Photo by knox_triA recent issue of Running Research News (Volume 23 Issue 5) has an article about overuse muscle damage in runners and it’s effects on performance. The article analyzes the results of research published in the Scandinavian Journal of Medicine & Science in Sports and concludes that aerobic performance is not negatively impacted by sore muscles. The relatively poor performance is actually caused by the brain due to an increase in the perceived effort of running.

The testing involved 24 men and 6 women who ran two 30 minute time trials. Between the two time trials, the test group did 10 sets of 10 drop jumps. The second time trial was 48 hours after the drop jumps.

The researchers discovered that there was no change in oxygen consumption, heart rate, energy metabolism or running economy, which are all markers of athletic performance and ability. The test group was not able to run as far in the second time trial. The control group, who did not do the extra workout, managed to (slightly) increase the distance they could run in 30 minutes.

The runners all felt that their perceived effort was the same the second time as it was the first time. The test group, however, had elevated levels of interleukin-1β. Interleukin-1β is a chemical in the brain associated with muscle damage. When it is present, we perceive the effort that we are putting forth to be greater than it actually is; when it is not present, then a similar effort will seem easier.

It is not much of a stretch to relate poor racing performance after a tough workout to mental problems rather than physical problems with the muscles themselves, when the common markers for athletic performance are not actually inhibited. The chemical seems to be produced to help keep us from injuring ourselves by over training, though, so it is not necessarily something that you would want to ignore.

The article had some basic suggestions for recovery after exercise-induced muscle damage:

• Fueling on a daily basis with proper nutrition.
• Recovering between workouts with adequate sleep and easier training (or rest days).
• Taking it easy when muscles are sore.
• Increasing your training volume and intensity gradually.

Their tips are good general advice, but not particularly enlightening. The research was interesting, though.