nutrition7 min readFR

Supplements: What Coaches Really Need to Know

Protein, creatine, BCAAs, vitamin D: separate what genuinely works from marketing noise in the world of supplements.

Équipe I Train With You·

What the Data Actually Says

The supplement industry is worth billions, but the majority of products have little or no solid scientific evidence behind them. As a coach, your role is to guide your clients through this maze.

Level A Evidence (Strongly Recommended)

Creatine Monohydrate

The most extensively studied supplement. It increases performance on short, intense efforts (7-12%) and supports muscle mass gain. Dose: 3-5 g per day.

Protein Powders (whey, casein, plant-based)

They supplement daily protein intake when diet alone is insufficient. No magic: they don't replace a balanced meal.

Caffeine

Improves aerobic performance, strength, and focus. Effective dose: 3-6 mg/kg, 60 minutes before exercise.

Level B Evidence (Useful in Some Cases)

  • Beta-alanine: reduces muscle fatigue for 1 to 4-minute efforts
  • Magnesium: useful if deficient (common in active athletes)
  • Vitamin D3: important if sun exposure is insufficient

To Avoid or Treat with Scepticism

  • BCAAs: unnecessary if total protein intake is sufficient
  • Fat burners: barely effective, sometimes dangerous
  • Mass gainers: often too high in sugars

How to Talk About This with Your Clients

Always recommend brands that are transparent about their formulations. Make clear that supplements don't compensate for a poor diet. And log your clients' supplements in I Train With You for comprehensive nutritional tracking.

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