Should You Do Cardio Before or After Weights to Build Muscle? We Asked the Experts

Strength training, sometimes known as resistance training or lifting weights, is one of the best ways to build your muscles and keep them healthy.

Keeping your muscles strong is especially important as you get older, as the decreased energy levels and frailty associated with age is largely due to the loss of muscle, which mainly results from inactivity.

Resistance training builds muscle and can also reduce the signs and symptoms of many diseases and chronic conditions including arthritis, diabetes, osteoporosis, heart disease, obesity and back pain.

Most people hitting the gym tend to fall into one of three camps—those focusing on a cardiovascular workout (aerobic activities that get your heart beating faster), those doing strength training and those there to do a bit of both.

"Strength training, when done with regular aerobic exercise, can also have a major effect on a person's mental and emotional health," says the U.S. Centers for Disease Control and Prevention (CDC).

But if you're looking to build muscle, should you do cardio before or after weights?

Cardio or Weight Training?

Speaking to Newsweek, Darien Bernard, a W.I.T.S. (World Instructor Training Schools) certified personal trainer at Crunch Fitness, said if your workout goal is to build muscle, you should do cardio exercises after weights.

Bernard explained: "In order to achieve maximum muscle gains, you need to have the energy and nutrient stores to put forth maximum effort in your weight training program.

"Doing cardio prior to weight training will decrease your ability to put maximal effort during weight training, as you will have fatigued your muscles from cardio," he added.

Speaking to Newsweek, Kyle Kercher, an exercise physiologist certified by the American College of Sports Medicine, also said to prioritize your strength training session if you're looking to build muscle, as building muscle is more associated with strength training rather than cardio exercises.

"You may be best served by strength training first as you're likely to have better energy compared to if you try to do it after a cardio session," he explained.

The certified exercise physiologist also said those who want "cardio benefits at the same time as strength gains," can consider combining the two exercises by "pushing the tempo of your weight training session so your heart rate stays high or rises and falls for the duration of the workout."

But if building muscle isn't the ultimate goal, Kercher said it comes down to a matter of preference and which routine suits you better.

He explained: "My main suggestion here is to go with what you prefer/enjoy more.

"Ultimately, when it comes to either cardio or strength training, the most effective program is one that you will stick with – so make it enjoyable to you," he said.

So if you enjoy doing strength training before cardio exercises and that's what you're more likely to stick with, then do it that way, Kercher said.

People lifting barbells at a gym.
A woman and a man doing dead lifts using barbells at a gym. Weight training sessions should be around 45 minutes to an hour long. iStock/Getty Images Plus

How Long Should My Cardio and Weight Sessions Be?

Bernard said weight training sessions should be around 45 minutes to an hour long, while the cardio session should be about 30 minutes long.

Kercher said: "Many people have a preconceived notion that both cardio and weight training sessions need to be relatively long," such as more than 30 to 60 minutes. "But you can get a lot done in a short time," he added.

When it comes to cardio sessions, "Go with what you enjoy and will be able to sustain for the long-term," he noted.

"Some people like short bouts," such as 10-15 minutes, whereas others like longer sessions, he explained.

A group of people running on treadmills.
A group of people running on treadmills. Doing cardio workouts before weight training will decrease your ability to put maximal effort into your strength training session. iStock/Getty Images Plus

What to Eat Before Your Cardio and Weight Sessions

You'll want to eat healthy carbohydrates and protein-rich foods at least one to two hours before your cardio and weight sessions, Bernard said.

"This can include protein smoothies, eggs with whole grain bagels, yogurt and fresh fruits, or bananas with toast and almond butter. This will give your body the nutrients and energy it needs to maximize effort during exercise," he explained.

Kercher also encourages eating and re-fueling "very soon" after your workout to provide your body with fuel to recover.

A group of people doing exercises using
A group of people doing exercises using weights. iStock/Getty Images Plus