A recent study published in the Journal of Exercise Science & Fitness finds that the order of workouts can affect fat loss. This research supports earlier findings about how exercise sequencing influences body composition.
Researchers studied 45 obese young men between 18 and 30 years old. They split the participants into three groups for 12 weeks. One group acted as a control and kept their usual lifestyle without changing their exercise habits.
The other two groups exercised for 60 minutes, three times per week. Both groups followed the same training program, but the order of exercises was different. One group did weight training first, then cardio. The other group did cardio first, then weight training. To track daily activity accurately, participants wore sports watches. This method helped avoid unreliable self-reports, according to Science Alert.
The strength training included bench presses, deadlifts, bicep curls, and squats using real weights. The cardio workouts involved 30 minutes on a stationary bike. Both groups improved in cardiorespiratory endurance, cardiovascular fitness, muscle strength, and body composition.
However, differences appeared in fat loss and muscle performance depending on exercise order. Those who lifted weights before cardio lost more total body fat. They also reduced visceral fat, which is linked to higher risk of heart disease.
The weight-first group became more active during the day. They increased their daily steps by about 3,500, compared to only about 1,600 extra steps in the cardio-first group, Science Alert reported.
The reason behind these results relates to how the body uses energy. Weight training uses up muscle glycogen, a quick source of fuel. When participants did weights first, their glycogen stores were depleted. This forced their bodies to switch to burning fat for energy, explains Science Alert. This shift helps explain the greater fat loss seen in the weight-first group.
For years, fitness experts have debated whether cardio should come before or after lifting weights. Until now, the choice was mostly personal preference. Some people warm up with jogging before weights, others run after. But this new evidence shows starting with weights is better for burning fat. Those who lifted first lost more fat than those who did cardio first.
Both groups improved their cardiovascular fitness similarly, no matter the exercise order. So, if your main goal is aerobic fitness, the order matters less. But if fat loss and daily activity are the focus, starting with weight training works best.
Doing cardio first may weaken the effectiveness of weight training. Cardio tires muscles by using glycogen, leaving less energy for lifting weights. “Cardio causes fatigue and may reduce muscles’ strength and power,” notes Science Alert. A recent review supports this, showing that explosive strength gains may drop if cardio is done before strength training in the same session.
The study had some limits. It only included obese young men. It did not consider diet, sleep, or stress, which can affect body changes. Also, 12 weeks may be too short to see long-term effects. Future studies should include these factors for clearer advice.
Still, the findings match other research on combined training. A review found that starting with resistance training leads to better strength gains than starting with endurance exercises. The American Heart Association’s 2023 statement confirms resistance training increases lean body mass and lowers fat, especially when paired with other exercises.
Both cardio and weight training improve health. This shows why both should be part of any fitness routine. “Whether you do cardio before or after weights, both improve overall health,” says O Globo. But for those aiming to lose fat and boost daily activity, evidence favors doing weights first.
