Last updated July 19, 2018 at 10:26 am
Few sports rely so heavily on an exact balance between physiology, psychology and nutrition as cycling, making scientists some of the most critical members of the team.
He hit the lower slopes of the venerable Mont Ventoux, pushing hard. Tom Simpson, one of Britain’s most successful cyclists, had been battling illness for three days but was still determined to push for a good result at the 1967 Tour de France – and Ventoux is the climb that separates the contenders from the pretenders.
The day was hot, damn hot, and Simpson had looked tired before the 211 kilometre stage had even begun. “It’s not the heat, it’s the Tour,” he told a journalist enquiring about his exhaustion.
As the race climbed up the brutal slopes Simpson was riding well, staying in the front group with the other contenders for the general classification while the race fractured around them. As the elite group reached the upper slopes, Simpson slipped back, trailing by around a minute.
He then began to lose control of his riding, zig-zagging across the road – a sure sign of a cyclist in distress.
Around a kilometre from the summit, Simpson tumbled from his bike. His support crew rushed to assist, lifting him back upright. They implored him to stop, telling him his race was done, he was done. But Simpson wasn’t having a bar of that and insisted on keeping going.
Around 500 metres later Simpson was over again, spectators rushing to help. They and his team laid his lifeless body next to the road, where a mechanic had to pry the bike’s handlebars from his locked hands.
A team mechanic and Tour nurse took turns giving mouth-to-mouth resuscitation until, some 40 minutes later, Simpson was airlifted to a nearby hospital where he was pronounced dead.
He had pushed himself to the point where he died on his bicycle.
The memorial to Tom Simpson near the summit of Mont Ventoux. Image credit: Peter Curbishley/Flickr
Professional cyclists sometimes seem like they’re a different breed of human. The ability to push themselves near to their maximum ability for hours on end, withstanding pain, exhaustion and their own minds, is one of the most impressive sights in sport. And then they jump back on to do the same the next day, and then another, and then another.
A Grand Tour such as the Tour de France has been likened to running a marathon every day for three weeks. Even shorter tours like the six-day Tour Down Under in Adelaide are brutal tests of some of the fittest athletes on the planet.
With such intense physical demands, and psychological, it is perhaps understandable why some resort to using performance enhancing drugs.
In a post-mortem, Simpson had been found to have amphetamines and alcohol in his system to keep pushing himself to beyond his limits.
But even without drugs – and the sport has cleaned itself up significantly – the cyclists we see on the roads at the Tour Down Under are absolute physiological and psychological rarities.
Physiology
The professional rider’s body is less ‘human’, more ‘finely tuned racing engine’. Every part of a rider’s physiology is precisely honed in order to get them across distances, up mountains or bursting to the line at maximum speed.
Looking at an elite cyclist, one of the first things you notice is the apparent complete absence of body fat. On average, male elite cyclists in a study were measured to have around 4.7% body fat, compared to a normal average male of around 20-25%. Just like a racing car, the less weight you need to pull, the faster you’ll be.
There is a definite period before and during races where cyclists become super-lean, too. In the three weeks following his win at the 2015 Tour de France, Chris Froome added around 4 kg of body weight and saw his body fat balloon to 9.5%.
Sprinter Mark Cavendish, who claims to generate 1,580 Watts in a sprint. Credit William Morice/Wikimedia Commons
The amount of power a cyclist can generate is one of the key indicators of their speed. Froome, as a champion all-rounder and time trialist, had a maximum power output of 525 Watts, significantly more than the 400W an average person would be able to hit. A specialist sprinter, however, is capable of even more. Training solely for a 10-15 second burst of speed where they can hit speeds well over 60 kilometres an hour, elite sprinters have on average a maximum power output of around 1,250W, and will average around 1,100W for the duration of the sprint. Mark Cavendish, the most successful sprinter in Tour de France history, has claimed to hit around 1,580W.
