Summary
Dr. Berg addresses the optimal timing for high-intensity exercise, concluding that evening workouts are superior to morning workouts. The primary reasoning centers on cortisol management and recovery efficiency, which maximizes the benefits of intense training.
Key Takeaways
- Evening is the best time for high-intensity exercise, supported by multiple studies
- Cortisol spikes from evening workouts clear out faster compared to morning workout cortisol spikes
- Better recovery is observed when training in the evening versus the morning
- Low-intensity activity like walking is acceptable in the morning, especially for those with adrenal issues
- Athletes training twice per day should schedule their intense session in the evening and walking/light activity in the morning
- Evening training may also produce better testosterone improvements
- Dr. Berg personally trains between 6–8 PM
Details
Why Evening Outperforms Morning for High-Intensity Work
Research cited by Dr. Berg indicates that evening training leads to significantly better recovery compared to morning training. While high-intensity exercise does spike cortisol regardless of timing, the key distinction is clearance rate — cortisol elevated by an evening workout dissipates more quickly than cortisol generated from a morning session. This faster clearance supports better overall recovery and allows the body to maximize training adaptations.
What Counts as “High-Intensity”
The evening timing recommendation specifically applies to:
- High-intensity interval training (HIIT)
- Heavy resistance or strength training
- Any demanding, high-effort workouts
Morning Exercise: When It’s Still Acceptable
Morning exercise is not entirely discouraged — it depends on intensity and individual profile:
- Walking and other low-intensity movement can be done in the morning without issue
- Individuals with adrenal fatigue or who are considered an “adrenal type” are specifically noted as appropriate candidates for morning low-intensity activity
- The concern is not morning movement in general, but morning high-intensity output
Two-A-Day Training Protocol
For competitive or advanced athletes training twice per day:
- Perform walking or light activity in the morning
- Reserve the intense workout for the evening
- This split is expected to yield better performance and recovery outcomes, including improved testosterone response