We've all heard about how quickly you lose fitness once you become sedentary. As a rule of thumb, the old adage says that it takes twice as long as the layoff period to return to your fitness peak. But will it really take 1 year to return to where I was? After these last 4 weeks of slogging through workouts, I beginning to think that maybe it will.
The last issue of Triathlete mag (Dec' 10) gave me some hope. Dr. Jeffrey Sankoff wrote a little blurb on "Memory Muscle" addressing exactly this question. Have I lost everything after my 6 month layoff despite 7 years of previous hard work? Scientists from Norway found that muscles in previously trained mice remained "primed" to return to fitness after a layoff, despite a loss in muscle mass. It seems that muscles do have a memory, and this may help seasoned athletes regain fitness faster than untrained ones after a sedentary period. I can only hope this proves to be true for humans!
So what is detraining and how fast does it happen? Detraining is the loss of fitness due to inactivity, occurring in as little as 2-3 weeks. First, our VO2 max decreases, or to put it simply, cardiovascular fitness. You start huffing and puffing. Then, you lose muscle mass. In addition, your body is less effective at fat-burning and stores less glycogen. It can take up to 6 months to regain fitness after a long layoff. Easy come, easy go.
From what I've read, it's always better to reduce training than stop altogether. This prevents a dramtic reduction in fitness and also allows athletes to bounce back faster. And when returning to training after a layoff, always start slow. Consistency, not intensity speed or distance, is the key.
Links on Detraining: