Is going vegan really game-changing for cyclists?

In the opening sequence of The Game Changers documentary, presenter James Wilks – a former mixed martial arts champion – explains that his interest in veganism started when he got injured and began genning up on recovery.

He claims to have spent 1,000 hours researching recovery-boosting nutrition. One thousand hours? Assuming he studied 9am to 5pm without lunch breaks, that’s a full four months of solid reading. Anyway, amid these mountains of paperwork, he stumbled upon an article purporting to prove that Roman gladiators (“the original professional fighters”) ate a mostly plant-based diet.

Wilks’s mind is blown. Over the rest of the film, he advances the case, in no uncertain terms, that eating only plant-based foods is better for recovery, health and – crucially – sporting performance. It was no surprise, then, The Game Changers garnered enormous attention, even among ordinarily hard-headed cyclists.

Full disclosure to kick off: I eat a mostly plant-based diet; I’m not a strict vegan, but I avoid meat and dairy products most of the time (largely for ethical reasons). If my position were prone to bias, it would be skewed in favour of The Game Changers – its message that veganism boosts sporting performance is good news for me. My job here, though, is to be unswervingly objective in answering this question: will going vegan make you a fitter, faster cyclist?

Quite early in the film, we meet Dotsie Bausch, the seven-time US national champion and Olympic silver medallist. This is the segment for the cyclists. Bausch tells us that she was in her mid-30s and “ready to retire” when she switched to a vegan diet, from which point she unexpectedly “just kept getting better” – pointing out that she went from struggling to leg-sled 300lb to pushing 585lb in sets of 60 reps.

She relives the pinnacle of her career: silver in the team pursuit at the London Games, where she stood on the podium aged 39.5 years – “I’m still the oldest person in my event to even go to the Olympic Games.”

The film implies the American’s late-career improvements were the result of her switch to a vegan diet. However, it doesn’t take much research to discover Bausch took up cycling relatively late, aged 26, as part of her recovery from an eating disorder. In light of which, the fact she was still improving at 35 was perhaps not so much proof of ‘plant power’ as the natural development of a huge talent that for many years had lain dormant and/or been hampered by improper fuelling. Of course, this is to take nothing away from her remarkable achievements.

I contacted Bausch by email and asked what made her so confident her improvements were the result of diet over and above other factors.

“Truly, this was the one thing that I changed,” she replied. “My coach and my training stayed consistent – it was the diet change that gave me this advantage. And, let’s be honest, I wasn’t getting any younger... when my body should have been resisting and slowing me down, I was actually getting fitter, stronger and more resilient.”

Bausch is a passionate advocate of veganism, and as a “plant-powered athlete” has become a professional influencer on the topic (dotsiebauschusa.com). Her anecdotal evidence is compelling – but is it supported by hard science?

A note of caution

Asker Jeukendrup is a sports nutritionist who works with WorldTour cyclists. He is unconvinced by the case for veganism constructed by The Game Changers. “Watching the film as a scientist, it becomes really clear after a few minutes it is going to be very one-sided,” he told me. “I looked at all the claims, and then looked for the actual evidence.” According to Jeukendrup, trustworthy research on how a vegan diet affects sporting performance is very thin on the ground. “There are some reviews, but they rely on a paucity of studies,” he explained. “Without research addressing the subject directly, the next best approach is to extrapolate from studies on related topics – such as the body’s synthesis of animal versus plant protein.” In which regard: “We do have solid science showing the opposite [to the film’s claim] – that a vegan diet is actually inferior. We know that, gram for gram, animal protein outperforms plant protein.” 

In the film, Wilks boldly claims that most people consume 70 per cent more protein than they need. This may be true for non-athletes, but it could be misleading for cyclists. Having investigated protein intake for a previous CW feature, I know the recommended daily intake for athletes is 1.2-1.8g per kilo of bodyweight per day; I also know my own intake, when I measured it, was at the lower end, only just inside this range. 