Compared to his weight, Froome is capable of around 7.5 Watts per kilogram of body weight, but that was calculated at his higher post-race weight. At racing weight it is conceivable his power-to-body-weight ratio is even higher. On race days it would be expected a GC contender to be pulling around 6W/kg for 45 minutes through the mountains, a rider attacking to break away from the peloton to pull 8W/kg with maximum attacks at around 15W/kg, and around 18W/kg by the sprinters over the last 10 seconds of a stage.
One of other the factors which dictates an athlete’s ability to maintain high levels of performance is the VO2peak – the maximum amount of oxygen their body can consume. For Froome, his body can suck in 84ml of oxygen per kilogram of body weight every minute, far above an average person whose numbers are around 60ml.
Chris Froome at the 2016 Tour de France. Credit: Filip Bossuyt/Wikimedia Commons
The VO2peak is another measurement where we see differences between riders of different specialities. Using riders not quite of Froome’s standing, climbers averaged around 78ml/kg per minute, while flat terrain riders had lower levels of around 72 ml/kg per minute.
When combined with power output, this starts building a picture of Froome’s ability to remain at a high speed for a significantly long time, and just why he has been so successful against other riders.
Froome’s freakishness becomes even more apparent, however, when he needs to perform in hot conditions. His reputation in races is of someone who excels in hot weather, carrying on when others wilt. To find out, physiologists put him to the test in hot humid conditions – 30°C and 60% humidity. Compared to his performance at ambient temperatures, Froome didn’t fade – in fact he seemed to find another gear.
When it came to his maximum power at a particular level of lactic acid production (4mmol per litre of blood, about the level produced during a time trail stage or mountain stage), Froome was capable of maintaining higher power outputs at hot temperatures than ambient (430W vs 419W).
Similarly, his gross efficiency – the percentage of total energy expended that translates into external work, improves under hot conditions (23.6 per cent vs 23 per cent).
Usually a paradox exists between gross efficiency and VO2peak – comparing athletes usually one value will be high and the other low. It has been hypothesised that a high efficiency might compensate for a relatively low VO2peak. Froome, however, has high results for both, uncommon amongst elite athletes.
Now, see how retired professional Pat Jonker stacks up after years out of the peloton:
Nutrition
To fuel the engine, professional cyclists have immense dietary requirements.
The average Tour de France rider needs to eat anywhere from 5,000 to 8,000 calories per day – far above the recommended daily intake for a male of 2,000-2,500. This huge intake is just to load up and replenish what they use on the bike. In 1988 riders were found to be expending around 6,000 calories of energy every day.
An elite race requires a lot of fuel. Credit Felouch Kotek/Wikimedia Commons
However to reach those levels of intake it’s not just a free for all at the hotel buffet. Everything a professional cyclist eats is designed to meet a strict criteria of carbohydrate, protein and nutrient content.
Although it seems like a high fat diet would be a good source of energy for cyclists, this is not strictly true. While fat does contain more energy per gram that carbohydrate or protein, for endurance events the body prefers to utilise carbohydrate as an energy source. As the race intensity increases, so does the preference for carbs. When those carbs, which are stored mainly as liver glycogen, start running low performance will drop rapidly.
The energy source being used by the body is never only one or another, but is a mix between all sources available, which makes it important to keep a correct ratio in the diet. As a rough starting point, some nutritionists suggest a 60:20:20 ratio – 60 per cent carbohydrate, 20 per cent protein and 20 per cent fat. However, these are tweaked depending on the athlete, their role in the team, and other dietary factors.
In practice, this can mean five to 12 grams of carbohydrate per kg of body weight, and one or two grams of protein per kilogram of body weight (for muscle recovery and repair). Fats are still considered essential to an athlete, however with a focus on polyunsaturated fats and oils.
One of the more incongruous sights at multi-stage cycling races is seeing a professional team the evening after a stage walking out of an ice cream shop. However the carb, fat and protein mixture of ice cream would likely not be a world away from the profile of a cyclist’s diet.
Plus, everyone deserves a treat sometimes.
Somewhat surprisingly, a number of sports nutritionists told us one of the best recovery drinks is flavoured milk. Milk contains a good amount of protein and fat, plus is hydrating. Add the sugar that inevitably gets added into flavoured milk, and you’ve got the components required to recover from strenuous exercise.
