Plant Performance

Athletes all over the world are going plant-based, and for good reason. You can hit peak performance with plants. GP and athlete Dr Malcolm Mackay unpacks the benefits of this game-changing lifestyle to support your training, competition and recovery. Article first published in Nourish Magazine.

More and more leading athletes are adopting a whole food, plant-based (WFPB) diet for improved sports performance. The release of the The Game Changers documentary has been a tipping point for interest in WFPB nutrition – a performance-enhancing strategy that is safe, ethical and available to everyone, from leading sportspeople to regular gym users.

As an athlete myself, I have a long-standing interest in sports nutrition. Distance running and a love of snow skiing motivated me to begin my plant-based nutrition journey when I was in medical school, learning about the damage the Western diet was causing to our arteries and other aspects of health. It seemed to work for me, I ran a 2:32 marathon in 1980 and had a couple of first places in my early triathlons. Even now at age 60, I can still run a reasonable half marathon – something I don’t think I would be fit enough to do had I spent decades eating chicken, cheese and oil.

The benefits of WFPB nutrition combined with avoidance of animal products and processed foods, impact the whole cycle of sports performance – training, competition, and recovery. Carbohydrate-rich whole plant foods not only provide optimal fuel while supporting blood flow to muscles during training and competition but also support the critically important recovery phase. These foods counteract the oxidative stress and inflammation caused by intense exercise, resulting in fewer overuse injuries and a shorter recovery time, giving athletes the capacity to do quality training sessions, more often.

Whole plant foods counteract the oxidative stress and inflammation caused by intense exercise, resulting in fewer overuse injuries and a shorter recovery time

But what about protein?

The focus on protein, and particularly animal protein, is the most persistent myth in sports nutrition. No one who consumes adequate calories from a variety of whole plant foods is likely to suffer reduced performance due to lack of protein.

While the term ‘protein’ is used in common language and some diet guides to describe certain foods, this is misleading. It implies that these foods are composed of protein only and that other foods do not provide any. Dietary guidelines can also add to the confusion by describing a protein group that includes legumes and nuts but not wholegrains, when on a per-calorie basis, wholegrains have the same protein content as nuts. All whole plant foods are a complex ‘package deal’ with varying amounts of protein. Only processed foods like olive oil, coconut oil and sugar contain zero protein. The natural plant protein package also includes an abundance of health-supporting phytonutrients and dietary fibre, which are absent from the animal protein ‘package’. In fact, animal proteins often include health-damaging and inflammatory substances. High protein diets based on animal products are deleterious to health and athletic performance.

While some of the effects are due to the other toxic components of the animal protein ‘package’, the quantity and composition of the protein itself has the following adverse effects on health and athletic performance.

  • Acid load (reducing tolerance to lactic acid build-up during intense exercise).

  • Negative calcium balance and bone loss due to acid load.

  • Kidney stress and long-term damage.

  • Dehydration and electrolyte depletion.

  • Insulin resistance (causing reduced muscle glycogen).

  • Adverse shift in gut microbiome profile.

  • Adverse impact on cardiovascular function.

The primary nutrition issue for plant-based athletes is consuming enough calories to support their heavy training loads. Failure to thrive on a plant-based diet is usually the result of not eating enough calories. The carbohydrate-rich foods that provide the ideal fuel for athletes – such as oats, brown rice, wholemeal pasta, potatoes and beans – have only half the calorie density of meat, chicken and fish. This means twice the quantity will be required to get the same number of calories. Eliminating vegetable oils (the most calorie dense and nutrient poor food group) further dilutes the calorie density of meals, so athletes need to adapt to eating larger meals and more snacks.

The natural plant protein package includes an abundance of health-supporting phytonutrients and dietary fibre.

Plant power!

Plant-based athlete (climber)
Plants contain all the essential amino acids.

