23-05-2025
This Type Of Workout Builds Muscle And Burns Fat In Less Time, New Study Shows
Think you always need long, slow strength sessions to build strength and burn fat? Think again. New research suggests that high-intensity circuit training—workouts that pack multiple strength moves into shorter sessions with less rest time—can deliver similar gains in strength, muscle, and fat loss as traditional weight training.
Led by Sohee Carpenter (a Women's Health cover star!), PhDc, CSCS, the new study offers useful takeaways for anyone short on time or craving variety in their routine. Here's what the research uncovered, and what a trainer wants you to know before switching things up.
Meet the expert: Albert Matheny, RD, CSCS, co-founder of SoHo Strength Lab
The study, which was published in the European Journal of Sport Science, followed 14 active women in their 20s and 30s as they either did high-intensity circuit training or traditional strength training three days a week for eight weeks.
Both groups performed the same six exercises: leg press, dumbbell bench press, trap bar deadlift, lat pulldown, hip thrust, and standing dumbbell shoulder press. But the high-intensity circuit training group performed the first three exercises in a time-based circuit fashion with minimal rest, followed by five minutes of rest before doing the same thing with the last three exercises. The strength training group did the same six moves—but did one exercise at a time in order and rested for three minutes between sets.
Both groups did three sets of eight to 15 reps, pushing their sets close to muscle failure. (That piece is key!)
The researchers took various body measurements before and after the study intervention and found that both groups increased their three-repetition maximum (a common measure of muscular strength, looking at the maximum weight a person can lift for three reps with proper form). Both groups also lost similar amounts of body fat and gained comparable lean body mass (muscle).
'Both high-intensity circuit training and traditional strength training are similarly effective for increasing strength and lean body mass and decreasing body fat percentage in trained women,' the researchers concluded. 'Those interested in maximizing time efficiency may prefer high intensity circuit training, as these sessions took much less time to complete.'
In an Instagram video breaking down her findings, Carpenter said: 'Many of us have been taught that circuit training is not nearly as effective for strength and body composition, yet we did not find that to be the case.'
The researchers stressed in the study that both groups pushed themselves to 'near-muscular failure.' But what does that mean exactly?
You get to the point in your reps where you're close to not being able to do another rep with the proper form, explains Albert Matheny, RD, CSCS, co-founder of SoHo Strength Lab, who was not affiliated with the study. 'The reason you have to push your muscles this way is because you have to create an adaptation,' he says. 'It only occurs if you push beyond a certain point. Pushing near your max is telling your body it needs to adapt and to get stronger and more efficient.'
You'll usually feel a tight or burning feeling in your muscles when this happens, along with trouble moving at the same rate or with the same amount of strength, Matheny explains.
You actually don't need to (and shouldn't necessarily) choose between the two. As the study found, both can lead to similar results. But, if you're looking to speed up your gym sessions, keeping the time period short between sets can cause you to get the same muscle gains as if you were to chill out for a bit between them.
That being said, Matheny would still recommend 'aiming for a mix.' Why? To allow for plenty of recovery time on higher intensity days, to maintain variety in your routine, and to reap allllll the health benefits of both styles. 'You can't do the fast moves all the time," he notes. But if you have only been doing traditional, slower-paced strength training, you can also benefit from high-intensity interval training (HIIT), he adds. "It can be very time efficient, and a good next step if you've already been doing strength training.'
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