Authors: Karsten Øvretveit¹

Corresponding Author:

K.G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, Norwegian University of Science and Technology,
Trondheim, Norway, PB 8905, N-7491 Trondheim, Norway
[email protected]

Karsten Øvretveit, MSc3, is a physiologist and PhD candidate at the Norwegian University of Science and Technology (NTNU). His research areas include genetic disease risk, physical performance, motivational dynamics, and human nutrition.

Can there be two speeds in a clean peloton? Performance strategies in modern road cycling

ABSTRACT

In the history of professional cycling, riders have always sought competitive advantages. Throughout 20th century, many relied on performance-enhancing drugs (PEDs) which gave rise to a phenomenon called “two-speed cycling”. Throughout its modern era, professional cycling has seen anti-doping efforts repeatedly intensify on the heels of several large doping scandals. Over the past decade, the sport appears to have transitioned away from large-scale systematic doping and towards novel, legal performance-enhancing strategies, facilitated by a close relationship with scientific, technological, and engineering communities. The tools and technologies available to assess the demands of the sport, the capabilities of the riders, and the role of environmental factors such as wind resistance, altitude, and heat are more refined and comprehensive than ever. Teams and riders are now able to leverage these to improve training, recovery, equipment, race tactics and more, often from a very early age. This review explores several key developments in road cycling and their implications for the modern professional peloton.

Key Words: professional cycling; performance-enhancing drugs; marginal gains; performance analysis

INTRODUCTION

The main pack of riders navigating the road in a cycling race, known as the peloton, comprises a wide range of physiological, anthropometrical, technical, and strategical attributes. The role of each rider in a given race is typically based on strengths, weaknesses, and objectives, and can be modified by injuries, fitness level, personal goals, and unexpected in-race developments. The concept of “cycling at two speeds”, cyclisme à deux vitesses, has historically been used to distinguish between chemically enhanced riders and those who ride clean (134). However, despite increasingly stringent doping controls in professional cycling along with a clear shift in doping culture, the concept of two-speed cycling remains.
Given the well-documented benefits of performance-enhancing drugs (PEDs), there is an expectation that the intensification of anti-doping measures in professional cycling leads to more homogeneous performance levels in the peloton by reducing the number of artificially enhanced riders. Although this may be a reasonable assumption, it discounts the many substantial advances made in training, nutrition, technology, and strategy, as well as the growing talent pool of potential professionals and the early age at which they begin to seriously structure their training, racing, and recovery. These factors can differ greatly between teams and individual riders and thus help maintain the two-speed phenomenon. This review provides a brief history of the PED culture and use in professional cycling, followed by an examination of some of the key developments in the sport that has helped preserve the two-speed phenomenon in a peloton riding within an increasingly strict anti-doping framework.

The performance-enhanced past of the peloton

Drugs have been used to enhance athletic performance for millennia, stretching back to at least the ancient Olympic Games (16). Cycling as a profession emerged among working-class men who likened endurance sports to physically demanding jobs where the use of drugs to aid performance was considered the right thing to do (58). Indeed, doping has been pervasive in professional cycling for over 150 years, throughout most of which it was either legal or not subject to testing (34). For decades, riders doped to simply be able to do the job – faire le métier (33). Then, athlete health became a concern and a major driving force to regulate, if not outright ban the use of certain substances. Drug testing in the Tour de France (TdF), the most prestigious event on the race calendar, began in 1966. Despite this, amphetamines, cortisone, and steroids remained widespread in the professional peloton. It was also around this time that rumors about the use of blood transfusions in athletes began (60). The year after Raymond Poulidor underwent the first drug test in the TdF, Tom Simpson collapsed on the ascent of Mount Ventoux and later passed away due to an unfortunate combination of alcohol, amphetamines, intense heat, and extreme physical exertion. Although this event brought more attention to the use of stimulants and other drugs in cycling and in sports in general (69), doping would persist for decades to follow. Based on interviews with riders on a professional cycling team at the turn of the millennium, psychiatrist Jean-Christophe Seznec (115) asserted that professional cyclists are not only prone to develop an addiction to PEDs, but also recreational drugs, noting the importance of explicitly acknowledging this risk in order to mitigate it.

When professional cycling entered the 90s, the banned yet at that time undetectable erythropoiesis-stimulating agent (ESA) recombinant human erythropoietin (rHuEPO) arrived in the peloton (101), and performances hit a new level. Increasing circulating erythropoietin (EPO) by illegal means has been perceived by some riders and coaches to give an estimated performance boost, without the term “performance” being strictly defined, of 3% to 20% (31, 100, 134, 138). Interestingly, despite its popularity in the peloton, the research literature on the effects of ESAs such as rHuEPO on endurance performance is equivocal. Its effects on hematological values like hemoglobin concentration ([Hb]) and clinical measurements of power and maximal oxygen uptake (V̇O2max) are well-established, but the real-world benefits are not always clear (116, 123).

There are several aspects of professional cycling that are difficult to account for in experimental studies on exogenous EPO, such as the extremely high fitness level of a peaked professional cyclist and the physiological impact of training and racing on parameters such as Hb. A recent randomized controlled trial found no apparent benefit of EPO on relevant performance markers has sometimes been cited to shed doubt on the true effects of the drug (47). However, this study was done in cyclists with an average V̇O2max of 55.6 mL/kg/min, which is substantially lower than their professional counterparts (124). By his own account, former professional Michael Rasmussen saw his hematocrit (Hct) drop from 41% to 36% following the 2002 Giro d’Italia (98), illustrating how blood composition can be severely perturbed by training and racing. Similar values have been observed in other professionals following participation in Grand Tours (17, 89). Using Rasmussen as an example, using rHuEPO to bring this up to 49%, just below the old 50% limit, would represent a relative Hct increase of 36% and result in improved ability to maintain a much higher intensity in training and racing, and consequently greater exercise-induced adaptations.

Throughout the 90s, Grand Tour riders with supraphysiological Hct would traverse France, Italy, and Spain at impressive speeds until it all seemingly came to an end in 1998. Three days before the start of the 85th edition of the TdF, a Festina team car carrying various PEDs was stopped by customs agents at the French-Belgian border. This event marked the start of what later became known as the Festina affair, a major catalyst in cycling’s transition to a cleaner sport. The wake of this scandal saw an increasing number of calls to action against doping, including by the driver of the Festina car (132), with claims of the sport dying unless drastic action is taken. Subsequent large-scale doping cases such as Operación Puerto and the contents of the USADA’s Reasoned Decision Report (10) served as reminders that PEDs were still present in the peloton and strengthened the resolve of those fighting for a cleaner sport.
Although riders are often blamed for the pervasive drug use in cycling, most entered a sport with a lack of top-down anti-doping efforts, leaving them with the difficult choice of either conforming to the culture or competing on unequal terms. One of the most crucial steps towards a cleaner sport is a change in culture among teams and riders. Much, if not most, of the credit should go to the riders themselves, many of which have actively pushed against the use of PEDs for years (46, 50, 59, 85, 130). Today, most doping cases in cycling are among semi-professional riders, whereas the number of riders testing positive at the highest level is approaching zero (88).

Although absence of evidence is not evidence of absence, fewer doping cases at the highest level of cycling suggests that overt, systematic drug use is a thing of the past. Given professional cycling’s checkered history, it would be naïve to think that doping has been eliminated entirely, but the sport does appear to have evolved beyond doping being perceived as all but necessary to gain entry into the professional peloton. Generational shifts not only among riders, but also among governing bodies and team leadership have contributed to an overall firmer stance against doping, removing potentially significant contributors to anti-doping violations (6). There is also indications that the post-Armstrong generation, especially those who started their careers young, are less likely to use PEDs (5), although the evidence is equivocal (64). Additionally, anti-doping technology continues to improve, with recent advances such as gene expression analysis being able to extend the detection window of blood manipulations (28, 133).

