Vegan strength, plant proteins, and recovery: what the evidence actually says (2 studies analysis)

Plant-based eating is everywhere in sport right now, from recreational lifters to endurance athletes to people simply trying to feel better between sessions. The promise is tempting: better health, less inflammation, faster exercise recovery, maybe even improved athletic performance.

But when you strip away the hype, most athletes want answers to two practical questions:

1. 1.If I switch to a vegan diet, will my strength training suffer?
2. 2.If I use plant-based protein, will I recover as well as I would with whey?

Two recent papers help frame what we know, and what we still do not know, about training science in this space.

Change to a Plant-Based Diet Has No Effect on Strength Performance in Trained Persons in the First 8 Weeks—A 16-Week Controlled Pilot Study (Isenmann et al., 2023)

This study asked whether switching from an omnivorous diet to a vegan diet changes strength performance in trained lifters over the first 8 weeks of the switch.

Methods

Fifteen omnivorous, strength-trained adults were recruited, and 10 completed the full 16 weeks. Participants kept their usual strength training routines and documented all food intake daily. Strength was tested every four weeks using one-repetition maximum (1RM) protocols for leg press and bench press. The study ran as an 8-week omnivorous phase followed by an 8-week vegan phase, with no supplements added specifically to “fix” the transition.

Key results

• Bench press and leg press strength (absolute and relative) did not meaningfully change after switching to a vegan diet during the first 8 weeks of the vegan phase.
• Total calorie intake stayed broadly similar across phases, with only a small difference between diet phases.
• Carbohydrate intake showed a small to moderate increase during the vegan phase.
• Protein intake dropped during the vegan phase, including relative protein intake, which fell to around ~1.1 g/kg/day, below common athlete-focused recommendations cited by the authors (1.2 to 2.0 g/kg/day).
• Body weight and BMI showed statistically significant but trivial treatment effects, with no meaningful time trend.

Authors’ conclusions: In this small pilot, switching to a vegan diet did not improve or harm strength performance over the first 8 weeks, as long as calorie intake and carbohydrate intake were maintained. The main nutrition risk signal was a drop in protein intake, which could matter more for hypertrophy and long-term adaptation than for short-term strength maintenance.

Effect of Plant-Based Proteins on Recovery from Resistance Exercise-Induced Muscle Damage in Healthy Young Adults—A Systematic Review (Govindasamy et al., 2025)

This paper asked whether plant-based protein supplementation supports recovery from resistance exercise-induced muscle damage, and how it compares with animal-based proteins.

Methods

The authors systematically searched eight databases through 1 May 2025 and included 24 studies (mostly randomized controlled trials). They reviewed plant proteins such as soy, pea, rice, hemp, potato, and plant protein blends, with typical doses from 15 to 50 g, often taken post-exercise. Outcomes included muscle protein synthesis (MPS), delayed-onset muscle soreness (DOMS), inflammatory biomarkers (like creatine kinase), muscle function, and fatigue. Because studies varied widely in protocols and measurements, the authors did not run a meta-analysis and instead used narrative synthesis and risk-of-bias assessments.

Key results

• Single-source plant proteins often showed limited advantages compared with whey in acute recovery settings, especially when essential amino acid availability and leucine content were lower.
• Well-formulated plant protein blends can stimulate MPS similarly to whey when dosed high enough, with the review highlighting a practical threshold of roughly ≥30 g protein with ~2.5 g leucine.
• Some individual studies reported improvements in subjective recovery measures or reduced muscle-damage biomarkers with soy or pea protein, but results were inconsistent.
• The overall evidence base was limited by small samples, heterogeneity in protocols, and moderate to high risk of bias in a meaningful fraction of studies.

Authors’ conclusions: Plant-based proteins can support exercise recovery, and blends (plus adequate dosing and leucine) appear most capable of matching whey for post-exercise MPS. However, the evidence is not definitive, and better long-term trials, especially in vegan athletes, are still needed.

Synthesis: where these studies agree, and where they differ

These papers approach the plant-based question from two angles. The pilot study tests a real-world dietary switch (omnivore to vegan) and measures strength outcomes. The systematic review focuses on plant-based protein supplementation and recovery biology, especially MPS and soreness after damaging resistance exercise.

Where they agree:

• Plant-based approaches do not automatically harm training outcomes in the short term.
• Protein quality and total protein intake are the main potential weak links when athletes go plant-based.
• Calories still matter. When energy intake is steady, performance tends to be more stable.

Where they differ:

• The pilot study shows strength can be maintained even when protein intake drops, at least over 8 weeks, but it did not measure muscle growth, fat-free mass changes, or deeper recovery markers.
• The systematic review suggests some plant proteins are less competitive than whey for acute recovery signals unless they are blended and dosed appropriately, but this literature is noisy and methodologically mixed.

Evidence-based conclusions (5)

1. 1.A short-term switch to a vegan diet does not appear to change maximal strength performance if training stays consistent and calorie intake (and likely carbohydrate intake) is maintained.
2. 2.Protein intake commonly drops during an unstructured transition to vegan eating, which is a risk factor for hypertrophy and longer-term adaptation even if short-term strength looks fine.
3. 3.Plant proteins can support recovery, but single-source options often underperform whey in acute settings unless dosing and amino acid profile are optimized.
4. 4.Plant protein blends, taken in sufficient doses and with enough leucine, can produce post-exercise MPS responses comparable to whey in some studies.
5. 5.The current evidence is promising but not “settled,” because many studies are small, use different exercise damage models, and carry meaningful risk of bias.

What this means for your training

Here is how I would apply this evidence as a coach, keeping it practical and honest.

• If you switch to vegan, protect your calories first. The strength study suggests performance stayed stable when total energy intake did not meaningfully drop. If you unintentionally under-eat during the transition, your athletic performance and exercise recovery are more likely to suffer than if your protein source changes.
• Treat protein as a target, not a vibe. In the pilot study, relative protein intake fell below typical athlete recommendations during the vegan phase. Build your day around “anchor” protein servings (tofu, tempeh, seitan, soy yogurt, lentils plus grains, or a plant protein shake), rather than hoping it adds up.
• Use plant protein blends post-workout when recovery matters most. The systematic review’s most consistent “win condition” for plant proteins was blends with adequate dosing and leucine. Practically, that means a higher-protein post-lift feeding, often a shake, that is designed to hit a meaningful amino acid dose, not just 15 g of something random.
• If you insist on single-source powders, dose up. The review suggests that one reason whey tends to win is amino acid availability (especially leucine). If you are using a single-source plant protein, a larger serving may be necessary to achieve a similar recovery stimulus.
• Watch your training feedback loop for 3 to 6 weeks. Strength can look stable in the short term even if recovery quality changes subtly. Track a few markers: session-to-session performance, soreness that lasts beyond 48 to 72 hours, sleep quality, and appetite. If these drift in the wrong direction after going plant-based, the first fixes are usually energy intake, protein dose per meal, and post-training nutrition.
• Do not confuse “no change in 1RM” with “no change in adaptation.” The pilot study is reassuring for strength maintenance over 8 weeks, but it cannot tell you what happens to hypertrophy, body composition, or long-term strength progression if protein stays low. If hypertrophy is your goal, you should be more conservative and more structured with protein.