This trend has been around for years but it dropped to No. 4 in 2015 and 2016 from No. 2. The ACSM study says that many young people train exclusively using weights to improve and maintain strength. Weight lifting is now incorporated in workouts for kids and patients with chronic illnesses as well. Another workout that has been around forever is strength training. No one really gets away with not building muscle. Without it it’s impossible to lose weight and stay fit. Strength training increases your metabolism, balance, and bone density, which is crucial as we get older.