Plants contain all the essential amino acids and have an amino acid profile that is more health supporting than that of animal proteins. Athletes do not need to choose higher-protein foods to meet their extra protein needs because they consume more calories than the general population, which means more food and more protein. A typical WFPB diet provides about 12 percent protein, which equates to approximately 1.5 grams of protein per kilogram of bodyweight for a moderately active person, as opposed to an elite athlete. If athletes are (unnecessarily) anxious about getting enough protein on a WFPB diet, this can be increased by consuming more of the higher-protein plants – more legumes, higher-protein grains (e.g. wheat rather than rice), higher-protein tubers (potatoes rather than sweet potatoes) and more protein-rich, low calorie, non-starchy vegetables.

Popular sports nutrition emphasises the importance of consuming protein as soon as possible after exercise but much of the evidence supporting this idea is highly reductionist and may not translate to improvements in performance. It’s true that adequate food intake during the recovery period is important, including the protein that is naturally present in the wholefood, plant-based package. However, after a big workout, it may be better to focus on hydration and phytonutrient-rich plant foods that neutralise inflammation and protect damaged tissues.

Protein supplements are unnecessary and can displace calories that might otherwise have come from nutrient-rich whole plant foods. Inadequate protein intake is only likely to occur in the context of inadequate calorie intake (or on diets built on sugar and oil). Most of us easily meet our protein needs and any additional protein is deaminated in the liver (increasing blood urea levels) and then metabolised to sugar and fat, which is used for energy or stored in the body. Adding protein powder to your meal is like adding sugar – calories without any of the fibre, nutrients and phytonutrients.

It’s simple – eat peas, not pea protein.

Nutrients, when removed from their whole food context and concentrated, can also have unanticipated adverse effects. For example, taking more of one mineral can impair the absorption of other minerals. Animal studies performed in the past suggest that increased intakes of plant protein do not promote cancer and ageing in the same way that animal protein does. Whole plant foods contain the right balance of all the nutrients and phytonutrients that we need for optimal health – we don’t need to try and outsmart nature. The exceptions here are vitamin B12 and vitamin D, which we would get from bacteria and sunshine if we lived in nature, but we don’t these days and supplements may be recommended. Iron supplements can also be appropriate for short-term correction of proven deficiencies.

The proof of plant performance

A WFPB diet can improve sports performance in the following ways.

  • The high carbohydrate content maximises glycogen stores, which provides fuel for endurance events and long training sessions.

  • The lower fat content and higher water and fibre content of whole plant foods means they have a lower energy density, making it easier to maintain a lean physique.

  • It supports optimal cardiovascular health. Arteries remain free of plaque and the improved endothelial (artery lining) health allows arteries to dilate fully, improving blood flow to the heart and muscles.

  • The nitrates in leafy green vegetables and beets boost nitric oxide production, improving blood flow to muscles and reducing blood pressure.

  • Blood viscosity and red blood cell stiffness is reduced, boosting capillary blood flow, and delivering more oxygen to where it’s needed.

  • The antioxidant phytonutrients in whole plant foods neutralise the free radicals that are produced as byproducts of our cellular energy metabolism and protect our cells against exercise-induced damage.

  • Many phytonutrients in whole plant foods have powerful anti-inflammatory actions. These dampen down sports related tissue inflammation without the harmful side effects of anti-inflammatory pharmaceuticals.

  • Immune function is improved through the action of whole plant food phytonutrients and the absence of inhibitory effects from animal products and processed food.

  • WFPB nutrition supports improved mood and energy levels, essential for consistent and goal directed training.

Plant-based athletes can easily meet and exceed their protein requirements by eating adequate calories of whole plant foods, which provide protein in a form that our bodies are designed to process. The WFPB diet also comes with a host of benefits that support holistic health and wellbeing. It’s simple – eat peas, not pea protein.


This article is republished with permission from

Dr Shireen Kassam - founder of Plant Based Health Professionals UK, and Doctors for Nutrition International Advisor

More about the author

Dr Malcolm Mackay is Doctors For Nutrition's General Practitioner Resources Advisor.

Read his full bio here.

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