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When building a workout routine that combines cardio and strength training, one key question often arises: Should you run before or after your workout?
The answer isn’t as simple as one-size-fits-all. The best timing depends on your goals—whether you want to build muscle, lose fat, improve endurance, or simply boost overall fitness. Understanding the physiology of energy systems, muscle fatigue, and hormonal responses helps you choose the most effective order. Let’s explore the science so you can train smarter.
Understanding Concurrent Training
Concurrent training refers to combining aerobic (cardio) and anaerobic (strength) exercises within the same session or training program. While both forms of exercise offer substantial health and performance benefits, the order in which they’re performed can significantly impact adaptations like muscle growth, strength gains, and endurance.
Key Considerations
1. Your Primary Goal
- Fat Loss: Cardio after weights may be more effective for fat oxidation. Weightlifting depletes glycogen, encouraging the body to burn fat during the subsequent run.
- Muscle Gain (Hypertrophy): Cardio after is preferable. Doing cardio first can reduce strength, power output, and neuromuscular efficiency during resistance training, potentially blunting muscle gains.
- Endurance Performance: Cardio before may be appropriate for runners, triathletes, or cyclists focusing on endurance development. Prioritizing the run allows better technique and pacing when the body is freshest.
2. Scientific Research & Energy Systems
Research shows that exercise order matters for performance outcomes:
- Cardio Before Weights: Studies report a decrease in strength performance when aerobic exercise precedes resistance training, particularly for lower body strength.
- Weights Before Cardio: Resistance training first has less impact on subsequent aerobic performance and may even improve post-exercise fat oxidation.
- Run First for Endurance: A study by Hansen et al. (2005) showed that training order should match your priority—those who did endurance training first made greater aerobic progress.
- For Fat Loss: Total energy expenditure matters most for fat loss, not exercise order. However, some evidence suggests cardio after weights may enhance fat oxidation when glycogen is low.
Why?
- Strength training relies heavily on adenosine triphosphate-phosphocreatine (ATP-PC) and anaerobic glycolysis.
- Running depletes glycogen stores and induces central fatigue, impairing neuromuscular coordination.
3. Fatigue and Hormonal Effects
- Doing cardio before resistance training can increase cortisol levels, which may reduce anabolic hormone levels like testosterone and impair muscle recovery.
- Running after weights may enhance growth hormone (GH) and catecholamine response, particularly in high-intensity circuits (Schwanbeck et al., 2020).
4. Recovery and Injury Risk
- Running before strength may increase the risk of poor lifting form due to pre-fatigue, especially in compound movements like squats and deadlifts.
- Running after weights may be harder psychologically, but less risky biomechanically if done at a moderate pace.
Running After Strength Training: Pros & Cons
Pros
- Prioritizes Muscle and Strength Gains
- Enhances Fat Burn Post-Workout
- Improved Hormonal Environment
Cons
- Greater Fatigue Risk
- May Not Suit Endurance Priorities
Practical Recommendations by Goal
| Goal | Best Order | Why |
|---|---|---|
| Fat Loss | Weights → Cardio | Encourages fat burning after glycogen depletion |
| Muscle Gain | Weights → Cardio | Preserves strength and anabolic hormone response |
| Endurance Training | Cardio → Weights | Prioritizes running economy and technique under low fatigue |
| General Fitness | Either (Rotate) | Variety and personal preference may improve consistency |
| High-Intensity Workouts | Separate Days (if possible) | Avoids compounded fatigue, improves adaptation quality |
Split-Day Training Strategy
If optimal performance in both modalities is your goal (e.g., strength and cardio), consider splitting sessions:
- Morning: Strength training
- Evening: Cardio (or vice versa)
- Alternate training days: Mon (lift), Tue (run)
- Allow at least 6 hours between sessions to maximize adaptation (Wilson et al., 2012)
Final Verdict: Tailor It to Your Goal
There’s no universal best time to run—context matters.
- Want to get stronger and grow muscle? Lift first.
- Training for a race or building stamina? Run first.
- Trying to lose fat? Choose the timing that helps you burn more calories consistently.
Understanding how epinephrine, cortisol, glycogen usage, and neuromuscular fatigue play into training order gives you a powerful advantage in program design.
References
- Wilson, J. M., et al. (2012). Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises. Journal of Strength and Conditioning Research, 26(8), 2293–2307. https://doi.org/10.1519/JSC.0b013e31823a3e2d
- Hansen, D., et al. (2005). The effect of exercise training on physical fitness, coronary risk factors and psychological well-being in adults with obesity. Obesity Reviews, 6(1), 36–45.
- Schumann, M., et al. (2014). Cardio first or strength first? Impact of exercise sequence on health and performance outcomes. Sports Medicine, 44(2), 217–230.
- Cadore, E. L., et al. (2013). Concurrent training in elderly men: Effects on functional capacity and muscle strength. Journal of Strength and Conditioning Research.
- Kang, H., et al. (2009). Effects of sequencing resistance and aerobic exercise in women on acute hormonal responses and long-term training adaptations. European Journal of Applied Physiology.
- Schwanbeck, S., et al. (2020). Concurrent training and muscle hypertrophy: Does the interference effect exist? Journal of Functional Morphology and Kinesiology.
