Will Cardio Make My Muscle Fibers Shrink?
This morning, I got an e-mail from a reader. "I’m following the Maximum Muscle Plan 4-day routine," he asked. "I wanted to know how to incorporate cardio in the program. Also, I read an article saying that running shrinks your muscle fibers - is that just in the leg area, or is it throughout the whole body?"
To answer the second part of your question first, it really depends on the amount of running you're doing.
Running long distances 3-6 days per week is a step in the wrong direction if you're trying to gain muscle. But in general, aerobic exercise — as long as you don't do too much of it — does not interfere with gains in muscle size.
Unless you're someone who really struggles to gain muscle, and provided that calorie intake is sufficient, the addition of 1-2 hours of moderate-intensity aerobic exercise (such as cycling at 60-80% of your age-derived maximum heart rate) to a weight-training program won’t make your muscle fibers shrink.
In fact, several studies show that it may actually help a little with muscle growth (see Does Aerobic Exercise Really Slow Down Muscle Growth?).
As for how to incorporate cardio in the 4-day routine, I’d suggest doing it on your “off” days. For example:
Monday: Lower Body
Tuesday: Upper Body
Wednesday: Cardio
Thursday: Lower Body
Friday: Upper Body
Saturday: Cardio
Sunday: Off
If you want to do cardio after you lift weights, I’d recommend doing it after the upper body workouts. My legs are usually trashed after training my lower body and the last thing I want to do is spend 30-40 minutes on the treadmill.
Because of its potential to interfere with recovery, I'd steer clear of any high intensity interval training and stick with steady-state cardiovascular exercise.
About The Author
Christian Finn holds a master's degree in exercise science, is a certified personal trainer and has been featured on BBC TV and radio, as well as in Men's Health, Men's Fitness, Muscle & Fitness, Fit Pro, Zest and other popular fitness magazines.
If you're stuck
in a rut with your current exercise and diet plan... fed up with
only losing a pound here and there... or still skinny after months
(or even years) of trying to build muscle and gain weight... click here now for instant access to his step-by-step muscle-building and fat-burning workout routines.
Related Articles
|