Marathon runners need 200-1000mg of vitamin C daily to counteract the extreme oxidative stress that depletes reserves faster than food can replace them. Marathon training creates a perfect storm for vitamin C depletion — hours of sustained oxidative damage, elevated cortisol, and compromised nutrient absorption all working against your immune system. According to the Journal of Sports Medicine, endurance athletes have 2-6 times higher vitamin C turnover rates than sedentary individuals, yet most reach for basic ascorbic acid tablets that cause stomach upset and poor absorption. The reality is your training demands a more sophisticated approach than grabbing oranges from the kitchen.
S&J Ultimate C
Triple-form vitamin C · Zero calories · Zero sugar · Family-safe
Why Marathon Training Destroys Your Vitamin C Reserves
Every mile you run generates massive oxidative stress that rapidly burns through vitamin C stores. Marathon training produces reactive oxygen species faster than your body can neutralize them, forcing vitamin C to act as your primary antioxidant defense system. This creates a cascade effect — depleted vitamin C means compromised collagen synthesis, slower muscle repair, and weakened immune barriers right when you need them most. According to the International Journal of Sport Nutrition, marathon runners show 40% lower plasma vitamin C levels during peak training compared to base periods. The problem compounds because high-intensity training also reduces nutrient absorption in your gut, meaning even adequate dietary vitamin C may not reach your bloodstream effectively. Your body is essentially fighting a losing battle — burning through vitamin C reserves faster than traditional supplementation can replenish them.
What Actually Works for Marathon Training Recovery
1. Time your vitamin C intake around training — take half your dose 30 minutes pre-run and half within 2 hours post-run when oxidative stress peaks. 2. Focus on buffered forms that won't cause stomach upset during long training sessions or early morning runs. 3. Combine with zinc to support the 300+ immune enzymes that marathon training compromises. 4. Choose triple-form vitamin C like S&J Ultimate C that provides three absorption pathways — pharmaceutical-grade ascorbic acid for potency, sodium ascorbate for quick uptake without stomach irritation, and calcium ascorbate for sustained release. 5. Add bioflavonoid enhancers — Ultimate C includes citrus bioflavonoids that multiply vitamin C absorption and rosehip extract for additional natural vitamin C plus skin-supporting antioxidants. One scoop in water tastes like orange juice, contains zero calories and zero sugar to fit any nutrition plan, and delivers clinically meaningful amounts your body actually uses instead of eliminating unused.
Marathon Training Vitamin C FAQ
How much vitamin C for marathon training?
Marathon runners need 200-1000mg daily depending on training volume and individual needs. Start with 200-400mg daily during base training, increasing to 500-1000mg during peak weeks when oxidative stress is highest.
Do marathon runners get sick more often?
Yes, marathon runners have 2-6 times higher upper respiratory infection rates, especially in the 1-2 weeks following intense training or racing. This happens because prolonged exercise temporarily suppresses immune function while depleting protective nutrients like vitamin C.
What supplements do marathon runners need?
Essential supplements include vitamin C for antioxidant protection, zinc for immune enzyme function, and electrolytes for hydration. Focus on forms that won't cause stomach upset during training and provide sustained release rather than quick spikes.
Upgrade Your Immunity
Your marathon training demands more than basic vitamin C tablets that upset your stomach and get eliminated unused. Ultimate C delivers triple-form vitamin C through three absorption pathways, enhanced by citrus bioflavonoids and rosehip extract, plus zinc for immune enzyme support — all in a zero-sugar, zero-calorie formula that tastes like orange juice.
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