As a vegan athlete, getting enough protein requires a conscious effort to eat the right things in appropriate quantities. Addressing this point, Wilks claims a peanut butter sandwich contains as much protein as a 3oz piece of beef. For that to be true, the serving of peanut butter would have to be enormous – four tablespoons, or almost one-third of a standard size pot! As a less calorific alternative, you could eat 240g of cooked lentils, but that’s a very large portion of a bulky, not especially appetising food. “It’s true that a vegan can compensate by eating bigger quantities [of protein-rich plant foods],” conceded Jeukendrup, “but the practical implication is that the volumes required are large – for some athletes, this is a real challenge, and after a while they let their protein intake fall.” 

Failing to eat enough plant protein is one risk; another is that, because protein-rich plant foods tend to be very filling, eating lots of them might cause you to eat fewer calories overall – potentially under-fuelling your training. Of course, this is not an insurmountable problem; provided you eat plenty of easily digestible carb-rich foods (alongside your protein), then getting sufficient calories need not be difficult. On the flipside, for riders keen to lose weight, the filling nature of protein-heavy plant foods, allowing a reduction in calories without an increase in hunger, is a clear bonus. 

What do pro riders think?

In a recent video interview for CW’s website, the Great Britain Cycling Team chef Alan Murchison – who has experimented with veganism in his own training – made the important point that performance advances tend to be driven from the top down. That is to say, if an innovation is proven effective, those at the top of the sport respond quickest in adopting it. This hasn’t happened with veganism; on the contrary, it’s a trend driven largely by environmentalists and social media influencers for whom performance is a secondary consideration after image, brand and lifestyle. Murchison recounts asking TT world champion Rohan Dennis his opinion on veganism and getting the terse response: “Vegan food is s**t. Next question.” The well connected chef reminds us that Dennis, as a man who demonstrated willingness to sacrifice his WorldTour contract rather than compromise on equipment, would never dismiss any dietary change that had genuine potential to make him faster. 

Nonetheless, CW did manage to find two WorldTour pros who are committed vegans and who believe going plant-based has benefited their riding: Simon Geschke and Adam Hansen, both vastly experienced riders with Grand Tour stage wins under the belts. “I went vegan in 2016,” Geschke told me. “I had a knee injury at the time and had heard that a vegan diet could aid recovery, so I was pretty excited to try it.” The German explained he phased out animal products gradually over many months before resolving to remain fully vegan. Did he perceive a benefit to his recovery? “Yes, I did actually, and [the knee problem] never came back. I can’t be 100 per cent certain [it played a part] but I felt good, so kept it up.” The diet choice has the blessing of his Team CCC coach and nutritionist – their support bolstered by his medical reports. “When I came to the team last year, I didn’t say I was eating vegan but the team doctor, on seeing my blood values, noticed I had the lowest cholesterol of the whole team and immediately guessed I didn’t eat meat,” added Geschke. “He made the deduction based solely on those results, which was pretty funny.” 

Blood biomarkers were also involved in Adam Hansen’s switch to veganism – he went wholly plant-based three years ago. “I just wanted to improve every marker in my blood group test,” he told me by email. “So I was cutting out food groups until I had better results – after a few months, I realised I had slowly become a vegan.” Explaining those biomarker changes, he continued: “I have noticed a huge drop in my white blood cell count [owing to less] inflammation from not eating toxic foods.” The technically minded Australian – who during the lockdown has been 3D-printing masks for local hospitals – takes a deep interest in the science of nutrition. Though he doesn’t take iron or B12 supplements, he does keep a close eye on his blood profile. It’s this attention to detail that might prove impractical for a regular amateur rider trying to follow a vegan diet. Would Hansen encourage us all to make the switch? “I don’t preach about it,” he responded. “People can do what they wish, it’s their health. The reason why I label myself as a vegan is because I want to show the people who might want to switch... that it is very well possible.” On the question of why so few pros are vegan, Hansen cited a more subtle shift: “I see a lot of pros making better food choices [and] reducing animal product intake, usually for health reasons.” For many riders, it’s quite literally a question of taste. “A lot of guys tell me they just can’t [go vegan] because they would miss cheese or other favourite dishes... they are favouring their taste over their health and an animal’s life.” 

Do vegans need to take supplements? 

