In this age of online training plans and workouts, do you ever find yourself with a burning question you’d like to directly ask a cycling coach? Well, now is your chance to ask away! In this series, we’ll be putting your questions to expert coaches – send them in at anna.abram@futurenet.com.
I won’t lie, when I saw this question come in for my weekly article, I was rubbing my hands together – a chance to get stuck into some real exercise physiology. Don’t worry though, I won’t start just throwing technical terms around – well, not just yet anyway…
To answer this question we need to understand – during very hard exercise – what exactly is going on there in the leg muscles and what it is that forces us to start breathing harder.
Sports scientist and coach James Spragg is one of the experts who will be answering your questions in Cycling Weekly’s ASK A CYCLING COACH series which comes out every Wednesday. Working both in research and applied settings, he currently runs Intercept Performance Consultancy.
Let’s start with the legs…
(Image credit: Future)
During very hard exercise such a VO2 max session or during anaerobic efforts, there are several changes that happen within the leg muscles. You have all probably heard about lactate (sometimes incorrectly called lactic acid) and how its build up causes our legs to burn and stops us from exercising… well, I am here to tell you that is completely incorrect.
Lactate is certainly produced but it doesn’t cause our legs to burn, nor does it stop us from exercising. In fact, without it, things would be a lot worse. Let me explain.
You might remember from biology class a substance called ATP – ATP is basically a micro battery that can be used to transfer energy around the cell. Every time our leg muscles contract, we break down ATP. However, there is only a limited amount of ATP available; so, if we want to keep going, we need a way of putting ATP back together. We have several ways to do this. The phosphocreatine (PCr) system, the glycolytic system, and the aerobic system. Okay yes, we’re getting technical with this one…
To put ATP back together, we first break down PCr, but in doing so we release the P from the Cr. This is bad news as the P part – or inorganic phosphate as we call it – interferes with how well the muscle contracts. Too much inorganic phosphate means that you won’t be able to continue cycling. It’s inorganic phosphate that’s the bad guy in terms…