Several other studies, such as those conducted by researchers from the Children’s National Medical Center, the Waikato Institute of Technology, and the University of Jyvaskyla in Finland, came to the same conclusions: training for both endurance and strength simultaneously impairs your gains on both fronts.32 Training purely for strength or purely for endurance in a workout is far superior. Cardio before weightlifting also saps your energy and makes it much harder to train heavy, which in turn inhibits your muscle growth.