So is one flavour better than the others? No, although most athletes who had worked with the nutritionists we talked to preferred chocolate.
Thor Hushovd at the 2011 Tour de France carrying a musette. Credit Global Ref/Wikimedia Commons
While the rider is on the bike itself they still need to consume carbohydrate in order to keep their glycogen levels raised. For that, each team prepares a musette – a tote bag full of goodies handed out to riders during the stage. The contents of a musette can range from drink bottles and bananas, to sandwiches (more on that in the video below) and energy gels, bars, and chews.
The gel sachets come in both caffeinated and non-caffeinated form, and usually contain around 20-25 grams of carbohydrate as well as salts such as sodium and potassium, which the manufacturers recommend eating every 30-45 minutes during the race itself.
Some taste ok, others are plain bad.
A cyclist can eat a perfectly crafted diet, but if they don’t hydrate properly, all their work will be for nothing.
According to British Cycling, only a surprisingly small level of dehydration is needed to start affecting performance. A two per cent drop in body weight due to sweating impairs performance, while a four per cent drop will see significant changes in your muscles ability to produce power.
Team staff handing out drink bottles at a feed station. Credit Flowizm/Flickr
For an elite cyclist, avoiding these drop offs requires drinking an ungodly amount of liquid – at the 1988 Tour de France the riders were drinking around 6.7 litres per day during a race, with one cyclist drinking nearly 12 litres.
More than 60 per cent of their hydration was consumed while on the bike itself.
Sports drinks have major advantages over water when it comes to rehydration, delivering required salts including those of sodium, potassium and magnesium, and nutrients including carbohydrate to help meet energy requirements. However, Sports Dietitians Australia suggest that drinking plain water while eating salty food such as crackers can be just as effective as consuming a sports drink. Additionally, it is not necessary (or practical) to replace all fluid losses during the race itself, so they recommend targeting to replace 150 per cent of the fluid lost over the four to six hours following a stage.
It is possible to overdo it, however, especially when drinking plain water. Without added electrolytes water can essentially dilute the fluids in your body, leading to a feeling of being bloated which affects hydration later in the race. In extreme cases, which has happened to marathon runners, the dilution can lead to hyponatremia, or a too-low concentration of salts in the body. If hyponatremia gets out of hand, it can lead to death. To avoid this situation electrolyte balance during rehydration is closely monitored.
On any given weekend there is the regular sight of cyclists hanging out at a local café, enjoying a post (or mid) ride espresso. And for the pros the love of coffee is usually just as strong. Not only does caffeine increase alertness, but it can actually make the same level of exertion seem slightly easier. And as an added bonus, a study found that cyclists who teamed up drinking caffeine with their carb intake also accumulated 66 per cent more muscle glycogen (the main fuel for working muscles) than when they ate only the carbs.
Now, watch Pat Jonker chat with sports nutritionist Evangeline Mantzioris, and try out one of Team Sky’s special concoctions from their musette:
Psychology
Like any endurance athlete, professional cyclists are psychologically fascinating.
Watching them on television, or from the side of the road, an everyday person has to wonder how they mentally keep going through the pain and pressure, torturing themselves physically over mountains and in sprints, when realistically only a handful will ever be in a position to take a big win.
Distractions at the Tour de France can come in unexpected forms
It is probably not surprising that developing an intense focus plays a large part of a rider’s mindset, creating their own “zone.” Staying in that zone is vital. If they become distracted, their performance can suffer and they start to crack.
Dr Harbinder Sandhu from Warwick University in the UK has mentored Olympic athletes on how to keep their mind on the task. “To keep focused athletes can employ techniques like mindfulness or being aware of the body (doing a body scan, to become aware of any tension, focusing on breathing and connecting the mind, body and bike).”
Being able to pull their thoughts back from those distractions or negative thoughts on to more performance enhancing related thoughts is a critical step in unlocking an athletes maximum performance, and preventing thoughts building to a point where their physical performance suffers.