Conceptual approaches to legal performance development

It could be argued that the extraordinary performances regularly being on display by the current generation of riders suggest that the dismantling of systematic doping practices has led to progression rather than regression of the sport of cycling. The transition away from prevalent PED use has forced teams and riders to seek out other areas of improvement, some with barely measurable effects, to keep up. Although seeking improvements in many areas is not a new phenomenon in professional cycling, it has received increasing attention over the past decade with the success of Team Sky, now INEOS Grenadiers, and team director, Dave Brailsford, who called this concept “marginal gains”. Brailsford and his team set out to win the TdF within five years with a clean British rider (29). To achieve this, he brought with him the approach he used as a performance director for British Cycling, which had led to considerable success in track cycling. Team Sky was established on the back of British dominance in the Laoshan velodrome during the 2008 Beijing Olympics, where they took home seven gold medals. As he transitioned from the track to the road, Brailsford brought the idea that compiling enough marginal gains could provide a greater performance advantage than PEDs (87).

Although the marginal gain concept came to prominence with Team Sky during one of professional cycling’s most recent avowed shift from banned to legal performance-enhancing strategies, it has been practiced by cyclists since at least the mid-1900s. Italian Fausto Coppi, who rode to multiple victories in the TdF and Giro d’Italia, as well as in one-day classics throughout the 40s and early 50s, was an early adopter of novel diet and training approaches. After World War II, the sport of cycling was anything but advanced and Coppi set out to change that. He worked with Bianchi to develop bikes and other equipment; he adapted his diet to better fuel his riding – not only its contents, but also the timing and amount; and he explored strategies for how to best race as a team (37). Some of these developments would later influence other greats, such as Eddie Merckx, who, among other things, was obsessed with proper bike fit (38). Current director of the French national team, Cyrille Guimard, has also long been known for his application of cutting-edge technology and training methods. One of his former riders, Laurent Fignon, described him as being “right up-to-date. He had files for everything. He was interested in all the lates training methods. Where his protégés were concerned, he would look at the very last detail and even the slightest defect would be corrected. He knew how to ensure everyone had the very best equipment that was on the market: made-to-measure bikes, the newest gadgets.” (32, p. 56).

 The notion that modern riders can surpass past performances solely through legal performance strategies rests on the assumption that these strategies, particularly when combined, are highly effective. Furthermore, a larger pool of athletes and an earlier onset of structured athletic development might amplify these effects. The following section explores the degree of improvement that can be made in the areas of training, nutrition, and technology.

There is not a single anthropometric or physiological characteristic that is completely uniform across high-level cyclists (65, 111). Those with elite potential tend to have stand-out absolute measurements of aerobic fitness and power, but these are attributes that can also be found in cyclists of lower caliber. Elite riders also possess very high power-to-weigh ratios, typically expressed as watts per kilogram (W/kg). An emerging concept that may also distinguish riders of different caliber is durability, i.e., the point and degree of physiological decline during extended exercise (66, 79, 80). Laboratory measurements of key performance determinants such as power-to-weigh ratio, V̇O_2max, cycling economy, critical power, and peak power output provide a detailed physiological profile of each individual rider but cannot accurately predict real-life performance.

Training Strategies

Aided by technology, experience, and insights from a growing body of research, training is more refined, structured, and supervised than before, with most, if not all, training sessions serving a specific purpose. Each rider typically follows an individualized training plan that is carried out under comprehensive monitoring of variables such as heart rate, power output, climate, and terrain. These data, along with laboratory measurements, race outcomes, and even psychological variables, are used to adjust volume, frequency, intensity, and/or modality throughout the season. This allows each rider to absorb as much recoverable training volume as possible to optimize physiological adaptations and peak repeatedly for competition while avoiding overtraining. Whereas virtually every single pedal stroke of the modern rider is quantified and analyzed to guide training, racing, and recovery, riders of the past relied more on “feel”, often opting for subjective rather than objective measurements of output. During the 1987 TdF, Laurent Fignon declared his legs to be “functioning again, more or less”, but did not see the value in monitoring his heart rate, explaining that “I lost my temper with those blasted pulse monitors: I handed mine back so that it wouldn’t tell me anything anymore” (32, p. 182).

