7 Signs You Need a Rest Day

When your body needs a rest day, it speaks up.

It has to. After all, rest days give your body the time it needs to repair, heal and grow back stronger, explains Jessica Mazzucco, CPT, a certified personal trainer based in New York City. Without them (or enough of them) you interrupt your body's natural functions. Everything suffers.

So, how do you know if your body is craving a break? Watch out for these seven signs you need a rest day.

Delayed onset muscle soreness (DOMS), that light ache you get in the days immediately following a tough or new workout, is natural. But extreme soreness is one of the biggest signs you need a rest day.

Why? Because extreme soreness is a result of inflammation and tissue damage — things your body needs time to clear and repair. Plus, working out when you're super sore can make it difficult to maintain good exercise form, Mazzucco says. This can increase your risk of injury big time.

If you're so sore you're limping or wobbling, take an emergency day off. Try some light stretching or foam rolling.

Exercise is an effective mood-booster. But skip one too many rest days, and you'll likely experience the reverse.

That's because working out every day (granted you're hitting it relatively hard) can increase your body's levels of stress hormones including cortisol and epinephrine. This can lead to a hormonal imbalance and cause mood swings and irritability, according to the American Council on Exercise (ACE).

And if your head isn't in the game, you won't be able to give your full attention to your workout, resulting in a less-focused, less-productive sweat session — and possibly a greater chance of injury, Mazzucco says.

A surplus of stress hormones doesn't just mess with your mood. It can also keep your body keyed up and cause sleep problems, per the ACE.

And it's a vicious cycle. Sleep deprivation impairs your workout recovery, further upping your body's levels of inflammation and leading to even worse sleep and workouts, Mazzucco says.

No one feels psyched for every single workout. But if lately, your motivation and workout enjoyment have been in the pits, it might need to take it as a sign that you need a rest day, Mazzucco says.

The same hormones that can negatively affect your mood and sleep can also take their toll on your exercise outlook.

If your head isn't in the right place, try taking a rest day or active recovery day. Go for a short walk, stretch your muscles or straight-up lounge for a day. Do what feels good to both your body and mind.

If your easy runs suddenly feel like marathons, it's time to take a break.

Rate of perceived exertion (RPE), how hard an activity feels on a scale from 1 to 10, always goes up when you're lacking recovery. Your muscle strength and running pace also plummet, according to Mazzucco.

"A rest day can help you recharge, gain energy and perform your next workout to the best of your ability," she says.

If your heart racing during or (long) after your workouts? It could be a sign you need a rest day, Mazzucco says.

Here's why: The perception of a threat triggers a stress response from your nervous system, which then releases hormones that speed up your heart to move oxygen to your muscles and brain, she explains.

In other words, when you don't get enough rest, your body perceives it as a danger and puts you in constant fight-or-flight mode.

If you have a fitness tracker, keep an eye on both your resting heart rate and how long it takes your heart rate to recover after your workouts. If those numbers start rising, let up on the gas.

While HIIT workouts are time-efficient, torch calories and build muscle — it can take between 24 to 96 hours to fully recover from a strenuous session, per the ACE. So doing them every day can actually be detrimental to your body.

High-intensity training without sufficient recovery can even reduce immune system function, making you more vulnerable to infection, according to a May 2017 review in the ​​​​Journal of Applied Physiology​​​.​