Fuelling Performance with Plant-Based Nutrition

by Aoife Quinn

Plant-based diets are becoming increasingly popular among athletes, but questions are often asked around protein, strength and performance. Can you really meet your needs without animal products? The short answer…Yes! The evidence shows you can, provided your diet is well planned.

Can Vegetarian Diets Support Athletic Performance?

Research shows that vegetarian and vegan diets can support similar strength, endurance and recovery outcomes as omnivorous diets  (i.e. those containing both plant & animal based foods). Performance is driven by overall energy and nutrient intake, rather than the inclusion of animal foods specifically.

For athletes, the real key is to ensure adequate intake, especially for protein and total calories.

Protein and Muscle Building: What Matters Most?

Protein plays a central role in muscle repair and growth. Both exercise and protein intake stimulate muscle protein synthesis (MPS), which is super important for recovery and adaptation.

General sports nutrition guidelines suggest:

• Around 1.2–2.0 g protein per kg body weight per day
• Distributing protein evenly across the day
• Including ~20 g (or more) protein per meal, every 3–4 hours

Recent evidence suggests that plant proteins can support muscle building just as effectively as animal proteins, when total protein intake is sufficient (that’s the key bit!)

What About Protein Quality?

A common concern is that plant proteins are “lower quality.” This belief is due to the fact that plant based protein sources have:

• Lower levels of certain essential amino acids
• Slightly lower digestibility

However, in practice, this is not a major issue if athletes:

• Eat a variety of plant protein sources (the more the merrier!)
• Consume enough total protein (well disturbed across the day)
• Include sources rich in leucine, a key amino acid for muscle building (view it as the ‘on’ switch for muscle protein synthesis)

Plant-based leucine sources include soy foods, lentils, beans, nuts, seeds and unsweetened cocoa powder. Other vegetarian sources include eggs & dairy products. 

Emerging research shows that when we consume enough protein overall, plant proteins can be just as effective at stimulating muscle protein synthesis.

Carbohydrates: A Natural Strength of Plant-Based Diets

Plant-based diets are typically rich in carbohydrates, the primary fuel for exercise (think ‘fuel for the car’). Wholegrains, fruits, starchy vegetables and legumes help to support:

• Training performance
• Glycogen (energy stored in your muscles & liver) replenishment
• Overall recovery

This can be a natural advantage, particularly for endurance athletes.

Other Key Nutrients for Vegetarian Athletes

While protein often gets the most attention, other nutrients are equally important:

• Iron: Needed for oxygen transport. Found in lentils, beans and leafy greens. Pair with vitamin C to enhance absorption.
• Vitamin B12: Not naturally present in plant foods – those following a completely plant-based diet (i.e. vegan diet) need to include fortified foods or supplements.
• Calcium: Important for bone health. Found in dairy or fortified plant alternatives and tofu. (Check the ingredients label of your plant based milk to ensure they have added calcium)
• Omega-3 fats: For brain health! Include flaxseeds, chia seeds and walnuts (a supplement may be needed).
• Energy/calorie intake: High-fibre diets (which plant-based often are) can be very filling, so athletes need to be mindful of if they are eating enough calories to meet training demands.

Practical Tips for Vegetarian Athletes

• Aim for regular protein intake across meals and snacks
• Include a variety of plant proteins (beans, lentils, tofu, dairy, eggs if included)
• Consider slightly higher protein intakes to account for differences in digestibility
• Use fortified foods or supplements where needed (e.g. B12)
• Plan meals to meet energy needs, especially during intense training – Include convenient, energy-dense options like smoothies, crackers with nut butter or yoghurts with seeds & nuts to meet overall calorie demands

To conclude…

A vegetarian or plant-based diet can fully support athletic performance, strength and recovery. The key is not whether protein comes from plants or animals, but whether you’re having enough overall, the types you have are varied and also well distributed throughout the day.

With the right approach, vegetarian and plant-based eating can be a practical and effective way to fuel performance. For more personalised support and guidance, book in with one of our dietitians/with Aoife, our sports dietitian.