Although W/kg is often favored as an indicator of riding capacity and a way to quantify cycling performances, a large V̇O_2max has long been considered a basic requirement of entry into the professional peloton. Values reported for GC contenders are generally comparable between generations, with the lowest value found in the most dominant TdF rider of all time, albeit with an asterisk (table 1). There are a few caveats to these numbers, such as the validity of the actual measurement, most of which are not described in the research literature but rather in media. Moreover, oxygen uptake does not increase in proportion to body mass and scaling V̇O_2max to whole body mass is thus not appropriate when comparing athletes of different body sizes (71). Although some of these values may be exacerbated by PED use, both the baseline level and plasticity of V̇O_2max are under considerable genetic influence (15, 86, 135), and WorldTour levels can be reached without doping in those with sufficient genetic predisposition and appropriate stimulus.

Interestingly, there seems to be a physiological trade-off between efficiency and power, where adaptations towards the latter may attenuate the former (72, 113). This phenomenon was observed in Norwegian cyclist, Oskar Svendsen, who once had the highest V̇O2max ever recorded. Svendsen showed promise early by becoming junior time trial champion with less than three years of training and placing high in Tour de l’Avenir. However, despite an incredible V̇O2max of 96.7 ml/kg/min at 18 years of age, Svendsen never became a WorldTour rider. Although his early retirement at age 20 left his potential at the elite level largely unexplored, the reduction in cycling economy he experienced with increased training load could have been resolved as he matured as a rider, as cyclists appear to become more efficient over the span of their careers with little change in V̇O2max (112). If he remained active, Svendsen may eventually have been able to exploit his incredible baseline to reach the proverbial second speed in the modern peloton without chemical assistance. These insights into Svendsen’s physiological profile not only reveal some of the physiological complexities involved in high-level endurance performance, but also serve as an example of the scientific resources available to modern teams and riders that allows for a level of detail in the assessment and follow-up of athletes never seen before at that level of the sport.

Among the many training-related advances in the modern era is a more systematic approach to altitude training. Altitude-mediated erythropoiesis has long been recognized as an exposure that can produce adaptations that improves performance at sea level, as well as acclimatize athletes to sustain performance in hypobaric conditions. There are several ways to approach altitude training and care should be taken to avoid carrying the detrimental effects of prolonged hypoxic exposure, such as reduced cardiac output (Q̇) due to hypovolemia (117), into competition. Today, professional cycling teams rely on both experience as well as past and emerging research to use altitude as an important preparatory measure in various parts of the season. As the individual responses to hypoxic conditions can vary greatly (93), a large hematological response following real or simulated altitude exposure is an important attribute in modern riders. If done properly, altitude training can induce comparable hematological changes to rHuEPO use (table 2), making it a crucial performance-enhancing strategy in the modern peloton. Increasing [Hb] not only improves V̇O2max by improving the oxygen-carrying capacity of blood (43), it also enables sustained work at a higher fraction of maximal capacity (40) and faster V̇O2 kinetics (18), which can be hugely influential in a peloton with limited interindividual difference in V̇O2max.

