REACH YOUR PEAK
Boost your performance with the latest sports science and tech findings
Fancy a scientist extracting a segment of your muscle fibre within a day of hardcore intervals? Doubtful. Fancy that same scientist extracting four segments of muscle fibres during a day of hardcore intervals? Sod off. That’s what a brave set of Danish cyclists let a team of Danish researchers do to their thighs, all in the name of finding out more about the role of muscle glycogen in high-intensity exercise. From our point of view, their suffering was worth it as it’s given us a deeper insight into why your power output drops after two hours of chasing your mate’s chamois or from battering yourself round Watopia.
Eighteen cyclists performed high-intensity, intermittent, glycogen-depleting intervals. They were then randomly assigned to the high-carbohydrate diet group, who’d scoff bars and consume drinks, or the low-carbohydrate placebo group. After 5hrs, the scientists assessed their repeat sprint ability by having them undertake 5 x 6sec maximal sprints with 24secs rest in between. Throughout the day’s tests, muscle biopsies were taken, as well as blood samples.
So, what did the vampires find? On a fundamental level, it was as you’d expect. The first set of intervals reduced both groups’ muscle-glycogen stores, while the high-carbohydrate group then enjoyed greater glycogen replenishment. That showed in the final 5 x 6sec maximal sprints as they performed better than the placebo group and they found it easier (their rate of perceived exertion scores were lower).
Nothing new there. But when the scientists dug deeper, they showed that in the low-carb group, 19% of individual slow-twitch fibres and 4% of fast-twitch fibres were depleted to less than 20% of their original levels. No individual fibres in the high-carb group were that depleted, inferring that even if the majority of your muscle fibres are loaded with glycogen, those that aren’t will compromise performance.
At an even deeper level, they discovered that
how glycogen is stored matters, too. In a muscle fibre, it’s stored in three places: subsarcolemmal, intermyofibrillar and intramyofibrillar. The latter’s associated with contraction and, true to form, in the low-carb group, over half the subjects’ intramyofibrillar was depleted to less than 20%. The conclusion? It’s not just muscle-fibre quantity that matters, but where it’s stored in the muscle.
Takeaway There’s still much to learn about glycogen and muscles at a cellular level. But, in general, carbohydrate feeding before, during and after cycling will help you ride better
“19% OF SLOW-TWITCH MUSCLE FIBRES AND 4% OF FAST-TWITCH WERE SEVERELY DEPLETED”
“IF YOUR NERVOUS SYSTEM’S STRESSED, YOU SHOULD TONE DOWN THAT DAY’S TRAINING”
02 One for the summer
A team from Birmingham University has shown that riders rode stronger in a 4km time trial after consuming sodium bicarbonate in the heat (30°C) via the same mechanism as they used in more temperate conditions. That mechanism is ‘buffering’; in other words, when ingested, the alkaline nature of sodium bicarbonate (baking soda) raises the pH of blood. As highintensity riding generates lactic acid, which ultimately lowers the pH of blood making it more acidic, the idea is that baking soda gives you longer to work hard before your acidic blood slows you down. The researchers noted the ergogenic effect came at just 0.2g/ kg bodyweight compared to the traditional 0.3g, meaning common gastro issues might be avoided. Baking soda also retains water, so may help in longer hot rides. Takeaway Baking soda could have benefits in all conditions. But too much can cause stomach upsets for some
03 Customised progression
HRV measures your ‘state of readiness’, mainly by assessing your autonomic nervous system. If your nervous system’s stressed, you should tone down that day’s training. If it’s not, go for it. Research is equivocal on its benefits, but a recent study from Finland is in the ‘for’ camp after researchers found that endurance runners whose training load was managed twice weekly by their nocturnal HRV score and recovery status outperformed those who followed an off-the-peg programme. In our experience, HRVTraining is one of the most reputable apps. It’s available on iOS and Android. Takeaway HRV training learns with you, so the more you use it, the more impact it will have. A reading as soon as you awake is preferable
04 Focus and distract
In pain? It’s time to focus… A German team had 58 athletes run 9 x 3min outdoors around a large pond. While running at three intensities, they were instructed to focus on their breathing, on the environment or did not receive an instruction. In light activity, ‘nonfocusing attention’ was deemed most effective, but when it came to hard efforts, a self-audit, like focusing on breathing, proved most beneficial. Paying attention to your environment also seemed to help. Takeaway This and other mind-trickery techniques, like self-talk and visualisation, are easy wins HRV (heart rate variability) training is flirted with the masses for the past few years, especially as smartphones and wrist-based training tools have become more sophisticated. The idea is that
05 Power adaptor
Weight training is used by all levels of cyclist, with the aim of reducing injury and increasing power. But there’s a school of thought that says strength training could inhibit performance because the weight movements just aren’t specific enough. For instance, squats and leg presses are quite different to pedalling technique. Well, a recent UK study dispels this notion. After a 12-week gym plan – two sessions a week – that complemented their cycling, the participants’ crank power increased significantly, showing both the nervous system and muscles had adapted. Takeaway Strength training is another easy win this winter