Is carbohydrate loading just placebo? 🧐
Common practice, but rightfully questioned.
Beyond Belief? Absence of Double-Blinding and Limited Ecological Validity in Carbohydrate Loading Research
Study Details
This new review examined findings from 14 carb loading studies to establish if it actually improves performance, outwith the placebo effect 🔍
Here are the key findings ⬇️
Key Findings
📚 Of 14 eligible carb loading studies, only 2 used double-blind, placebo-controlled designs
🥤 Only 4 of the 14 studies provided carbohydrate during the exercise test, limiting real-world relevance
⚠️ The 2 double-blind studies that did include appropriate in-exercise carbohydrate found no performance benefit from carb loading
🔍 Many older studies tested carb loading without pre- or during-exercise carbohydrate, which does not reflect current endurance fuelling practice
🧠 The positive effects seen in some unblinded studies may partly reflect belief, expectation, or placebo effects rather than carbohydrate loading alone
💭 The effect sizes from the unblinded studies with in-exercise carbohydrate were similar to reported placebo effects for nutritional interventions
The authors did not argue that glycogen is unimportant, they argued that the evidence for extra benefit from above-normal carbohydrate loading needs stronger testing ✅
Conclusion
Overall, current evidence is inconclusive on whether 24–48 h carbohydrate loading adds performance benefit when placebo effects are controlled and in-race fuelling is optimised 🔍
Even if effects are down to placebo, this shouldn’t be discounted in applied settings.
If there is a mechanism there to support employment of carb loading (“glycogen stores”), then placebo isn’t bad if it improves performance ⚙️
Or maybe I just like eating lots of pasta 🫣
Reference
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