Too Much Cardio
No one’s suggesting you give up your running routine altogether, but if you’re splitting your gym sessions equally between strength training and cardio, you’re sending your body conflicting signals. “We are adaptation machines, which means our body gets better at anything it does on the reg,” says Rob Sulaver, Founder and CEO of Bandana Training and Founding Trainer of Rumble. “Generally speaking, when you do a lot of cardio, your muscles get smaller and more efficient, and when you do a lot of strength training, your muscles get bigger and more powerful.”
Of course, this is a simplified explanation for how the body adapts to exercise, and Sulaver is quick to point out that cardio isn't the enemy of muscle. But if you’re struggling to put on mass, you have to adjust your routine to include more anabolic, or muscle-building, activities. Sulaver suggests switching out your long runs for alactic intervals, such as med-ball slams, battle ropes, or short sprints with 10 to 15 seconds of work and 60 to 90 seconds rest.