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Strength and power are gained when the body is at rest. After putting the body under high levels of stress by lifting weights, pounding the pavement, or cranking out burpees, optimal progress occurs during the body’s recovery time. Many avid exercisers think of recovery days as lazy or as requiring complete stillness. While stillness can definitely be beneficial at times, ACE Fitness defines a rest day as “any non-training day—a day where you remove the challenge of hard exercise.”
Why do I need rest days?
Recovering from a workout is just as important as the workout itself for a variety of reasons. The physical stress of exercise breaks down muscle fibers (think microtears), depletes stored carbohydrates (glycogen) that fuel movement, challenges the central nervous system, and temporarily increases inflammation as part of the body’s natural healing process.
The recovery period starts the moment the workout ends, but a full, quality rest day allows the body time to:
- Refuel and properly restore energy sources in the muscles to prepare for your next hard workout.
- Repair the torn muscle fibers, which help them grow stronger.
- Rehydrate and restore lost electrolytes.
- Get better sleep by preventing overtraining. Deep sleep produces growth hormones that help the body heal and repair itself.
- Remove toxins and byproducts that cause muscle soreness.
- Increase blood circulation throughout the body to deliver the nutrients necessary for muscle tissue to recover.
- Experience self-care and stillness that improves emotional and physical health.
What’s Happening Inside Your Body on a Rest Day?
It may feel like your body is “doing nothing” on a rest day, but behind the scenes it’s actually working hard.
About 60–75% of the calories you burn each day come from your resting metabolic rate (RMR): the energy your body uses simply to keep you alive. Your heart continues beating, your lungs continue breathing, your brain remains active, and every cell in your body is constantly working to maintain normal function.
After a challenging workout, your body shifts many of those resources toward recovery. Energy is used to repair damaged muscle fibers, replenish glycogen stores, restore fluid and electrolyte balance, reduce inflammation, and help your nervous system return to normal.
Your metabolism also remains elevated after exercise through a process called excess post-exercise oxygen consumption (EPOC), often referred to as the “afterburn effect.” During this time, your body continues using oxygen and energy to restore normal body temperature, hormone levels, oxygen stores, and cellular function. Depending on the intensity of your workout, this process can continue for several hours after exercise.
Think of it this way: your workout provides the stimulus for change, but your rest day provides the opportunity for adaptation. Without enough recovery time, your body spends more time repairing damage than building strength, making it harder to improve performance over time.
Workout → Recovery → Adaptation
Exercise
↓
Microtears in muscle fibers
↓
Inflammation & energy depletion
↓
Rest day
↓
✓ Muscle protein synthesis
✓ Glycogen replenishment
✓ Nervous system recovery
✓ Hormone regulation
✓ Tissue repair
↓
Stronger muscles & improved performance
What Counts as a Rest Day?
A rest day doesn’t always mean spending the entire day on the couch (unless that’s exactly what your body needs).
There are two types of recovery:
Passive recovery involves taking a complete break from structured exercise. This is often the best option after an especially intense workout, race, or when you’re feeling physically or mentally drained.
Active recovery involves gentle, low-intensity movement that promotes healing without placing additional stress on the body. Activities like walking, stretching, yoga, swimming, or an easy bike ride can improve blood flow, reduce stiffness, and help you feel refreshed. The key is to keep the intensity low—you should finish feeling better than when you started.
Whether you choose passive or active recovery, the goal is the same: give your body the time and resources it needs to repair, recharge, and prepare for your next workout.
What happens if I don’t rest?
Without rest days, your body may show signs of overtraining, ultimately leaving you feeling burnt out.
Your muscles may not see the gains you think they should if you don’t give them enough time to recover.
If you experience any of the signs or symptoms below, you most likely need a couple of rest days:
- Frequent injuries
- Muscle pain or soreness that lasts several days
- Trouble sleeping even though you feel exhausted
- Poor immunity causing frequent illness
- Irritability and mood swings
- Low motivation and productivity
- Mental fatigue and trouble concentrating
- Inability to manage or handle stress
- Decreased desire to do things you enjoy, including your workout
How often do I need to rest?
Listen to your body and decide when you need to take a rest day based on exercise type and intensity, age, and training experience. The greater the intensity or impact of the exercise, the more rest the body typically needs. Understand your exercise threshold so as not to push yourself so hard that you’re left crawling on the floor for the next five days. A proper workout usually needs 1-2 days of recovery with at least one rest day before working the same muscle group(s) again. If you’re still sore after two days, you may want to rethink your workout and/or recovery plan.
Remember that recovery is highly individual. Two people can complete the exact same workout but require different amounts of recovery. Learning to recognize your body’s signals is one of the best ways to avoid injury, improve performance, and continue making progress.
Actionable Steps
- Want to read more? Check out our articles page for more fitness and health-related topics, including: Should I Be Taking Supplements?, Lifestyle Habits For Better Sleep, Going Out Of Town Without Going Out Of Shape, and Eating To Boost Your Immune System.
- Plan your rest days: Depending on the demands of your work, social, and exercise routines, you might do better with scheduled rest days. If you’re more of a recreational exerciser, you might be able to go with the flow and take rest days when your body tells you. You do you!
- Recognize the signs of overtraining: …and make sure you listen to any signs that come up. Adjust your rest days accordingly. Everyone’s body reacts to stress differently, so individualize your training plan.
- Keep it simple: You can do low-impact movements like light stretching, gentle yoga, or go for a casual walk. Foster your mental health by letting your mind relax today. Give those deep muscle tissues a little extra TLC. Learn more about how to have a quality rest day with these tips from ACE Fitness.
- Refuel and rehydrate: Continue eating well-balanced meals with quality protein and replenish lost fluids throughout the day.
- Be productive: Got some extra time during your rest day? Spend that quality time with friends or family, learn a new hobby or skill, catch up on a great book, or do some light household chores. Read more on how to be productive here.
Sources
- https://www.acefitness.org/education-and-resources/professional/expert-articles/3565/exercise-and-rest-how-much-rest-you-actually-need
- https://www.acefitness.org/education-and-resources/professional/expert-articles/5411/10-things-to-know-about-muscle-fibers
- https://pubmed.ncbi.nlm.nih.gov/14692598/
- https://pubmed.ncbi.nlm.nih.gov/7874151/
- https://pubmed.ncbi.nlm.nih.gov/7874151/
- https://www.acefitness.org/resources/pros/expert-articles/5456/passive-vs-active-recovery-which-is-more-effective/?srsltid=AfmBOopAuaZOK5dDdVFbAlCoBIc-ZyzOsyAVDoKTpJPuIr0w6llqld2e
- https://www.acefitness.org/education-and-resources/professional/expert-articles/3565/exercise-and-rest-how-much-rest-you-actually-need
This article was originally written by Shannon Costello, Inc. and was updated for use by Meakin Metabolic Care by Aubrey Christofferson.
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