“Tension and anxiety can impact on physical ability, so remembering to breathe, relax and getting into the mind set before a competition is important. Solo riding during a tour can be testing mentally as well as physically. Being able to manage your thoughts, a wandering mind, fear and anxiety are all important,” says Sandhu.
Luke Henderson, a psychologist who has worked with elite athletes of several sports, including cycling, encourages his riders to “worship” the journey and focus on the process of growing and improving, rather than focussing too much on the outcome. Elite athletes, he says, can recognise the satisfaction of just trying their hardest.
Similarly, an elite cyclist will often have a different interpretation of their performance – looking for opportunities to grow and shift their focus to what they can learn to be able to improve for the next race.
Vincenzo Nibali (front) battling Nairo Quintana (behind) during a climb. Credit Sanguinez/Wikimedia Commons
Elite cyclists will also quite often show a minor perfectionist streak, which helps feed that improvement mindset.
The team structure is a strong motivator when things get tough. To a professional cyclist, even a domestique (a rider in a team whose job it is to protect the team leader or specialists, sacrifice themselves to attack other teams, and do menial tasks like fetching drink bottles for other team members), being part of that team is a massive motivator. A former professional rider, who then went on to be a director of a team, commented that the other riders are your mates, and the last thing you ever want to do is let them down. You have a job to do, and you have to complete that job no matter what, or else you’ve let everyone else in the team down.
There is also the promise of future opportunities if a rider can prove themselves as a dedicated and capable lieutenant. One day the team might elevate you from domestique to a leadership role, and then other riders will be working for your benefit. That dedication was a big motivator to dig deep when things started falling apart for a number of former professionals.
There is a different motivation at play as well though. “This was my job, I didn’t really enjoy it, but it’s how I made a living,” one high-profile former professional cyclist told us. It is a sentiment hinted at by others we have talked to as well.
It’s thought this was a factor in Tom Simpson’s death as well. Having been professional for 8 years, he was motivated to earn as much money as he could from the sport before retiring. A good finish at that year’s Tour de France would boost his income after the race, which fuelled his reluctance to withdraw due to his ill health.
Retired professional cyclist Pat Jonker gets put under the microscope by elite-sports psychologist Emma Mattey, who finds out exactly what drives Pat’s will to win.
Drugs
It is however, the scourge of the sport that it has been so inextricably linked with performance enhancing drugs. In a sport where just a few percent is the difference between winning and not being close, combined with the intense psychological pressures, drugs were sure to rear their ugly head.
In the early days of the sport and through to Simpson’s era in the 1960s, cyclists used stimulants such as cocaine and amphetamines to overcome the feelings of fatigue and push themselves to their absolute limits. But in the 1970s, the focus switched to artificially increasing the limits of the body itself, with drugs such as steroids increasing strength and reducing recovery time.
The biggest change, however, happened with the introduction of erythropoietin, or EPO. A naturally occurring hormone secreted by the kidneys, EPO stimulates the bone marrow to produce red blood cells. This in turn increases the oxygen carrying capacity of blood, improving muscular endurance, reducing fatigue, and potentially improving recovery times.
Artificial EPO supplements were developed in the 1980s to help people with kidney disease who suffered from anaemia, and has since been used by cancer and HIV patients as well. With its ability to boost red blood cell counts, however, it was quickly picked up by professional cyclists to boost endurance.
A further advantage to using EPO was that there was no test for it until the 2000 Olympics. Instead, until then, the rule-makers implemented a limit of 50 per cent haematocrit – that is, 50% of your blood could be made up of cells (the rest being plasma). More than 50 per cent, the authorities reasoned, was a probably sign of EPO use, but rather than facing a ban the cyclist was required to sit out 15 days, termed a “haematocrit holiday”. However, all this did was set a target for teams – use EPO to increase haematocrit levels to 49 to 49.5 per cent.
