Why rest days improve performance
It can be hard to STOP exercise and allow the body to recover when training for a race or physical goal. Rest and recovery days are just as important as training days. Rest days should be put in the schedule just like speed and hill days, tempo running days and long run days. A recovery phase allows the body to repair and strengthen itself so that it can deal with greater amounts of stress. To understand recovery and feel good about yourself while not exercising I find it is easier to focus on the changes that are occurring physiologically in the body. This stops the guilty feeling that so many runners feel when training.
While exercising the body uses energy stores in the muscle (muscle glycogen) to contract the muscles. While recovering or having a day off, it allows the muscle to restore its levels of glycogen so the next time you go out the muscle has energy to work.
The muscle cells of the heart, organs, and musculoskeletal system containing contractile filaments must change in size to produce greater force or stronger contractions. To meet the requirements of the increased force excerpted upon the bones from the muscles, and increased amounts of impact placed upon the bones from strenuous movements, the skeletal structure must increase its density and strength. Also the nervous system must undergo neural development to assume great muscle control, greater ability to recruit more muscle fibres per contraction and ability to perform these contractions more frequently. Finally, the neuroendocrine system responsible for releasing hormones must increase in activity to enable all these physiological changes to occur.
Regardless of whether you exercise or not, your body is constantly undergoing physiological changes. Cells in your body are continuously being born. Infact, a few years from now, every single cell in your body, as in everything you physically are today, will be gone and replaced by new cells. So in effect you will literally be a completely new person. Who that person will be physiologically is completely dependant upon how you nurture those new born cells.
The stress and load paced upon the body causes the frameworks of the muscle fibers to become damaged. Once the attack is over the body gets the opportunity to rebuild, the body builds all the frameworks stronger and resilient in order to cope better with probable future attacks. This opportunity to rebuild comes when the body is at rest.
There is more to the answer of rest and recovery than time. The body’s rebuilding processes are dependant on so many factors such as: Nutrition, Hydration, Active Recovery, Hot and cold application and compression. Different types of recovery are possible.
Short term or active recovery occurs in the form of light intensity, short duration exercise after hard workouts and cool-downs. This is EASY exercise.
Long term recovery is the rest that is required of the body during an annual training schedule. This could be a period of cross training, training a different system and or a break from your usual sport.