“Cardio is Killing Your Gains? Here’s What Mike Mentzer Believed”
When we think of bodybuilding, the mind often races to heavy weights, protein shakes, and muscle pumps. But what about cardio exercises? For decades, bodybuilders have debated the role of cardiovascular training. Should it be a part of your routine? If so, how much?
One voice that stood out in this debate was Mike Mentzer — a professional bodybuilder, philosopher, and the pioneer of High-Intensity Training (HIT). Mentzer had a very clear take on cardio for bodybuilders, and it might just surprise you.
What Did Mike Mentzer Say About Cardio exercises?
Mike Mentzer believed in training briefly, infrequently, and intensely. His approach was laser-focused on maximizing muscle hypertrophy without unnecessary volume or overtraining. When it came to cardio, Mentzer was skeptical, and here’s why:
“Too much aerobic activity can work against muscle building, especially when done excessively alongside intense resistance training.” – Mike Mentzer
He argued that excessive cardio could drain recovery resources, interfere with muscle repair, and even stimulate catabolism (muscle breakdown), especially for hardgainers or naturals not using anabolic aids.
Why Did He Recommend Limiting Cardio exercises?
- Recovery is Key:
In Mentzer’s philosophy, recovery equals growth. Cardio, particularly long-duration steady-state forms, takes up energy that your body needs to recover from intense weight training. - Counterproductive for Muscle Gain:
He believed that too much aerobic work could hinder anabolic (muscle-building) processes. For someone prioritizing muscle mass, that’s a clear red flag. - Training Efficiency:
Mentzer encouraged minimal training time with maximal effort. Spending hours doing cardio didn’t align with his principle of training economy.
Check out our article on Mike Mentzer’s advice for effective fat loss: https://anshfit.com/exercise-to-reduce-belly-fat/
So, Should Bodybuilders Avoid Cardio exercises Completely?
Not necessarily. Even Mentzer acknowledged the cardiovascular system’s importance for general health and suggested light cardio in moderation if needed. However, his advice was to keep it infrequent, short, and low-intensity — something that wouldn’t compromise your weight training recovery.
Cardio Guidelines Based on Mentzer’s Principles
If you’re following a HIT-inspired routine or simply want to prioritize muscle growth without sabotaging your gains, here are some cardio guidelines rooted in Mentzer’s philosophy:
1. Limit Frequency
- 1–2 sessions per week is enough for cardiovascular benefits without harming recovery.
2. Keep It Brief
- Sessions should be 20–30 minutes max, ideally on rest days, not training days.
3. Choose Low-Impact Cardio
- Walking, cycling, or slow jogging are ideal.
- Avoid high-intensity cardio or excessive HIIT if muscle gain is your goal.
4. Time It Right
- Do cardio after your weight training, not before.
- Even better: keep cardio and strength sessions on separate days.
Modern Takeaway: Finding Balance
While some modern athletes swear by fasted cardio or regular HIIT, Mentzer’s school of thought remains a valuable reminder: more is not always better.
For natural lifters especially, overdoing cardio can stall progress, impact hormones, and increase fatigue. Prioritize strength training, ensure full recovery, and view cardio as a health supplement — not a main course.
Final Thoughts
If you’re a bodybuilder or muscle-building enthusiast trying to maximize gains, take a page from Mike Mentzer’s playbook. Train hard, rest well, and keep cardio in check.
Let cardio serve your goals — not sabotage them.