A couple of facts (and fictions) about the burning sensation we all know and struggle to love
FACT
It’s a source of energy. Lactic acid, or lactate, is a chemical that your body produces 24/7, even while you’re doing nothing, saysDr L. Bruce Gladden, professor of kinesiology at Auburn University. Its purpose? To feed your muscles so
you can move.
FACT
It’s made in different ways.
When you’re spinning along comfortably, your body primarily gets energy via a slow but steady process that converts fat to fuel. But when you put the hammer down, muscles need fuel faster, so they use a speedier process that taps stored carbs, or glycogen. Both methods produce lactic acid, which helps supply energy to muscles. The more carbs the body uses, the more lactate accumulates in the muscles and blood.
FICTION
You can blame it for the burn.
Lactic acid is not what makes your legs threaten mutiny when you’re climbing or going hard. If anything, it delays the point at which you fatigue by providing fast energy when you’re pushing into the red. The burn you feel when you hit your limit is probably the result of your nervous system sensing increased acidity from the accumulated lactate, Gladden says.
FICTION
It causes post-ride soreness.
In fact, when you ease the pace, the rate at which your body pumps out lactate slows. It doesn’t pool in your legs and make them hurt. Next-day soreness is more likely the result of damage to muscle and connective tissue, or plain old inflammation.
HOW YOU CAN TRAIN IT
“The better you are at using lactate for energy,” says Gladden, “the better your exercise endurance.” You can teach your body to use lactate more efficiently by putting in lots of kilometres. But upping your intensity will do the trick in less time. Structure your rides so you spend 10 to 20 per cent of the time going hard, at an exertion level of 70 to 80 per cent (or higher) of your all-out effort.
QUICK QUIZ
What is the maximum number of minutes it takes for your body to use (or clear) lactate after you finish riding?
ANSWER
60. Clear it faster by cooling down with some light spinning.