A more recent strategy to legally induce hematological adaptations is heat acclimation. Prolonged exposure to heat is associated with both increased plasma volume, which can improve stroke volume and consequently Q̇ and V̇O2max, as well as an expansion of total hemoglobin mass (Hbmass) (91). In fact, light exercise in a heated environment five times per week has been shown to increase Hbmass by 3% – 11% in endurance athletes (90, 103, 107). Due to the logistical challenges and cost related to with altitude camp designs such as live high-train low, heat acclimation training may offer a more accessible strategy for riders and teams with less resources, or an additional stimulus to regular stays at altitude.
The mechanistic similarities between synthetic and natural causes of erythropoiesis makes it physiologically possible to harness the benefits of EPO without doping. Voet (132) recounts that pre-scandal Festina riders did not even bring EPO to altitude camps because it was going to be “useless”. Describing his first stay at altitude, formerly enhanced rider, Thomas Dekker, wrote that “[t]he altitude works its magic: the thin air jolts my body into producing extra red blood cells and the Swiss Tour is the first race in ages where I can stay with the pace on the climbs” (25, p. 135), expressing relief that he could hang with the peloton without PEDs. Michele Ferrari, Lance Armstrong’s coach during the height of his career, argues that the effects of EPO on hemoglobin concentration can be achieved through proper altitude training alone (31).

Every rider in the professional peloton possesses rare abilities as cyclists. Given that the sport selects for individuals with above average baseline values of [Hb] and Hct, it may not take much stimulus to maintain a high level. However, compared to simply administering rHuEPO, strategies such as altitude training and heat acclimation are more complex undertakings, partly because of potential drawbacks with that must be accounted for, such as transiently reduced Q̇ and altered dietary requirements. The financial cost associated with prolonged exposure to altitude and/or heat for a professional team is also a considerable barrier, as the finances of teams can differ greatly. In some cases, PED use might simply just be more practical than legal strategies, and not necessarily more powerful.

Improving oxygen delivery and utilization have been main training targets for cyclists throughout most of its history, while resistance training (RT) has been largely neglected. As the impact of both power output and oxygen consumption on cycling performance is intrinsically related to rider weight, maintaining a low body mass has been, and still is, imperative. However, RT with an emphasis on neural adaptations can substantially improve force-generating capacity and reduce the oxygen cost of exercise in athletes without adding unnecessary bulk (51-53, 140). It also helps maintain bone mineral density, which elite cyclists are prone to lose (48, 110). A recent study found that RT with traditional movements and individualized load improved bone mineral density and endurance performance in professional cyclists (126). Moreover, it appeared to improve strength, power, and body composition to a greater degree than short sprint training, a more traditional power training modality for cyclists, supporting the role of structured RT as a part of a professional cyclists overall training program. Indeed, evidence for the benefit of RT on cycling performance has been mounting over the past years (table 3) (62, 102, 104-106, 108, 109, 120, 131, 141). This has contributed to changing the way RT is perceived and applied in the.

An elite physiology is easier to perturb than improve. At the highest level of cycling, large adaptations to training are unlikely to occur in the short term. The full, natural potential of a rider can only be reached via the cumulative effects of proper training and recovery, both of which are highly dependent on proper fueling.
Nutrition, body composition, and supplementation

In Jørgen Leth’s classic documentary, “A Sunday in Hell”, Roger De Vlaeminck can be seen consuming a plate of meat with his team before setting out to defend his multiple Paris–Roubaix victories from the previous years in the 1976 edition, with the narrator explaining that “a rare steak is a good breakfast for what lies ahead” (67). This is in stark contrast to the low-residue diet often consumed by riders in the modern peloton (39). A low-residue diet is characterized by a very low fiber content, which can reduce rider weight and consequently improve race performance (36). This diet is usually combined with a very high carbohydrate intake throughout a race to ensure constant glucose availability, and the reduced satiety that can be associated with low-residue diets may even help a rider maintain energy intake during a race. The exact amount differs between riders, with numbers around 100 g of carbohydrate per hour being a rough estimate that may be exceeded considerably on hard days. The recognition of the added performance benefit of increased carbohydrate intake has given rise to the concept of gut training for athletes (56, 78). Racing hard for hours on end for multiple consecutive days with limited glucose availability is guaranteed to hamper performance compared to a well-fueled athlete; as red blood cells do not convert to adenosine triphosphate; blood doping cannot replace bioenergetic fuel.

