simply aren’t as fit as you once were so you won’t be able to handle the same amount of training. Build up slowly, especially during the first couple of weeks, and give your body the chance to get back into the swing of things. What you really want to avoid is going too hard and making yourself too tired. You’ll only have to miss more training down the line to allow your body to recover.

After a period of inactivity, I often get my coaching clients to include both strength (torque) and cadence work in their training when they return to the bike. This isolates the two aspects of power production and, by working on them in isolation, you can make gains in both quicker. Put the two elements back together and you should be well on the way to returning to fitness.

Another benefit of working on both strength and cadence following a break is that it forces your body and brain to remember the patterns of muscular contractions involved in pedaling. Just as you see a reduction in physiology following a break, the same can be said for your neuromuscular attributes, and it’s just as important to work on this as the physical side of things.

How can I avoid detraining?

Sometimes it simply isn’t possible to avoid a period without training. There are, however, a few things you can do to limit your fitness losses.

Firstly, take the stairs. It’s amazing how small changes in our daily lives can make a big difference. Something I often tell my coaching clients to do when away on holiday is to take the stairs instead of a lift or escalator. This is such a small change but helps to maintain muscle strength and keeps you active.

Even the smallest amount of physical activity helps. Any cycling activity you do will be beneficial. This can be as little as a ten-minute spin on the turbo. Physiologically, the effects of such a short session are likely to be very small, however it acts as a mental reminder for your body. The mental side of things shouldn’t be underestimated, so any reminder you can give your body will help to retain muscle memory.

Take the stairs – but you don’t always need to take your bike with you (Pic: Balint Hamvas)

Finally, refocus mentally. Fatigue is often as much about mental fatigue as it is about physical fatigue. A period where you aren’t training can be used to refocus mentally and recharge the motivation banks ready for your return to cycling. I give each client I train a break each year and one thing I always say is to take five to seven days more off the bike than you feel you need.

This means that on returning to training you are chomping at the bit to get going again and are ready to commit fully to your training plan.

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