Moderate evidence

Doing cardio alongside lifting doesn't compromise muscle size or maximal strength.

In practice

You can train for your heart and your legs in the same week. Explosive, jumping-type strength is the one quality that may suffer, so if that's what you're training for, keep hard cardio away from those sessions.

What it doesn't say

This is about compatibility, not free lunch — a very large amount of hard endurance work still competes for the recovery your lifting needs.

Source

• Schumann M, Feuerbacher JF, Sünkeler M, Freitag N, Rønnestad BR, Doma K, Lundberg TR (2022). Compatibility of concurrent aerobic and strength training for skeletal muscle size and function: an updated systematic review and meta-analysis. Sports Medicine, 52(3):601–612. doi.org/10.1007/s40279-021-01587-7