Does It Matter When I Exercise?

Its more so how your energy levels operate at certain times of the day as opposed to what the clock says. -Nate

(MSNBC) It's true that studies have suggested the body functions more efficiently at different times of the day. Some reports, for instance, have shown that the body's processes are slowest in the morning. Others have found that in the afternoon, strength and aerobic capacity are greatest, suggesting that it might be best to exercise at this time.

However, there are two basic principles to exercise that are even more important: If you're both consistent and patient with your training, you'll reap the benefits, says Joel Friel, author of: The Cyclist's Training Bible, and:The Triathlete's Training Bible.

Friel, an exercise science expert, points out that studies done in the past several years have shown that important aspects of a person's workout are not affected by time of day, such as how long you can go before exhaustion. Perceived effort remains the same throughout the day, too, meaning a workout doesn't feel harder in the evening than it would in the morning.

Other factors play a part as well. Pollution is heavier in the afternoon, which may affect your breathing. So running, cycling and other outdoor activities done in the early morning or after the evening rush hour may be better. The hot afternoon sun may also be a factor that makes early morning or evening exercise a better choice.

The bottom line, says Friel, is that it's most important to find what time of day works best for you and to commit to a fitness routine. So if exercising at night works best because you work full-time, stick with it.