Second Wind

Gasping, legs burning, you slow to a walk. Hands on your hips, you look up and wonder how you’ll get to the top. But after a minute, you feel so much better and manage to power to the summit! Where did that second wind come from? Dr Gabe Mirkin has answers, and they might not be what you expect.

When you run very fast, you reach a point where you gasp for breath and your muscles burn so much that you feel like you have to slow down, but you try to keep on pushing. Soon you feel recovered and pick up the pace.

We used to think that second wind meant that you slowed down to allow yourself time to recover from your oxygen debt, but research from the University of California in Berkeley gives another explanation.

After you slowed down briefly, you felt better and could pick up the pace because the same lactic acid that caused the burning in your muscles and shortness of breath could be used as an efficient source of energy for your muscles.

Since lactic acid requires less oxygen to power your muscles than most other sources of energy, you catch up on your oxygen debt, the concentration of lactic acid in your muscles drops, the burning and gasping lessens, you feel better and you can pick up the pace.

ENERGY CYCLE