Cardio vs. Strength: You Need Both
Definition
Cardio and strength training are complementary forms of exercise that produce distinct, non-overlapping health benefits. Cardio (aerobic exercise) improves cardiovascular fitness and longevity. Strength training (resistance exercise) builds muscle mass, protects metabolism, and maintains functional independence with age. Both are required for optimal health: neither can replace the other.
When This Applies
- You’re designing a training program and wondering how to split your time
- You’ve heard that cardio “kills gains” or that lifting is unnecessary
- You want to understand the minimum effective dose for both modalities
- You’re optimizing for longevity and functional health, not just aesthetics
The Debate
Some fitness influencers insist cardio is pointless: “just lift faster.” They warn that steady-state cardio “kills gains” and wastes time (Schoenfeld & Grgic, 2021).
They’re wrong.
What The Evidence Says
Both forms of exercise provide benefits the other can’t replace:
- Cardio keeps you alive longer. Each 1-MET increase in fitness cuts mortality 10–17% (Blair et al., 1996; Mandsager et al., 2018).
- Strength keeps you functional. Muscle mass protects metabolism, mobility, and independence as you age (Attia, 2023).
- Guidelines exist for a reason. 150 min/week moderate cardio + 2 days strength training (American Heart Association, 2018).
Cardio and strength aren’t competing. They’re complementary.
The Practical Split
- 2–3 lifting sessions per week
- ~150 minutes Zone 2 cardio spread across 3+ sessions
Cardio won’t ruin your gains if you program intelligently (Schoenfeld & Grgic, 2021). It actually enhances recovery and fat oxidation. Strength training protects the muscle that cardio alone won’t build (Lyon, 2023).
Pick both. That’s the 80/20.
Related
- Strength Training Protocol : The resistance training protocol
- Zone 2 Cardio Protocol : The aerobic training protocol
- Sleep Architecture : Recovery enables adaptation from both modalities