According to the American College of Sports Medicine, one of the principal fitness trends involves nothing more than your own body weight.

ACSM asked 3,346 corporate, clinical, community, commercial and academic health and fitness experts to answer the question, what is likely to make up the most popular fitness trends in 2013. The participants discussed emerging trends and whether or not last years’ trendy programs continued to be appealing. The survey listed 37 possible choices and the specialists rated the top 20.

This year’s ‘it’ fitness programs include a blend of new ways to sweat it out as well as some previous fitness regimens. Body weight training, a technique that uses your body’s weight as the foundation of resistance for strength training and muscle endurance. Spinning and Pilates, however, were less popular.