When it comes to improving our physical fitness, the time you don't exercise is as important as the exercise and training you do.
Recovery is important for anyone who wants to build muscle mass, and taking enough time to recover between training sessions is also important for avoiding overtraining, a form of extreme fatigue where recovery can take weeks to years to occur.
When there is an unbalanced amount of exercise and recovery between sessions, it's called overtraining. It can cause an impaired immune response, altered hormonal activity and persistent fatigue.
Some reports and comments online suggest that overtraining may be a reason why some people are struggling to lose weight. This is not likely to be the case.
A "calorie deficit" is what you must create to lose weight. This means burning more calories than you are consuming, and over a sustained period of time.
Changing your diet or increasing the amount of exercise you do will both help you achieve a calories deficit.
If someone is overtraining then they will burn more calories than they are taking in, which will lead to weight loss. Some people think that overtraining would cause long-term stress to the body and lead to weight gain. This link usually involves a hormone called cortisol.
cortisol is released in response to stress, such as from work or school Cortisol is released when we exercise. The body does this in order to prepare for the stress it will experience, so it tells the body to release some energy to help complete whatever exercise we're doing.
Cortisol levels are usually back to normal within an hour after exercise. People who train frequently will experience elevated cortisol levels due to exercise related stress.
There is stress and weight.
The activation of the lipoprotein lipase is increased in fat cells when exposed to cortisol. Excess stress can sometimes lead to an increase in fat in the abdomen area, face and chest, because the cells are told to increase their storage of fats.
Increased cortisol levels can make it easier for fat tissue to grow again, which in turn increases the activity of lipoprotein lipase and subsequent fat storage.
There is evidence that overtraining affects the group of glands that make cortisol. The research shows that the cortisol response to stress decreases during overtraining.
The cortisol response to a high-intensity, 30-minute cycle exercise stress test is lowered after a short period of intensified exercise.
It has been found that periods of overtraining cortisol concentrations in our blood may be decreased in response to a stress event.
When the body is exposed to increased cortisol levels, this may be a protective mechanism. It is unlikely that a period of overtraining will increase fat storage.
There is a prevalence of overtraining.
It's hard to know what your risk is for overtraining if you exercise regularly. Studies show that between 30 percent and 60 percent of athletes experience overtraining due to their intense training demands. There is no research looking at how often the average person experiences overtraining.
People may be experiencing a weight loss plateau even if they exercise frequently. It's not likely that the average person who exercises a few times a week is going to experience a significant and sustained cortisol spike that will cause them to gain weight.
A number of factors can be to blame for the weight loss or weight gain that people are experiencing. Poor diet, overestimating the number of calories you're burning in the gym, and excess stress are some of the causes of poor diet and overestimating the number of calories you're burning in the gym.
If you've already lost some weight, but your progress has slowed, it may be worth calculating whether you need fewer calories. Adding in a lunchtime walk might help you burn calories without stressing your body.
It's important to schedule rest days into your exercise routine to avoid fatigue and allow your muscles to recover, even though it's unlikely that overtraining is preventing the average person from losing weight.
John is an Exercise Physiology lecturer at Trent University.
The Conversation's article is a Creative Commons licensed one. The original article can be found here.
