If you want to build muscle, don't do cardio before weights. Here's why

An expert personal trainer explains why it's better to leave cardio until after resistance training to maximize muscle gain

Woman weight trains before she doing cardio
(Image credit: Getty)

The topic of whether or not you should do cardio before or after weight training is commonly discussed. It does depend on your fitness goals but, if you're looking at improving muscle mass, your weight training sessions can greatly benefit from leaving cardio until after you're done in the squat rack.

You don't necessarily need to learn how to lift weights in the gym: home gym setups became super popular over the pandemic, meaning people could train with weights in their garage using equipment like a set of the best adjustable dumbbells. Plus, you can even use your own body weight to build muscle and improve strength, with pull-ups, push-ups, air squats and more. However, in the gym, it's pretty common to see people warm up with a cardio session before hitting the weights.

If growing muscle strength and mass is a goal of yours, then the following advice from personal trainer Scott Laidler (opens in new tab) might have you rethinking your cardio/resistance training split. Laidler has worked in the industry for over 12 years, delivering a total of 10,000 hours of one-to-one personal training sessions. He shared the key to enhancing your results.

"Generally speaking, it would be most effective to do cardio after your main workout, because you want to allocate the majority of resources to the more demanding workout. This is for both performance and safety reasons, for example, you wouldn't necessarily want to run hills then try to hit a PB on your barbell squat," he explained.

Outdoor cardio session

(Image credit: Getty)

This study published in The Journal of Strength and Conditioning Research (opens in new tab) backs up what Laidler said. Research scientists discovered that running or cycling before a weight training session limited the number of reps the participants could perform compared to when they hit the smith machine without having run or cycled beforehand.

Conserving as much energy as possible prior to strength training is a wise plan but Laidler said this doesn't mean you shouldn't do anything at all before lifting weight.

He noted, "Actually, you want to do a dynamic warmup, which takes you through the gears and gets the body warmed up and progressively exposed to the movements that you will be doing under more demand in the actual workouts. So whilst this pre-workout activity might technically be cardiovascular in nature by heart rate, the intention is to enhance performance in the main workout, rather than supersede it."

Examples of dynamic movements suitable for a warm-up could look like some lunges or squats without weights, leg swings, arm circles, or knee cradles. Warming up is important for avoiding injury. If you do suffer from any pains from exercise you may benefit from taking one of the best supplements for joints, unless your doctor advises otherwise.

It is also important to note that cardio isn't to be avoided like the plague when improving strength and muscle. Want bigger quads? HIIT-style running can help improve leg muscle according to research (opens in new tab), and this interval training can be performed on one of our best treadmills from our roundup. You can even do shuttle-sprints outdoors if you prefer getting into nature for your cardio.

Jessica Downey
Staff Writer

Jessica is Staff Writer at Fit&Well. Her career in journalism began in local news and she holds a Masters in journalism. Jessica has previously written for Runners World, penning news and features on fitness, sportswear and nutrition. 


When she isn't writing up news and features for Fit&Well covering topics ranging from muscle building, to yoga, to female health and so on, she will be outdoors somewhere, testing out the latest fitness equipment and accessories to help others find top products for their own fitness journeys. Her testing pairs up nicely with her love for running. She recently branched out to running 10Ks and is trying to improve her time before moving on to larger races. Jessica also enjoys building on her strength in the gym and is a believer in health and wellness beginning in the kitchen. She shares all of this on her running Instagram account @jessrunshere which she uses for accountability and for connecting with like-minded fitness lovers.