A good night’s rest, in the form of a deep and relaxing sleep, is essential to help the body recover from the stress of the day and prepare it for the rigors of tomorrow. If you regularly engage in strenuous exercise, this sleep time is even more important, both to help your body recover and to help it perform at optimal levels during exercise.

The physical stress experienced during exercise depletes the body of protein, water, and other essential nutrients. These can be recovered a bit by consuming protein and ensuring proper hydration after each exercise routine. The stress of exercise and emotional stress also increase the demand for certain hormones in the body. Chief among them is cortisol, which is released by the adrenal glands in response to stress.

Elevated cortisol levels are necessary for immediate “fight or flight” situations that can be quickly resolved, allowing the body to relax and return to normal. Regular strenuous exercise, combined with stressful modern lifestyles, can keep cortisol levels elevated well beyond what is required for an immediate threat. Cortisol pumps glucose into the body to help prepare muscles to respond to stressful situations. A consistently high level of cortisol raises blood sugar levels and can interfere with the immune system.

Managing and reducing stress is important to repair the damage and restore hormonal balance in the body. Deep, restful sleep helps the body restore its hormonal balance, allowing the recovery process to occur. In fact, the building of muscle, tissue, and endurance that you hope to gain from exercise takes place while you sleep. Exercise depletes resources and the body replenishes them when we are at rest.

Depriving yourself of sleep also deprives your body of vital time to repair and rebuild itself. The result can be lower performance. Repeated stressful exercise without recovery weakens the body over time. Studies show that sleep-deprived athletes have considerably lower muscle power. This effect appears to be increased for people who got up early, compared to those who went to bed late. Getting up at 4:30 a.m. may seem like a good time to train, but it can come at the expense of your performance and development.

Of course, a good diet is also essential for good physical performance. Choose foods rich in nutrition and protein that supply the essential elements your body needs to repair and rebuild muscle and tissue. Good nutrition also helps rebalance cortisol and other hormones. The combination of good nutrition and good sleep is the key to optimal performance, in exercise and in daily life.

Lastly, drink plenty of water. If you exercise regularly, you need to stay hydrated, and not just when you exercise. Caffeine is a natural diuretic, so drinking two large cups of Seattle’s Best in the morning will set you up for dehydration by the time you need to work out. Drinking water will not help you replenish the water you have already lost. The specific amount of water you need to drink each day depends on many variables, including your size and activity levels. Not drinking water regularly will increase the stress on your body.