When I told Jeukendrup I’d spoken to two vegan pro riders who had referred to positive changes to their blood profile, he countered with his own experience implying the opposite outcome. “Of those athletes I see with [suboptimal] abnormalities in their blood profile, most of them are vegetarian or vegan,” said the nutritionist. “It is usually iron deficiency.” Would he advise against veganism on these grounds? “If you really want to do it and you’re prepared to read up really well so that you know for certain what you’re doing, then fine – it can be done. But it is more risky, and this is why I see more [vegan] athletes with problems.” 

Another expert who has serious reservations about veganism among cyclists is sports endocrinologist Dr Nicky Keay. In her work with sports dietitian Renee McGregor, Keay has observed a troubling correlation between veganism and disordered eating. “My concerns about any athlete becoming a vegan is based on my clinical experience,” explained Keay. “From these medical experiences, I believe veganism can restrict dietary intake and hence put you at risk of having low energy levels. This is purely a clinical point of view.” Keay understands the demands of competitive cycling – her son is a coach and cat-one racer – and is acutely aware that the pursuit of ever-improving ‘watts-per-kilo’ can sometimes tip over into an unhealthy relationship with food – with veganism sometimes adopted as a disguised weight loss ploy. “For a cyclist who is already lean, reducing calorie intake via veganism is a risk to health and performance,” she warned. “It is challenging to meet energy and requirements through plantbased food alone, and besides, you will need supplementation.” 

Supplementation is a key issue for Jeukendrup too. “Iron deficiency stands out as the big issue for vegans,” he said. “It is a big issue in cyclists anyway because it has such an important impact on performance.” It must be noted here that iron deficiency, though more common in vegetarians and vegans, is not solely determined by diet – and there are many good plant sources. Even so, from a performance perspective, anything that raises the risk of deficiency must be taken seriously. “People have to realise [veganism] is not a diet you can follow without taking supplements – which, for me, immediately raises questions,” Jeukendrup added. “If you cannot follow a particular diet without taking additional supplements to be healthy, then is that a healthy diet?” 

It’s a provocative and important question. The counter-argument made in The Game Changers is that vitamin B12 deficiency does not affect only vegans – some meat eaters, albeit a minority, also fail to get enough from their diet. The same is true of vitamin D, which is scarce in natural foods and must be obtained from exposure to sunlight and, during winter, supplementation (recommended for everyone). All roads in the ‘veganism for cyclists’ debate seem to lead back to the same conclusion: it’s a diet that can support high performance provided you’re clued-up and meticulous, consistently eating the right amounts of the right foods. For some riders, summoning that extra diligence is a chore too far – life feels complicated enough already. The smörgåsbord of audacious claims made in The Game Changers – promising a slashed risk of cancer, bench press PBs, bigger erections, and all the rest – relies on cherry-picked research and writes a much bigger ‘gains’ cheque than the current scientific consensus can cash. Far more research is needed before we know for certain how much, if at all, ditching animal products benefits sporting performance.

Cost versus benefit

There is, however, one line of argument in The Game Changers that cannot be refuted: going vegan benefits the environment. A study in the journal Science found that livestock farming uses 83 per cent of all farmland but supplies only 18 per cent of the calories we need globally, while one-third of arable land is used to grow fodder for animals. It cannot be denied, therefore, that farming animals for food is catastrophically inefficient. Sure, we could improve farming methods, but it may be too late for such piecemeal action – climate change won’t wait. For Hansen, the key question on veganism is, what have you got to lose? “If you followed a vegan diet and the [claimed performance benefits] turned out to be wrong, you would have just followed a healthy diet and helped the environment.” It is a fair point: veganism might not make you faster, but provided you’re sensible, it’s unlikely to do you any harm. Though he hasn’t watched The Game Changers, the Lotto-Soudal pro is glad for the momentum it has added to the conversation. “I just hope these documentaries make people think twice about their judgments and the impact that they are having on the world,” he concluded his email, “then maybe they’ll reduce their intake [of animal products], for their own good and for the future of our planet.”

This feature was originally published in the 23 April 2020 print edition of Cycling Weekly magazine. Subscribe online and get the magazine delivered to your door every week.