There are some examples of riders that leveraged nutrition to increase their performance throughout history, such as Fausto Coppi (37), but in the modern era, all riders pay attention and have access to both nutritionists and chefs, both of which are roles that have become integral parts of professional teams. Riders also have access to more knowledge and tools, such as food apps powered by machine learning (121). The days of training hard during the day following by alcohol consumption in the evening and racing on the weekends are gone, but were reportedly common until fairly recently (25, 54). The culmination of evidence- and experience-based diets in professional cycling has led to better fueling strategies and lower body mass in the peloton and perhaps especially among the best riders.

Although described as “thin as rakes” (132, p. 63), the riders of the 90s were heavy by today’s standard. Laurent Fignon (32) explains that the importance of power-to-weight ratio did not become known among the riders before the mid-80s and that he, until that point, paid little attention to diet. Looking at the top 10 finishers of the TdF for the past four decades, starting with the latest edition, suggest that it is becoming more and more of a requirement for the overall GC placing (table 4). Notably, between 1992 and 2022, the average BMI of the top 10 decreased by 8.1%. This trend seems to generally hold across all Grand Tours for the past decades (118).

Supplements such as creatine and beta-alanine have been shown to improve endurance performance, including in cycling (7, 12, 21, 49, 127, 128). Creatine was introduced to the peloton in the mid-90s but was very expensive at the time. Riders who had access to it could consume up to 30 g the day before a long time trial or a mountain stage in hopes of a performance boost (132). Creatine and beta-alanine are now both affordable and widely used, alongside other supplements such as caffeine, electrolytes, nitrates, various vitamins, and minerals, as well as macronutrient supplements such as protein and carbohydrate.

In recent years, a lot of attention has been devoted to exogenous ketones. It is a contentious supplement that has been embraced some of the strongest teams while being recommended against by the Union Cycliste Internationale (UCI) and the Movement for Credible Cycling (MPCC). Ketones, or ketone bodies, are acetyl-CoA-derived metabolites that are produced by the liver under conditions with reduced glucose availability, such as low-carbohydrate diets, fasting, and during or after hard exercise. Ketone bodies such as β-hydroxybutyrate can spare glycogen by inhibiting glycolysis and acting as an alternative fuel in oxidative phosphorylation, which in turn can improve endurance (19). As with the research on other legal and illegal enhancement strategies, the degree to which exogenous ketones translates to improved exercise performance remains to be fully elucidated (24, 92, 94, 96, 125, 139). Although there may be potential drawbacks with isolated ketone supplementation (82), in conjunction with sodium bicarbonate, which is a weak base that has been used for some time in endurance sports (45), ketone supplementation has been shown to improve power output towards the end of a race simulation by 5% (95), although this effect may be unreliable and warrants further study (97).

Much of the hype surrounding some of the proposed effect of ketones as an energy substrate appears unwarranted, but emerging evidence suggest that it may have intriguing properties as a signaling molecule. A few years ago, it was shown that infusion of ketone bodies increased circulating EPO levels in healthy adults (63). The impact of ketones on EPO is supported by the observation that adherence to a ketogenic diet can increase [Hb] and Hct by ~3%, with the caveat this effect is within the biological variation of these markers (83). Recently, Evans et al. (30) found that ingestion of ketone monoester after cycling exercise increased serum EPO concentration, providing further evidence that it may be the signaling effects rather than nutritional value of ketone supplements confers the greatest performance benefit for professional cyclists.

Technology and equipment
Science tends to be reductionistic by necessity, whereas a cycling race is much more open-ended. There is, however, a certain cycling event that is performed in highly controlled conditions and relies heavily on technological advances that can serves as a good example of marginal gains in modern road cycling: the hour record. In 1972, Eddy Merckx, perhaps the greatest cyclist of all time, rode a distance of 49.431 km to set a new hour record for the first time since the 1950s. Twelve years later, Francesco Moser breached 50 km with an effort totaling 51.151 km, aided by disc wheels and a skin suit. The following years would see various innovative approaches by riders such as Graeme Obree and Chris Boardman, until the UCI decided to revise the rules in 1994 and again in 2014 (table 5). To set his records, Boardman worked closely with Brailsford’s predecessor in British Cycling, Peter Keen, and then later with Brailsford himself after his retirement, on what would be the beginning of British riders’ marginal gains on the track and later in the peloton (14).