In one study published in the European Journal of Applied Physiology, EPO was found to increase peak power in amateur cyclists by 12 to15 per cent, and increase endurance by 80%. However, reanalysis of data from several studies has revealed that the effects of EPO may have been overestimated, and only translate to a 1km/h improvement on the road. While that may not sound like much, for a professional cyclist that would be about a two per cent improvement, by itself potentially enough to lift them up the rankings. EPO would, however, also allow that faster speed to be held for longer.
Disgraced champion Lance Armstrong. Credit Velocia/Flickr
Taking EPO is not without risks – increasing red blood cells levels thickens the blood and can lead to heart attacks and strokes. Indeed, a series of deaths amongst Dutch and Belgian riders in the years around 1990 is thought to be linked with EPO usage, to the point where riders would set alarms for the middle of the night to wake up and do some pulse-increasing exercises.
The other method for increasing red blood cells is by blood transfusions – putting more red blood cells back into the body. During training, around a litre of blood would be taken from the athlete, and then centrifuged to separate the plasma from the red blood cells. The plasma would be put back into the athlete (encouraging the kidneys to signal for increased red blood cell production to bring it back to usual levels), and the red blood cells frozen until required. Then, before competition or during a multi-stage race such as the Tour de France, the red blood cells are transfused back into the athlete, boosting levels and giving the athlete the advantages of high haematocrit levels.
Without a chemical stimulant such as EPO, and using the athlete’s own blood as a source, transfusions were difficult to detect other than monitoring haematocrit levels for sudden changes. This difficulty in detection, and perceived safety of using their own blood products made transfusions a popular method of blood doping in the early 2000s following the introduction of EPO tests.
Another common performance enhancing drug was testosterone. Naturally produced by the testes, a large dose of testosterone can significantly increase a person’s strength and muscle mass. In addition there are other anabolic steroids that have been used to build muscle mass, and growth hormones.
Recently, there have been several cyclists fall foul of drug tests for salbutamol – the active ingredient in asthma puffers. This includes, to the shock of many, Chris Froome.
Salbutamol belongs to a family of drugs called Beta-2 agonists, which work by relaxing the muscles in the airways leading to the lungs, making it easier to breathe. The benefits are obvious for asthmatics, and some may think that endurance athletes could also benefit as it would, in theory, allow more oxygen to be taken in. However, there is no evidence that there is a performance benefit when inhaled by non-asthmatic athletes.
Athletes are allowed to use salbutamol inhalers after receiving a therapeutic use exemption – an approval to use the drug based on a genuine medical need. And Froome, like a surprising number of endurance athletes, is asthmatic. However, in his case, the salbutamol levels were found to be twice the allowable limit. (Scandalously, Froome’s results had appeared to be kept secret by his team and the UCI, and only came to light after investigations by The Guardian and Le Monde newspapers).
In the past, even when tests for these drugs have existed, some of the testing regimes have been lax to the point where cyclists were confident in their ability to dodge them. It was still a risk, but with preparation and a minor amount of planning, it sometimes became ludicrously straightforward to beat an out-of-competition test.
Former professional rider Tyler Hamilton. Credit fsteele770/Flickr
Writing in The Secret Race, former professional and teammate to Lance Armstrong, Tyler Hamilton, revealed some of the ways he avoided testing if he was likely to return a positive test. Living in the Spanish town Girona, the drug testing agencies would only send one tester out for the “surprise” tests of all the cyclists in town.
“Whoever got tested first immediately phoned his friends to tell them. Word got around fast. So if you happened to be glowing, you could take evasive measures.”
In some cases those evasive measures were ridiculously childish. On at least one occasion Hamilton and his partner laid on the floor of their kitchen to hide from an unannounced drug tester knocking at the door. That bought a day before the tester came back for Hamilton to drink, pee and bring his drug levels down. In another case, an older gentleman who administered the tests would ring the night before to ask whether Hamilton would be at his home in Girona the next day so that he didn’t waste the trip from Barcelona.
However, the game has changed. There have been some high profile setbacks along the way – George Hincapie, Stuart O’Grady and Lance Armstrong’s revelations spring to mind – but credibility seems to be returning to the sport. Cleaning up the act has required a complete rethink of drug testing.
