Dispelling myths about distance running

The followers of my blog know that I am a fan of the Act of Manliness newsletter. As I explained, on more than one occasions, the AoM site (and newsletter) is not at all macho. It recognises simply that roughly 50% of us are men and share common interests and preoccupations. But this does not prevent the editors from publishing many articles that can be of equal interest to men and women. It's one of those articles that has inspired this post of mine. 

The content was unashamedly filched from an article by Jason Fitzerald. Jason is a runner, coach and podcaster. He has a 2:39 personal best in the marathon. He runs the Strength Running Podcast and the website Strength Running. His profile highlights that he has "coached thousands of runners to faster finishing times and fewer injuries with his results-oriented coaching philosophy". He points out that running philosophy has changed over the past half-century. At some point, when running became popular (60s?, 70s?) people started running a lot at a slow pace (in contrast to what was the practice up to that point of interval training). However, as running science matured, it became clear that a more balanced approach was necessary, one that includes lifting weights, sprinting, and working on coordination. Instead of slow jogging we have now high-intensity interval training and Tabata workouts. (Just in case you are wondering, the  latter are ultra-short, maximal-effort bursts with 20 seconds of all-out exercise followed by 10 seconds of rest, repeated for 8 rounds to a total of 4 minutes per set. A full session may chain 4 to 5 such sets with one-minute recovery between each set). 

So what are the running-related myths that S. Fitzerald wishes to dispel?

First, running decreases muscle mass. While there is some truth in this (in particular for novices with no aerobic exercise experience) running does not "eat muscle". It simply prevents additional muscle gain. Elite runners are not super-slim because they run a lot: they have the right body type from the outset, one that, combined with training, has allowed them to join the elite.

Second, running requires no skill. This is plain wrong. Training requires coordination and strength. Beginner runners start with a quite un-economical gait, then gradually improve and refine it, adapting it to their morphology, becoming more economical runners.

Third, runners are weak. Fitzgerald insists that it is runners who only run that are truly weak.  A training plan should include more than running with warm-up drills, strength exercises, dynamic stretches and mobility exercises. While aiming at reaching aerobic fitness, a runner should not neglect the structural fitness of tendons and muscles.

Fourth, running increases inflammation and chronic stress. A systemic inflammation can indeed compromise the immune system. However this does not happen unless one over-trains. In fact, effective training should increase inflammation to promote the adaptation response. What one should do is to balance hard training with recovery. 

Five, running doesn’t promote fat loss. This is a major misconception. As shown repeatedly in scientific studies, aerobic exercises, like running, are the most efficient way to burn fat. But, clearly a healthy, balanced diet is critical for fat loss. Running aids in reaching an ideal weight, yet overeating can easily undo those gains.

Running is one of the best forms of exercise available to build fitness. But as Fitzerald points out, both beginners and experienced runners should "stick to a well-rounded training program that embraces variety, plenty of strength exercises, and a holistic approach to distance running".

The transgender question is still not settled

Those who read my blog know that there are certain points on which I am intransigent, and foremost among them is the transgender question. For me, there is no question that men, masquerading as women, should be included in women’s sports categories. I have expressed this view repeatedly in writing on this blog. I have publicly praised Lord Sebastian for his courageous decision to ban transwomen from women’s sports. I rejoiced when the President of the United States signed Executive Order 14201, “Keeping Men Out of Women’s Sports,” to end what I call “transgender insanity”. As I have written time and again, women fought hard to gain access to sports — and we should not let mediocre men spoil the integrity of those sports.

Unfortunately, many people, especially those whom we might call enlightened progressives, are campaigning for the inclusion of men in women’s sports, using the fallacious argument that gender, not sex, should determine eligibility. And there are many misguided women among them! The situation was further aggravated when the IOC, much like Pontius Pilate, chose to wash its hands of the transgender eligibility issue. Before the Paris 2024 Olympics, it abandoned a unified policy and adopted a framework that left such decisions to individual sports federations. As a result, two biologically male athletes were allowed to compete in women’s boxing.

It is important to note that the regulatory landscape of boxing was particularly complex at that time. One year before the Games, the sport was still under the authority of the International Boxing Association (IBA). However, after governance failures led to its suspension in 2019, the IOC formally decertified the IBA in June 2023 and took over the organization of Olympic qualifiers and the event itself. Although the IBA had previously disqualified Imane Khelif and Lin Yu-ting over eligibility concerns, the IOC permitted both to compete in Paris—with predictable controversy following. Since 2025, the IOC has recognized the newly established World Boxing federation as the sport’s international governing body. One of the first measures of WB was the announcement of systematic testing for the SRY gene as part of eligibility screening. Still, Khelif who, in a February 2026 article in l'Equipe, confirmed that she has the SRY gene, is planning to participate in the 2028, Los Angeles, Olympics. But since the WR is screening for the gene, Khelif will not even be allowed to take part in the qualifiers. Imane Khelif is not transgender: she is male. (I find the last sentence somewhat bizarre, but since Khelif has a female phenotype and maintains that she is a woman I will, as a courtesy, use the female pronoun). 

