Not only do you get slower despite working harder, but studies show you also risk depression, chronic fatigue, insomnia and a weakened immune system.
Now, thanks to Finnish researcher Heikki Rusko, Ph.D., there's a reliable test to see if you've been overtraining. Better still, it'll warn you if you're on the verge of overtraining, giving you time to adjust before the bottom falls out.
Here's how it works:
1. Lie quietly for 10 minutes, then stand up and wait exactly 12 seconds before counting your pulse for six seconds. Write this number down.
2. Next, starting precisely 90 seconds after you stood up, count your pulse again, but this time for 30 seconds. Write this number down.
3. Now convert these two numbers to heart rates (beats per minute) by multiplying the first reading by 10 and the second by two.
Do this test every day at the same time of day. If you are not overtrained, these two readings will remain remarkably constant from day to day. If you're overtrained, or heading in that direction, you'll see a gradual rise in your heart rates especially in your later reading.
Rusko found that overtrained Finnish cross-country skiers showed 10- to 15-beat-per-minute increases in their second readings over a four-week period.
The gradual increase gave the Finns time to ease up on their training. So take the test; you may need the rest.