Previously testing comprised of analysing urine samples for metabolites of performance enhancing drugs, but that required the drug testers to know what drugs the cyclists were taking, and how they were taking them. It also allowed clever approaches to drug-taking to ensure that tests would stay clean, even if the athlete wasn’t.
Recently, however, there has been a shift in thinking. What if, rather than testing for the drugs, you tested for the outcome of the drugs? In a nutshell, that is the ideal behind the Biological Passport.
The Athlete Biological Passport (ABP) is a long-term record that monitors selected variables, nicknamed ‘biomarkers of doping’, that indirectly reveal the effect of doping. Should any of those biomarkers change it would indicate a shift in the cyclist’s physiology that could be as a result of drugs. The actual drug doesn’t necessarily need to be detected, however the physiological effects caused would give away its use.
According to the World Anti-Doping Agency’s website, the ABP comes in two parts:
- The Haematological Module, introduced in December 2009, aims to identify enhancement of oxygen transport, including use of erythropoiesis-stimulating agents (ESAs) and any form of blood transfusion or manipulation.
- The Steroidal Module, introduced in 2014, aims to identify endogenous anabolic androgenic steroids (EAAS) when administered exogenously (i.e. not created by the human body) and other anabolic agents, such as selective androgen receptor modulators (SARMS).
The Australian Sports Anti-Doping Agency (ASADA) introduced the Haematological Module of the ABP in 2012, some three years after its implementation by WADA. The Steroidal Module was implemented by both agencies simultaneously.
The ABP is not seen as a replacement for traditional drugs testing, but as an extra layer of control. Often changes in the passport may be used to help target athletes for more intensive testing, and combining traditional testing results and the ABP with non-analytical doping violations, is seen as a more effective strategy to weeding out the cheats.
Some experts have raised concerns about how the ABP is used.
Jonathon Tiernan-Locke, who was suspended following abnormal results in his ABP. Credit Peter Edmondson/Wikimedia Commons
In the case of UK cyclist Jonathan Tiernan-Locke, who was sanctioned for two years over questionable ABP blood results, a haematologist backed up his defence that a night of heavy drinking could throw blood results out of normal ranges. Tiernan-Locke was banned seemingly on the basis of a single abnormal result (in fact the first result entered in his passport, which subsequently didn’t match following tests), that could have suggested a massive dose of EPO. However, there was no other evidence to back up that charge. Tiernan-Locke’s story, backed by the haematologist, of a hard night of celebration following a race win was thrown out.
Dutch analytical chemist Klaas Faber has also raised questions as to how the ABP is used. In 2009 he was an author on a report critical of the way blood values were being interpreted. In 2014, not long after Tiernan-Locke was suspended, he reiterated his concerns.
“Forensic scientists (in criminal cases) use a strong statistical model to evaluate the evidence, but anti-doping scientists have been improvising since the start,” he told the BBC.
Indeed, most external experts, and coaches and athletes believe the ABP is an excellent tool for increasing targeted testing of athletes. But on it being the sole evidence, and especially on a single spurious result, they’re not so sure.
There are also concerns that the ABP can still be defeated by micro-dosing of drugs such as testosterone and EPO – taking very small doses often. This reduces the chances of testing positive for the drug due to the lower levels, and reduces the risk of sudden wild changes in an athlete’s ABP. “Is the passport too blunt a tool to deal with that?” asks Team Sky principal Sir David Brailsford, who was Tiernan-Locke’s boss at the time of his spurious result.
On the positive side, the ABP has definitely stopped blatant drug taking and transfusions, and it is a very powerful tool, but the use and interpretation of the results needs to be handled with care.
At its best, cycling is one of the most incredible sports to watch. Athletes pushing themselves to their absolute maximum, pain etched across their faces, the demons inside their minds at battle. There are few other sports where science has lifted the performance of an athlete to such extreme levels, and sometimes, unfortunately, artificially beyond.
From maximising their physiological capability, to preparing their mind for the pressure, and making sure they’re fuelled up to go, sports scientists are some of the most critical members on a professional cycling team.
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