The science behind an active break

Let's see what the scientific literature says about detraining, specifically at the muscular level, for highly trained athletes, averagely trained individuals , and absolute beginners.

Aerobic workouts vs strength workouts

The most important difference to note concerns aerobic training and strength training.

The parameters studied by the various studies have shown that aerobic performance suffers much more during long breaks, unlike strength performance which does not seem to undergo major changes even after 2-4 weeks of break. Even after 2 months of pausing training, the loss of strength is limited to only 7-12%.

Force

Strength gained recently, i.e. if you've only started training for a few weeks, is lost at a different rate. A stop of just one week does not cause any significant loss of strength, while stops longer than 4 weeks result in a proportionally greater loss.

However, it's important to note that strength levels still remain higher than when you weren't training. There is no going back to zero point!

A stop can allow recovery from accumulated fatigue, and increase the speed with which the muscles contract.

As far as aerobic performance is concerned, we have several studies demonstrating how the various parameters involved decrease after even brief suspensions of training.

Several studies in the literature show significant reductions in Vo2Max in athletes after 3-6 weeks. The same is true for capillary density, oxidative capacity, muscle cross section and electromyographic activity.

Capillary Density

Studies on capillary density are conflicting: in some cases it was seen to decrease after only 15 days of a break in well-trained endurance athletes, in another study no differences were seen after almost 3 months of detraining. Only one study evaluated capillary density in people who had been training for a short time, finding a significant decrease in capillary density after 4 weeks of detraining, but with values ​​still higher than the pre-training period.

It would seem instead that the loss of aerobic capacity in the first 2 weeks is due to a decreased stroke volume (how much blood the heart expels with each beat), then the reduction is due to the arterial-venous oxygen difference.

Oxidative Capacity

One of the main characteristics of detraining is the reduction of the oxidative capacity of the muscle, due to a reduction in enzymatic activities and in the production of ATP (our "fuel"). These were mainly observed after a two-week break from training, which would therefore seem to be the limit for maintaining most of the benefits acquired in the previous months of training.

As far as muscles are concerned, we have a study that shows a reduction in the transverse section of the calf by 7% after 3 weeks off; similarly another study shows a decline of 6.4% in 14 days. In this case, however, it was interesting to note an increase in growth hormone, testosterone and a decrease in cortisol. It would therefore appear that a short break from training has benefits from an Anatolian perspective.

In this sense, it is interesting to explore the "physical fatigue paradigm": after a brief suspension of training, the fatigue accumulated during the season can vanish, allowing the effects of previous training to come to the surface, even improving some qualities; this occurs above all for neuromuscular qualities, such as jumps, and as we have seen also for some biochemical parameters.