Coach's Corner: How Sleep And Stress Impact Performance, And Why It Matters for Athletes
Oct 24, 2025 / Author: Clif Marshall
Clif Marshallis D1 Training's Senior Director of Coaching and Pro Training. Each week in D1 Daily, Clif shares his insight gained from more than 20 years working in strength and conditioning.
In elite sports, athletes train their bodies to perform at the highest level.
But what happens between workouts often determines success more than what happens during them.
Two of the biggest performance factors off the field are sleep and stress management.
1. Why Sleep Matters
Sleep is when the body repairs, rebuilds, and resets. Without it, training results stall — no matter how hard the athlete works.
Muscle Recovery: During deep sleep, the body releases growth hormone, which repairs muscle tissue and builds strength.
Nervous System Reset: Sleep restores coordination, reaction time, and decision-making — all key for game-day performance.
Injury Prevention: Sleep-deprived athletes have higher rates of soft tissue injuries and slower healing times.
Hormonal Balance: Lack of sleep raises cortisol (the stress hormone) and lowers testosterone, limiting muscle growth and recovery.
Target for Athletes
8–10 hours per night (plus naps during high-volume training phases).
Maintain a consistent sleep schedule — same bedtime and wake-up time, even on weekends.
Coach Clif's Tip
Treat sleep like a workout — schedule it, track it, and protect it.
Athletes experience both physical stress from training and mental stress from life, competition, and expectations. When stress isn’t managed, it becomes chronic, and performance drops.
Effects of Chronic Stress
Slower recovery and fatigue
Reduced focus and confidence
Suppressed immune function
Elevated injury risk due to muscle tightness and poor movement patterns
How to Manage It
Breathing routines: 5–10 minutes of slow nasal breathing post-workout or before bed lowers cortisol.
Active recovery: Walking, stretching, or yoga helps calm the nervous system.
Faith / Gratitude practices: Help athletes shift mindset from pressure to perspective.
Nutrition and hydration: Keep the body balanced and energy stable.
Better sleep → lower stress → faster recovery and focus.
When athletes fix one, they usually fix the other.
4. The Performance Payoff
When sleep and stress are dialed in:
Reaction time improves
Decision-making sharpens
Hormones optimize for strength and endurance
Confidence and focus rise under pressure
LeBron James at 40 years old is one of the best athletes on the planet, with multiple NBA titles and MVP awards. What's the key to the veteran's success? “At least eight hours of sleep, every night.” he says.
Clif Notes Takeaway
“You don’t grow during training — you grow when you recover.”
For serious athletes, sleep and stress control aren’t optional. They are the foundation for speed, strength, and long-term performance.
