Resistance training (RT) and aerobic training (AT) both offer health benefits, but RT shines when the goal is sculpting body composition—meaning more muscle and less fat. While aerobic training reduces overall body weight and fat mass more than resistance training, RT increases lean muscle mass. In major randomized trials, RT alone didn’t always lead to impressive weight or fat loss, but did reliably boost strength and add muscle where AT did not. The unique appeal of RT is its impact on metabolism—muscle tissue burns more calories than fat, even at rest, supporting long-term fat loss. RT also enhances bone density, insulin sensitivity, and functional strength. Cardio excels for heart health and pure fat loss, but for the “jacked” look—visible muscle and athletic performance—you need RT as your foundation. The best routine combines both, but prioritizes RT for total recomposition.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3544497/
https://inbodyusa.com/blogs/inbodyblog/cardio-vs-weights-vs-concurrent-whats-better-for-body-comp/