If you do supervised strength training for over 10 weeks while losing weight, you can gain about 3 kg of muscle and get 25% stronger — and it’s the best way to keep or build muscle compared to other...

If adults do guided strength training for over 10 weeks, they might gain around 3 kilograms of muscle and get 25% stronger — and this could help balance out muscle loss from weight-loss drugs.

Doing strength exercises like lifting weights while losing weight helps keep your muscles and bones strong, unlike just walking or cycling, which can make you lose more muscle and bone.

Over a 10-week period, two different types of resistance training—short, intense sessions and longer, traditional sessions—did not lead to measurable changes in overall muscle mass, fat mass, or body fat percentage in healthy young adults. Small trends suggested the intense training might be slightly better for building muscle and reducing fat, but these trends were not statistically significant.

If healthy guys between 18 and 40 lift weights regularly for at least two weeks up to a year, they typically gain about 1.5 kilograms of muscle—no matter what kind of weight routine they follow.

Working out with weights twice a week for four months can help middle-aged Japanese women build a little more muscle, even as they get older.