From Voigt’s first attempt to Ganna’s latest, the modern hour record has been improved by over 11%. Although Ganna is a multiple World Time Trial champion and likely one of the most suitable riders to attempt the record, the last person to hold the record before him was Daniel Bigham, the only rider on the list that was never a WorldTour rider. Although an accomplished cyclist in his own right, Bigham’s record is a prime example of how far and fast you can get by maximizing the margins, with his record being set at an average power output approximately 100 watts less than Wiggins. Bigham himself puts his performance down to 50% physiology and 50% equipment (137). One of the main aspects Bigham exploited was aerodynamics; his coefficient of aerodynamic drag (CdA) was ~0.15, which is considerably below what is commonly seen in cyclists, including professionals (41).

Aerodynamics is not only relevant when riding fast around a velodrome for an hour, but also one of the most important things to consider when trying to ride fast on a bike in general. At a riding speed of about 54 km/h, close to the average on a flat TdF stage, approximately 90% of the total resistance is aerodynamic resistance (13, 44). Most of the resistance is caused by the rider himself, with common estimates ranging from 60-82% (74), and the rest by other factors such as equipment (22, 73, 77). The importance of minimizing CdA underlies much of the development of modern bike frames, wheels, handlebars, helmets, clothing, and more. In recent years, there has been less emphasis from manufacturers on getting their bikes down to the UCI weight limit of 6.8 kg in favor of more aerodynamic optimizations. This approach is supported by findings showing that simply opting for aerodynamic rather than light wheels will reduce climbing time on 3% – 6% grade hills (57). Steeper hills favor lighter wheels and WorldTour riders often make specific selections of wheelset, gear ratio, and even frameset based on race or stage profile. Some teams take it a step further, such as Jumbo-Visma, who use a portable aero sensor to measure exact wind conditions on race day and make equipment selections accordingly (81).

Since the inception of professional cycling there have been numerous technological advances and there is still a steady flow of innovations reaching the peloton. Some of these become widely adopted, such as aero-optimized gear; some are providing new alternatives without replacing old ones, such as tubeless tires (riders still use a variety of tubed, tubeless, and tubular tires); and others are replacing without immediately improving a function, such as disc brakes. Technology has also enabled more extensive monitoring of athletes, both on and more recently off the bike. For instance, several teams are now measuring body temperature and hydration status, and by analyzing the individual sodium composition sweat, can select the appropriate supplementary amount of sodium for each rider. During very hot days, riders are often seen wearing cooling gear to keep body temperature down. This can not only keep the riders comfortable, but may also benefit their performance in the race by lowering thermal strain (75).

Although professional cycling continues to benefit from science, technology, and engineering, the UCI have rules and regulations in place that ensures that cycling does not, for better or worse, stray too far away from its origins. Although these are subject to change based on new developments, they sometimes can become more restrictive, such as the recent ban on handlebars narrower than 350mm. Riders with the ability and resources to combine effective performance strategies from training, nutrition, recovery, and technology – perhaps especially strategies with small effects that are more likely to be ignored by others – may find themselves able to ride at a different speed than the rest of the peloton.

Merging the margins

Imagine a gifted and durable athlete with an exceptional ability to consume oxygen across all intensity domains, maintain a low body mass, effectively utilize lactate, absorb and recover from a high training load without injury or illness, handle training and race nutrition, thermoregulate in various climates, and respond well to altitude and heat exposure finding his or her way into cycling early in life. Suppose this young cyclist learns to maintain an aerodynamic position on the bike, pedal with an efficient cadence, move seamlessly through the peloton, avoid accidents, calmly handle the pressure of competition, and execute winning moves. Professional cycling selects for individuals with supraphysiological potential from environments that have allowed this potential to be expressed. Then, it awards those who have made it to the starting line and are able make as many performance determinants as possible come together on race day.

