New research shows weight training before cardio maximises fat loss and muscle strength gains.

For years, many fitness enthusiasts—including myself—have started workouts with cardio, believing it was the best way to warm up and get the blood flowing. Yet a fresh study now challenges this approach, revealing that the order in which you combine cardio and weight training could significantly impact your results.

Published in the Journal of Exercise Science and Fitness, this 12-week study divided participants into three groups: those who did weight training followed by cardio, those who did cardio before weights, and a control group who did no exercise at all. The study focused on men aged 18 to 30, a relatively narrow demographic, but the findings offer clear guidance on optimising workout routines.

Both exercising groups improved in physical activity levels, body composition, bone density, and muscle strength—proving that mixing cardio and strength training does deliver benefits. But the group who lifted weights before moving on to cardio showed the most “remarkable progress.” They experienced greater reductions in fat mass, enhanced markers of fitness such as explosive strength, and an increase in their overall exercise frequency.

Why does this order work better? It comes down to energy and fatigue. Cardio is taxing on muscles, and if done first, it can sap the strength and stamina needed for effective weight training. When muscles are fatigued from a hard cardio session, they simply cannot perform as well during strength exercises, which reduces muscle gains and may hinder fat loss efforts.

These results find support in another study published in the Journal of Strength and Conditioning Research, which found that doing anaerobic exercises—short, intense bursts of activity like sprints or high-intensity cardio—before weight training “impairs” the latter by limiting endurance and overall performance.

Practically, this means that if you want to build strength and shed fat, starting with your dumbbells, kettlebells, or barbell exercises before moving on to the treadmill or a run could be the smarter way to train. Not only does it help preserve muscle strength, but it also encourages more frequent and effective workouts.

It’s important to note the study’s limitations: its small sample size and focus on young men mean the findings might not apply universally. However, the underlying principle of prioritising strength training before cardio aligns with well-established exercise science on energy systems and muscle fatigue.

For those looking to maximise results, it’s worth reconsidering workout order. Doing cardio after weights allows you to push harder during strength training, making the most of your muscle-building efforts, while still enjoying the cardiovascular benefits afterwards.

So next time you lace up your trainers, consider switching things up. Your gains—and your body—might thank you for it.