The Study
Energy balance in cyclists on plant‐based diets during a 30‐day, 4300‐km ride across Canada: Two case studies
This study watched two people ride their bikes across Canada and measured what they ate and how their bodies changed. It doesn't tell us if plant-based diets are better or worse for athletes — it just shows what happened to these two people.
Analysis score
Maximum 30 for a case report.
Where the score came from
Two people rode their bikes across Canada for 30 days, eating only plants, and didn't lose much muscle or weight—even though they burned tons of calories.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 530 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this shows that even extreme endurance efforts can be supported by plant-based diets if protein and calories are high enough.
- 2One cyclist lost 2.3 kg of fat and gained 1.4 kg of muscle; both ate over 2.3 grams of protein per kg of body weight daily and increased food intake by 421–761 kcal/day.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Physiological Reports
Year
2025
Authors
Sarah A. Purcell, Edward L. Melanson, S. Creasy, Matthew D Barros, Stephanie Ramage, Sarah A. Craven, Carla M. Prado
Related Content
Claims (6)
People burn a similar amount of energy each day, even when they exercise more or less than usual.
In two athletes undergoing a 30-day ultra-endurance ride, resting energy expenditure did not increase as expected despite high physical activity and changes in body composition.
Two plant-based athletes increased their daily calorie intake by 421 to 761 kilocalories during a 30-day ultra-endurance ride. One athlete maintained energy balance, while the other had a slight energy deficit.
Two recreational cyclists following a plant-based diet maintained their overall body weight and muscle mass during a 30-day, 4300-km cycling trip across Canada, despite high energy expenditure; one cyclist lost 2.3 kilograms of fat and gained 1.4 kilograms of muscle while consuming more than 2.3 grams of protein per kilogram of body weight daily.
Athletes on plant-based diets sustained high levels of physical activity during a 30-day ultra-endurance cycling event without losing significant body mass, matching the energy expenditure levels of professional cyclists in multi-week races.
Athletes following a plant-based diet and consuming more than 2.3 grams of protein per kilogram of body weight per day during a 30-day ultra-endurance ride met their protein needs using only plant foods, without any supplements.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.