🏃♂️ Vegan Fuel for the Field: Study Shows Plant-Based Diets Support Athletic Performance—but With a Catch
As more athletes explore plant-based living, new research sheds light on how vegan diets hold up under the pressure of intense sports training and where they might fall short without careful planning.
A recent pilot study, “The VegInSoc Study”, published in Nutrients, followed semi-professional soccer players over eight weeks to examine how a vegan diet impacts their nutrition, body composition, and athletic performance. The findings? Promising for endurance and cardiovascular gains, but with cautionary notes on protein intake and lean muscle mass.
🌱 Plant-Powered Players: The Study at a Glance
Researchers in Potsdam, Germany, tracked two self-selected groups from the SV Babelsberg 03 soccer club: one vegan, one omnivorous. While small in scale, 15 athletes completed the study – the project offers key takeaways for sports professionals, fitness enthusiasts, and plant-based athletes alike.
All participants trained intensively, with daily sessions and frequent match days. Despite no formal dietary intervention beyond food tracking, athletes in the vegan group naturally consumed more fruits, vegetables, grains, legumes, nuts, and plant-based dairy alternatives.
🔍 Key Nutritional Insights
Both groups fell short of recommended energy and carbohydrate intakes for their high training demands. However, the vegan players consistently ate more carbohydrates a crucial fuel for endurance sports
Notably, protein intake lagged in the vegan group, a finding that raises red flags about potential muscle mass loss, especially during periods of intense training or caloric deficit. While micronutrient intake, including vitamins A, E, K, and B12, was higher in vegans (thanks to supplements), ensuring adequate levels of iron, iodine, calcium, and vitamin D remains essential.
No major nutrient deficiencies emerged in blood tests during the eight weeks, suggesting that short-term vegan diets can be nutritionally sufficient with proper support.
🏋️ Muscle Mass & Cholesterol: The Double-Edged Sword
The study revealed a 2 kg decrease in lean body mass among vegan participants —highlighting a critical concern for athletes relying on plant-based diets without protein optimization.
However, the benefits were clear elsewhere: vegans saw a notable drop in LDL (“bad”) cholesterol, and resting heart rates improved across both groups, suggesting positive cardiovascular adaptations.
🏃♀️ Performance Metrics: Vegans Hold Their Own
Performance-wise, vegan athletes matched or exceeded their omnivorous peers in several markers:
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Maximum running speed increased slightly more in the vegan group.
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VO₂max improvements (a key marker of endurance fitness) were more pronounced in vegans, but this was mostly linked to body weight reduction rather than increased aerobic capacity.
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Time to exhaustion rose in both groups, showing similar gains from consistent training.
Higher lactate levels in vegan participants hinted at elevated anaerobic metabolism, likely fueled by their higher carbohydrate intake, a potential edge in high-intensity scenarios.
🧠 What This Means for Vegan Athletes
While the short duration and small sample size limit sweeping conclusions, the VegInSoc study supports what many in the plant-based performance community already believe: vegan diets can sustain and even enhance athletic performance—if managed wisely.
For athletes eyeing long-term performance gains on a vegan diet, strategic planning is non-negotiable. Prioritizing complete proteins (via combinations like legumes and grains), supplementing critical nutrients, and monitoring body composition closely can help avoid potential pitfalls like muscle loss.
📣 The Bottom Line
“A short-term vegan diet may be suitable for semi-professional soccer players,” the study concludes. But success hinges on education, supplementation, and smart nutrition strategies—especially when muscle retention and recovery are on the line.
As more athletes turn to plant-based performance, studies like VegInSoc help break stereotypes and illuminate both the benefits and the challenges of fueling with plants. The future of sports nutrition might just be greener than we think.
Source: https://bit.ly/3TQazHr
Nebi, J., Bruns, P., Meier, M., et al. (2025). The Effect of an 8-Week Vegan Diet on the Nutritional Status and Performance of Semi-Professional Soccer Players—Results of the VegInSoc Study. Nutrients. https://doi.org/10.3390/nu17142351
