The best athletes in the world are committed to a training program that enhances their physical skills. However, working out every day often doesn’t necessarily always lead to better results. It’s just as important to give your body time to recover as it is to perform intense training sessions. That’s right…taking days off can actually improve your results.

Here are five reasons why you shouldn’t necessarily be working out every day.

Replenish Energy Stores

Your body uses adenosine triphosphate (ATP) to power muscle contractions. During weight training, the most readily available source of this energy is muscle glycogen. This source is finite, so it must be replenished before another training session. If you work out on low energy stores, you will notice decreased performance, because your muscles will be used as a source of energy and begin to break down. (Learn how muscles work.)

Repair Muscle Fibers

A proper training program is designed to stress your muscles, which is the only way to stimulate gains. However, this stress causes damage to muscle fibers. The process of repairing this damage and rebuilding muscle tissue after a workout is actually when muscles get bigger and stronger.

Alleviate Muscle Soreness

Any time you challenge your muscles in a new way or increase your workout intensity, you will encounter sore muscles. Delayed-onset muscle soreness (DOMS), which occurs between 24 to 72 hours after a workout, can feel anywhere from mildly discomforting to nearly debilitating. DOMS is caused be microscopic tears in the connective tissue surrounding muscles. It will resolve itself, but it is a sign that your muscles need time to rest. (Alleviate muscle soreness with a foam roller.)

Avoid Overtraining

Athletes who train too frequently run the risk of overtraining, causing stress, exhaustion, fatigue, irritability, decreased performance and even injury. Your body transitions from a state of muscle building to muscle break down. In this case, too much of a good thing turns into a bad thing. (Learn more about overtraining.)

What to Do

Maximizing your training program is simple—you need to schedule recovery into your training.

As a general rule, allow a muscle group to rest for 48 hours before reworking it. For example, if you work your legs on a Monday, don’t rework them again until Wednesday.

To create an efficient schedule, stick to a split-routine plan. This commonly involves splitting your routines into upper- and lower-body days, but you can get more specific if you want.

One final note: instead of working out every day, you need to actually plan days to allow your body to rest, even if you aren’t reworking the same muscle groups. Plan a mid-week rest day, and then one or two days off on the weekend to allow your body to fully recover. Ideally, you should only work out between three and five days per week.