It’s inevitable that you’ll get sidetracked from your training routine. Life happens. You go on a trip, sprain your ankle, start a new job, and when you do find time to get back to training, you end up feeling weak and out of breath. It may feel like all your hard work has been for nothing. But it’s not.
You’ll be surprised at how quickly your energy levels drop, but they don’t bounce back. And even if your circumstances prevent you from following your normal routine, there are things you can do to minimize the loss of energy.
How quickly your fitness declines depends on which aspect of fitness you consider. When it comes to aerobic fitness, the situation is the worst: Evidence shows that VO2 max, the maximum rate at which your body can absorb oxygen, drops significantly after just 12 days of inactivity. This is mainly because the amount of blood your heart can pump with each beat drops by about 10 percent.
Some changes happen even faster: after two days of rest, for example, blood volume decreases, and after a month, the capillaries that supply oxygen to muscles also decrease, likely due to changes in levels of proteins that affect capillary formation.
Out of breath
In a June preprint paper, Adam Sharples of the Norwegian School of Sport Sciences and his colleagues found that…