If you haven't eaten or have done a longer and / or more intense cardio workout, be sure to eat within 45 to 60 minutes to restore muscle glycogen. (healthline.com)
Not only does it put strain on your joints, but it also puts a strain on your heart, particularly if you haven't engaged in intense cardio workouts in the past. (womenshealthandfitness.com.au)
Each additional pound of muscle also causes you to burn more calories through your workouts, especially if you are doing intense cardio workouts. (muscleandbrawn.com)