Exercise is a crucial part of a healthy lifestyle. We should be working out for at least 150 minutes per week at a moderate intensity, for 75 minutes per week at a higher intensity, or a mix of both, according to the current Physical Activity Guidelines for Americans.

How much of that should be dedicated to strengthening your upper body? Experts say there’s an optimal number of days.

Ensure you’re dedicating enough time to working out your back, shoulders, triceps and biceps with strength training movements that will both tone your upper body, and support your spine, neck and elbows along the way.

Trainer Tip of the Day: Train Upper Body Three Days a Week

Dedicate three training sessions a week to your upper body with rest days in betweem, Stephanie Mansour, TODAY fitness contributor and personal trainer, said on TODAY.com.

Why It Matters

Rest, like working out, is nonnegotiable.

A three-day upper body training schedule gives your upper body time to rest during the remaining four days in the week. The upper body consists of larger muscles, Mansour pointed out, and those muscles need time to recover.

“The larger muscles of the legs and glutes and the arms and back do require a rest day in order for them to recover and repair,” she said.

Muscle growth doesn’t only happen when you’re sweating, straining and pushing your muscles to their limits; it also happens in between your workout sessions. So, give your back and arms their much-deserved break in between exercises.

How to Get Started

If you’re not sure about where to start, Mansour created this sample strength training workout schedule that you can follow:

Monday, Wednesday, Friday: Lower body circuit + coreTuesday, Thursday and Saturday: Upper body circuit + coreSunday: Core

Feel free to tweak as needed. If instead of three upper-body-only sessions at the gym you’d prefer to combine them with other types of workouts and focus on other muscle groups, too, go right ahead. Just make sure you pencil in enough time for rest.

Download the Start TODAY app for more workout plans featuring Mansour and other best-in-class trainers.

TODAY’s Expert Tip of the Day series is all about simple strategies to make life a little easier. Every Monday through Friday, different qualified experts share their best advice on diet, fitness, heart health, mental wellness and more.