Cool down to come back to earth gently. Don't expect it to stop you aching.
A cool-down is the five or ten minutes of easy jogging and walking that ends a run. Every session in our plans has one, and most people skip it.
What it genuinely does
Stops you stopping dead. During hard running your heart is pumping hard and your leg muscles are helping push blood back up. Halt abruptly and that help disappears while your heart rate is still high — which is why people feel light-headed after sprinting to a finish and then standing still.
Brings you down gradually. Heart rate, breathing and body temperature all return to normal more smoothly, which most people simply find more pleasant.
Marks the end. Not physiology, but real: a few minutes of jogging is when a session stops being a session, and it is when the good conversations happen. Ours tend to happen on the walk to Coffee House.
What it probably doesn’t do
Here is where the honesty comes in. Cooling down and stretching afterwards do not reliably prevent next-day soreness. This has been tested repeatedly and the effect is small to non-existent. If someone tells you their stretching routine eliminates DOMS, they are describing a placebo they enjoy.
Nor does it “flush out lactic acid” — lactate is cleared within an hour whatever you do, and it was never the thing making you sore anyway. The soreness is microscopic muscle damage, and it needs time, not stretching.
So what should you actually do
- 5–10 minutes easy jogging, dropping to a walk
- Longer after a hard interval session than after an easy run
- After that, stretch if you enjoy it — for how it feels, not for what it prevents
- Drink something, eat something within the hour if it was a long one — see fuelling
Ten minutes. It is the cheapest part of the session and the first one everybody drops.