This study aims to investigate the impact of two plant-based diets-whole food plant-based (WFPB) and plant-based meat alternatives (PBMA)-vs. an omnivorous diet (Animal) on endurance and muscular strength in recreational athletes.

Plant-based diets are environmentally sustainable and beneficial for cardiovascular health, but athletes are often concerned that these diets do not contain enough protein to support athletic performance. However, few randomized trials investigating the effect of plant-based vs. omnivorous diets on athletic performance have been conducted. Within this randomized crossover trial, recreational runners and resistance trainers will be assigned to three diets for four weeks each (WFPB, PBMA, and Animal). PMBA is an emerging, modern type of plant-based diet for which the impact on athletic performance has not yet been assessed. Participants will complete athletic fields at baseline and after each diet, and athletic performance on diets and study feasibility in this cohort of recreational athletes will be assessed. The study design was inspired by the original SWAP-MEAT study that investigated cardiovascular risk factors in adults consuming 8-week omnivorous and plant-based meat alternative diets (Crimarco, 2020).

Inclusion Criteria:

• Generally healthy omnivorous adults between 18 and 35 years of age who report typically consuming at least 1 serving of meat per day and are willing to consume ~2 servings per day of animal meat, plant-based meat alternatives, and whole-food plant proteins.
• Participants will have been consistent recreational runners or weightlifters (3-4 times per week) for at least the prior 1 year, and currently run or lift 3-4 times per week.
• Runners will engage in at least 150 minutes of moderate-to-vigorous aerobic activity or 75 minutes of vigorous activity per week. All participants will have habitually consumed an omnivorous diet for at least months.
• Participants will have self-reported good health and BMI 18.5-30.0.
• Participants must be able to commit to running or resistance training at least 3-4 times per week for the 12 week duration of the study.

Exclusion Criteria:

• Individuals who have participated in any restrictive diet within the last month, have any known nutrient intolerances, have orthopedic limitations, are participating in any other physical activity or diet study;
• Individuals consuming any performance enhancing drugs or medications known to interfere with athletic performance;
• Individuals who have a chronic disease or eating disorder, are currently pregnant or intend to become pregnant in the next three months, or have an intent to compete in any physical activity competition within the next 3 months.