Your body is a finely tuned machine equipped to survive and adapt, but like any other machine, it needs rest. Regular exercise elicits changes in your physiology that manifest themselves as gains in fitness and health. Rest is an important part of these changes. The time you take between workouts affords your body the opportunity to recover and adapt to the stimulus of exercise. For example, healing and replenishing lost enzymes and fuel storage takes place during rest. Aerobic exercise can be daily, but your muscles need a break after resistance training. Overtraining, or too much exercise without enough rest, can be detrimental to your goals and your health.
Aerobic Exercise
Aerobic exercise is a sustainable form of activity that requires more energy than when you are at rest. It trains your muscles and cardiovascular system in an endurance-type manner, and is less stressful to your body than other forms of exercise. For this reason, you can participate in aerobic exercise daily. Your workout sessions can be planned with rest that extends from day to day. In fact, this is highly recommended. According to the American College of Sports Medicine, you should participate in 30 minutes of aerobic exercise on most, if not all, days.
Resistance Exercise
Resistance exercise uses progressive force production to stimulate your muscles to grow in size and strength. To make this adaptation you must break down your muscles to build them up. Resistance exercise is stressful and thus requires rest between workouts. Depending on your training program, you should rest from 24 to 48 hours between workouts. A more stressful workout, and one that causes muscle soreness, warrants a longer rest period.
Rest
Rest is as important as training. The training stimulus signals to your body what changes need to be made to the muscles and cardiovascular system. However, it is during your rest period that the body can start making the changes necessary to adapt to your training. If you do not rest, your body can never adapt and you will plateau.
Overtraining
Working out without adequate rest can result in overtraining, which presents itself through your physical, emotional and behavioral health. Physically, overtraining will make you tired, limiting your training and even leading to injury. Emotionally and mentally, your mood is altered when you over-train. It can increase your cortisol levels, signaling extra stress to your body and mind. Avoid overtraining by getting adequate rest between workouts.
References
- "ACSM's Guidelines for Exercise Testing and Prescription"; Mitchell H. Whaley, PhD, et al.; 2006
- Rice University: The Overtraining System
- "Exercise Physiology: Human Bioenergetics and Its Applications"; George A. Brooks, et al.; 2005
