What works better against belly fat: cardio or strength training?
Cardio beats strength training when looking purely at belly fat, but the combination of both performs best. Opt for high-intensity cardio or interval training, and add strength training if you also want to preserve your muscle mass.
High-intensity aerobic training and HIIT (interval training with alternating intensities) are the most effective forms of exercise against visceral fat, the dangerous belly fat surrounding the organs. In the largest overview of 84 studies, those two come out on top. Aerobic training at higher intensities reduces waist circumference by an average of 4.2 cm, compared with 2.5 cm at moderate intensity.
Strength training alone also has an effect, but a considerably smaller one than aerobic training or HIIT. There is an additional caveat: the effect of strength training appears to be present in men and in people with a body fat percentage below 40%, but is not demonstrable in women or in people with a higher body fat percentage.
The combination of cardio and strength training performs best of all in direct comparisons. In older adults with obesity, visceral fat fell by 36% with the combination, compared with 19% with cardio alone and 21% with strength training alone. Moreover, strength training improves muscle strength and metabolism in ways that cardio alone does not, which makes the combination even more attractive.
If you prefer to do just one thing: choose cardio at higher intensity or HIIT for the greatest effect on belly fat. If you also want to preserve or build muscle mass, add two to three strength training sessions per week. Nutrition also plays a role: in a comparative overview, calorie reduction had an even greater effect on visceral fat than exercise alone, although it is clear for exercise that more also yields more.
This answer is based on multiple overviews of randomised studies, including a network comparison of 84 such studies. The evidence for aerobic training and HIIT is strong and consistent. The evidence for strength training is somewhat less robust: the effect is not equally clear across all groups, and the researchers themselves note that this caveat applies to women and people with a high body fat percentage. The evidence for combined training also rests on direct comparative studies in humans, including older adults with obesity.
How much cardio do I really need per week?
For a healthy adult, 150 minutes of moderate cardio per week is the well-supported minimum, supplemented by two strength-training sessions; if you want to maintain your weight, you are better off aiming for 225-420 minutes per week.
Does strength training help with healthy ageing?
Strength training is one of the best-supported interventions for healthy ageing: training two to three times per week with progressive resistance demonstrably improves muscle strength, mobility and independence, even at an advanced age.
Is it better to take a cold bath before or after strength training?
Avoid taking a cold bath immediately AFTER strength training if muscle growth is your goal: it measurably inhibits muscle fibre hypertrophy. Schedule it before your training session, or use it on recovery days after endurance training.
How often and how hard should I strength train?
Start with 2 to 3 training days per week, sets of 8 to 12 repetitions close to your maximum, and increase the weight as soon as you can add extra repetitions. This approach demonstrably builds both strength and muscle mass at every level.
Does strength training work better against high blood sugar than cardio?
Strength training appears to work better than cardio alone in people with diabetes and a normal weight, but in overweight individuals that advantage is less clear and a combination of exercise with diet helps the most.
Does strength training help against bone loss (osteoporosis)?
Strength training helps to increase or maintain bone density, but the effect is modest and a reduction in fractures has not yet been demonstrated. Train at high intensity and under supervision for the best results.