Increased professionalism at the highest level of the sport trickles down to the amateur and junior ranks, exposing up-and-coming cyclists to favorable conditions at an earlier age, leading to greater improvements in physiology, psychology, and race craft. Some riders may show incredible promise in some aspects of racing and struggle with others. Oskar Svendsen, V̇O2max world record holder, undoubtedly had one of the greatest physiological potentials ever seen in a rider. However, he admittedly also had technical and tactical challenges: “Cycling is a monotonous sport, yet so complex and driven by tactics that you won’t win races unless you deliver on all those qualities. I came into the sport with good physical qualities, but I struggled most with the tactics and patterns. I did learn a lot in my senior years on Team Joker though, even if I still had a long way to go. Descending down hills was also something I struggled a lot with, and it sapped much of my energy in races.” (99) Svendsen’s career serves as an example of how cycling is not only a physiological sport, but also technical, tactical, and psychological. Recently retired rider, Richie Porte, described former TdF GC winners Chris Froome and Tadej Pogačar as “psychological beasts” and noted that cycling has become increasingly scientific, which does not suit all riders (35). Modern riders are more methodical, data driven, and regimented than before. This reduces the human element of the sport, to the dismay of those claiming that this will increase predictability. Some researchers in the field have also warned against measuring just for the sake of measuring, and advise that rider data should serve a specific purpose (55).

The widely established routine of constant fueling during training and racing not only acutely increase work capacity but also improves subsequent recovery by preventing the rider from becoming completely depleted. This is in stark contrast to the days when reaching for your bottle during a hard training ride, even if it only contained water, was considered a weakness. Paul Köchli, former coach of riders such as Bernard Hinault and Greg Lemond, once said that the art of cycling is to do the right thing at the right moment (27). This is true not only in the context of a race, but indeed for the professional cyclist’s career as a whole. The effects of proper training, nutrition, and recovery accumulate not only throughout a season, but a whole career, benefitting those who consistently do the right things from early on.

Conclusion and future perspectives

In some ways, modern approaches to improving cycling performance represent a first principles approach to cycling and a fundamental challenge of conventions, within the rules and regulations of UCI. It seems to have restored some of the faith in the sport that was once lost with various doping scandals. Given the measurable impacts of legal performance-enhancing strategies, many of which were previously unknown or overlooked, it could be argued that combining these effects can bring a clean rider’s performance close to, or even surpass, that of an enhanced cyclist, assuming a gifted baseline and sufficient degree of adaptability.

Suggesting that it is possible to win at the highest level in cycling without the use of PEDs is not the same as claiming that the sport is completely clean. As others have pointed out, periods that have previously been perceived as clean have later been shown to be anything but (26). This paper covers some of the key legal advances in road cycling that has contributed to elite performances in the modern peloton, while at the same time acknowledging that illegal strategies may still be present.

Much of what was once considered “marginal gains” have now become common in all professional cycling teams. This represents a shift from a culture of doping to a culture of exhaustive continuous improvement, a lot of which is kept under wraps and some that may even be considered a grey area. Effective anti-doping measures contribute to a more level playing field, but not entirely level. The teams with the most resources often get the most talented riders, allowing them to combine the greatest potential with the best strategies. And even still, there are some who favor optimizing riders and their equipment for weight rather than aerodynamics, ignoring the latter to the extent that it becomes a considerable detriment. In an era of professional cycling where individual performances are influenced by a multitude of human and nonhuman factors, which in combination can have profound effects, the existence of two-speed cycling in a clean peloton is not only logical – it should be expected.

Acknowledgments

This work was supported by the Norwegian University of Science and Technology (NTNU). The author would like to thank Dr. Endre T. Nesse and Dr. Fabio G. Laginestra for their comments and feedback on the manuscript.

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