Weight-loss drugs, such as Ozempic and Wegovy, have seen people lose more than 15 per cent of their body weight and Walmart has attributed a drop in food sales to their invention and market rollout. As a result, many have labelled this new generation of drugs as a societal ‘game changer’.
You can see why. The World Health Organisation says 2.5 billion adults are overweight (a BMI of 25 or over) or obese (BMI over 30), with this figure predicted to tip to over 50 per cent of the world’s population by 2035. In a clinical setting, these drugs promise to cure the first-world obesity pandemic and its associated diseases. But what about a performance setting?
Cycling is a weight-based sport, leading us to predict that teams and riders are already digging deep into the research to see how these weight-loss drugs could fit into their nutritional arsenal.
It’s not as if cycling’s immune from using drugs for therapeutic means for faster cycling. Think of testosterone, growth hormone and EPO. Here, we dig into the issues at play, starting with an explainer of how these drugs work.
Suppressing hunger
“Both Ozempic and Wegovy are produced by Danish company Novo Nordisk, and whose active ingredient is ‘semaglutide’,” says David Stensel, professor of exercise metabolism at Loughborough University. He’s also editor-in-chief of the International Journal of Obesity.
“Ozempic’s prescribed for diabetes, while Wegovy’s a higher dose and is prescribed for weight loss in obese individuals.
“How it works is down to semaglutides, which belong to a class of medications known as glucagon-like-peptide-1 (GLP-1) receptor agonists.
"These receptors help to increase the release of insulin, which then lowers blood glucose. Hence, its prescription for type-2 diabetics. But it became evident that another action of GLP1 is to suppress hunger and appetite by acting centrally on the brain, leading to these quite staggering weight-loss stories.”
Vis-à-vis the 15.2 per cent weight-loss figure from Novo Nordisk’s studies, that equated to around 15.9kg for most of the participants. That was a couple of kilograms under Elon Musk’s dramatic 13.6kg weight loss, which he revealed on X in November 2022 and, for many, was the first time they’d heard about Ozempic and Wegovy.
Further weight-loss drugs have hit the market including tirzepatide, which is sold under the brand names Mounjaro and Zepbound. And then there’s liraglutide, sold as Victoza and Saxenda.
Saxenda and Wegovy are currently the two brands prescribed by the NHS for weight-loss purposes with Saxenda injected once a day and Wegovy once a week (professional cycling has a no-needle policy, but pill alternatives have just hit the market).
Viewed through a health lens, you might be able to see why these drugs are being called ‘game changers’. Through a cycling lens, could the results be similarly transformative?
Boosting power-to-weight ratio
Power-to-weight ratio is a key performance metric for climbing. If the left-hand side of the equation’s high and the right’s low, you’ll fly. Now, let’s see how semaglutides could impact this ratio.
Strava’s fastest registered time for ascending the 13.8km, 21-hairpin monster that is Alpe d’Huez is Sepp Kuss’ 39:21mins at the 2022 Tour de France, the stage won by Tom Pidcock that included his legendary Galibier downhill masterclass.
Now, let’s use our imaginary rider, Matthew Smith, as a semaglutide guinea pig. Smith weighs 68kg. If the mighty Smith tames Alpe d’Huez with a power output of 307 watts, equating to a power-to-weight ratio of 4.5w/kg, it’d take him 50:28mins.
But if performance-seeking Smith took semaglutides and lost 15 per cent of his bodyweight, he’d drop to 57.8kg, cranking up power-to-weight to 5.3w/kg and chiselling that time down to 44:51mins – a near-6min saving.
Okay doctor, sign me up. Not so fast. We confess our imaginary 15 per cent lighter Smith's climbing performance is a flawed comparison, primarily because of that significant weight loss. In the trials thus far, many of the individuals hitting the figure started from a benchmark of over 100kg.
Recreational cyclists are generally well under that figure, especially those at the peak of the amateur competitive pyramid, so wouldn’t experience anywhere near those losses. Still, that’s not to say a 68kg rider such as Smith wouldn’t lose weight using these types of drugs and so gain a competitive edge, but as it stands, there’s a complete lack of literature looking at semaglutides in a sporting context. And with good reason, says Stensel.
“I don’t think a drug designed for people with obesity or co-morbidities like diabetes would get past an ethics committee,” he says. “All of the trials have been done on people of a BMI at least 30 and often much higher.”
That’s not to say it won’t happen down the line because we’re certainly aware of studies into the performance gain delivered by EPO, designed to treat severe anaemia. Still, if athletes were to experiment with these weight-loss drugs, they’d have to bypass doctors and chemists who can only prescribe for therapeutic reasons.
WADA’s monitoring list
Still, as we know, many a rider – both elite and amateur – follows a rather erratic moral compass. But, as it stands, semaglutide is not illegal. We contacted WADA (the World Anti-Doping Agency) to ascertain its status for 2024 and they replied: “Ozempic (semaglutide) is not a prohibited substance. However, it is on the 2024 Monitoring Program in order to detect potential patterns of misuse in sport.”
Interestingly, this programme also includes everyday substances such as caffeine and nicotine, for in-competition monitoring.
Whether a substance is ‘promoted’ from the monitored list to the banned list – such as tramadol, that’s been banned in competition since 1 January 2024 – it must satisfy any two of the following criteria: it has the potential to enhance or enhances sport performance; it represents an actual or potential health risk to the athlete; and it violates the spirit of the sport. As it stands, you could argue taking a semaglutide would violate the spirit of the sport. But the other two? It’s too early to say.
Stencil explains. “That weight loss includes fat-free mass, in other words muscle mass,” he says, which can account for up to a third of the drop. “In obese individuals, arguably that’s not the end of the world because it’s almost a training response to moving a large body around. And if you’ve lost a lot of fat mass, you don’t need such big leg muscles. In sportsmen, though, clearly that’s not ideal.”
Also, while its appetite-suppression attributes are good to lose weight, they’re not great if you’re burning through several thousand calories a day. You need calories to repair and grow your body, as well as bolster your immune system. If you’re not hungry, you’ll soon ride rough shod into overtraining and illness.
Then there’s the ‘potential risk to an athlete’. It’s early days and, as Stensel says, there have been no serious side-effects so far. “The most common are feeling sick, vomiting, diarrhoea, abdominal pain and constipation due to slowing gastric emptying because food stays in the system for longer.
“However, there is a long history of failed obesity drugs that have gone through extensive testing, been prescribed and subsequently been withdrawn.
"One reason why is that when you have drugs that are interfering and changing perceptions in the brain, it’s fine if they’re specific perceptions of hunger and food.
"But problems arise when they’re more general effects in the brain. I’ve known drugs in the past that were taken off the shelves because they left some users with suicidal feelings, while another resulted in heart valve problems and pulmonary hypertension.
"But I must stress there’s no evidence of any of this with this batch of weight-loss drugs and I can see why they’re being called ‘gamechangers’.”
But, concludes Stensel, not for performance reasons. “There are two final reasons why cyclists should look elsewhere. The first is that there’s a small risk of hypoglycaemia. This is low blood sugar levels, which is the last thing cyclists need. There’s also the ethical issue that there are supply issues, so they really need to be reserved and used for the people who really need them. These drugs can really change the lives of those battling with obesity.”
