… And he rested on the seventh day from all his work which he had made (Genesis 2:2)

Today is a fairly significant holiday in the US and many other predominantly Judeo-Christian countries. It is Easter Sunday (as well as the second day of Passover), which means that many businesses are closed or open only limited hours today. That is true of my gym, which opened at 7AM but closed at 2PM.

But while many might bemoan that fact that the gym closed early – as well as the fact that most of the training classes normally offered on Sunday were cancelled – it doesn’t really matter to me. That is because for me most Sundays are active rest days. This is not for any religious reason, but rather because taking rest days is incredibly important to any health and wellness program.

In my case, I work out an average of six to seven times a week. I usually split those workouts up between four hour-long strength-training sessions, two shorter sprint or cardio sessions, and one yoga or stretching session of varying length. But I always make sure to take one day off from the gym every week. Sometimes I even take two, should I find my energy or motivation to exercise is lacking.

So why is it so important to rest?

1. Rest is essential for recovery.

Quite simply, rest days are physically necessary so allow our muscles to repair, rebuild and strengthen themselves.

When we workout, we cause microscopic tears in our muscle tissue. It is your body’s attempt to repairthis damage that leads to muscle growth and improvements in strength and stamina; the body is slowly remodeling the damaged muscles into larger and stronger versions that are better able to handle the stresses and strains of future workouts.

This process of recovery and remodeling takes time. In fact, after a particularly tough and targetedworkout (such as a chest day when you hit a new personal record on the bench press), most exercise physiologists recommend giving that muscle group at least two tothree days to properly recover.

Without giving your body enough time repair and replenish itself, overtraining syndrome – characterized by fatigue, muscle weakness, and decreased performance – is likely to result.

2. Rest helps prevent injury.

Taking rest days is also proven to reduce the likelihood of an exercise-related injury.This is not just because of the microscopic physical trauma to your muscle, tendons, and joints that exercise causes, but also because of the impact that over-frequent workouts can have psychologically.

When you don’t allow your body to recover from high-intensity exercise, mental fatigue can set in. Brain fog and mood shifts are just one more frequent symptom of overtraining, causing professional, amateur, and causal athletes to lose motivation and focus. This can lead to sloppy form while lifting weights, or lack of attention while engaging in cardio activities like running or martial arts, all of which is a recipe for disaster.

Without sufficient time to allow both your body and your mind to recover, the likelihood of injury skyrockets. Taking a day off will not only help your body heal and help you regain mental focus, but will also make you more enthusiastic and excited to return to your regular workout routine.

3. Rest prevents illness.

A healthy amount of exercise provides boost to your immune system, helping you fight off the myriad of disease-causing bacteria, viruses, parasites, mold that you encounter on a daily basis.

Overtraining, however, actually reduces immune function and makes you more susceptible to getting sick. This is because exercise cause significant changes in two key hormones: norepinephrine and cortisol.

When you workout, your body produces higher levels of these two so-called ‘stress hormones.’ That is usually a good thing; these hormones are part of the “fight-or-flight” response that gives you the energy and the strength to lift that barbell for one more rep, to row that extra kilometer on the NordicTrack, or outrun that hungry bear that you accidentally disturbed while hiking.

These same hormones also suppress your immune system. Normally, that exercise-associated dip in immune function is transitory. However, overtraining can cause the total number of functional immune cells in your body to decline over time. This might explain why studies have found that elite athletes are three times as likely as recreational athletes to acquire respiratory infections like the common cold or the flu during the winter. It may also explain why, when elite athletes do get sick, their symptoms tend to last longer and be more severe.

Rest is essential for avoiding illness and, when it happens, for bouncing back quickly.

These are just three of the many reasons why rest days are so important. But it is also essential to remember that rest days are not an excuse to sit on the couch binging watching Game of Thrones while scarfing down a pint of ice cream.

Depending on your current level of fitness, try for an “active” rest day. Take the dogs an extra long walk, go for a hike with your husband, go for a bike ride with your kids, or play some touch football with your kids at the park.

Get out and do something, just keep it light and keep it fun.