I do not know whether the IOC, after the outcry following the Paris boxing scandal and profiting from the change of presidency will change their cowardly stance. To tell the truth, I am not overly optimistic, but I am willing to give them the benefit of the doubt.

The main reason I am revisiting the transgender question is that there are regularly published supposedly scientific papers advocating for the inclusion of transgender men in women’s sports. The IOC’s 2021 Framework on Fairness, Inclusion and Non‑Discrimination already adopts a “no presumption of advantage” principle, rejecting blanket testosterone thresholds for transgender athletes. These assumptions tend to downplay the lasting effects of male puberty on strength, muscle mass, and overall physiology. Testosterone suppression does reduce muscle mass and strength and brings hemoglobin levels into the female range. However, the biomechanical and performance advantages acquired during male puberty are not fully eliminated. Despite this, the IOC chose to prioritize inclusion, effectively allowing biologically male athletes to compete against women. This time, a new publication brought to my attention in Ross Tucker’s podcast prompted me to write on the topic again. (If you follow my blog, you will already know who Ross Tucker is).

The paper in question was published in the British Journal of Sports Medicine under the title “Body composition and physical fitness in transgender versus cisgender individuals: a systematic review with meta‑analysis”. What was flabbergasting was their conclusion:

While transgender women exhibited higher lean mass [my addition: which is a proxy for muscle] than cisgender women, their physical fitness was comparable. Current evidence ...[omitted]... does not support theories of inherent athletic advantages for transgender women over cisgender.

It is one of those dubious studies, on transgender individuals, published in the last three or four years, that have been co‑opted into debates about elite sport. Ross Tucker thoroughly dismantles it: the article takes weak primary studies, applies technically sound statistics for credibility, and produces an outcome that, in practice, means very little. Yet this does not stop the authors from claiming that “the current data do not justify blanket bans”. The problem lies in the studies used as the basis for this meta‑analysis. A typical pitfall is to compare men who identify as women to elite women athletes. But this is not the correct way to conduct the comparison. In a marathon, the top 30 men are about 10–12% faster than the top 30 women. However, when one moves further back in the field, there are many men who are slower and weaker than many women. In a local race, perhaps 30%, or even 50%, of the men are beaten by the first woman. The best women are excellent athletes in the human race. The same logic applies to age categories. The best junior sprinter is often faster than most adult men. Does this mean that being young is not a disadvantage? Should we then allow adult athletes to compete in junior categories on the grounds that they “feel young”? 

Tucker insists that if we are to require studies to be robust and have good scientific integrity, one of the prerequisites is that they consider comparable slices of the male and female populations. Overlooking this, the conclusion can easily be that males are similar to females. He finishes by expressing the hope that the next time we speak about transgender athletes, it will be to report that the IOC has finally aligned its policies with the reality of biology and sport. Amen to this.

Vaporflys or how supershoes changed the Marathon forever

Those who follow my blog have noticed that I have a great esteem for Ross Tucker, a renowned sports physiologist. Together with his colleague Jonathan Dugas, Tucker had a blog entitled "The Science of Sport". It was active from 2007 to 2013 and then went silent. The last post in the blog was on the sub-2 hour marathon. And the title expressed clearly the authors reservations: "Is the sub-2 hour marathon imminent? Don't hold your breath". Well, it turned out that they were somewhat pessimistic or rather they didn't predict the revolution that would take hold of long distance running in the years to come. And six years after the Science of Sport article, Eliud Kipchoge ran the first sub-2 marathon in history.

In 2013 the men's marathon world record was held by W. Kipsang with 2:03.23. The women's records were established back in 2003 (mixed race) and 2005 (women only) by P. Radcliffe with 2:15:15 and 2:17:42. Today the men's record is held by the late K. Kiptum with 2:00:35 and the women's records are held by R. Chepngetich (mixed race) with 2:09:56 and P. Jepchirchir (women only) with 2:16:16. Just to put the women's records in the right perspective, the men's 2:10 barrier was broken in 1967 by D. Clayton. (At that time no woman had run under 3 hours). And what is happening it's not only due to some exceptional individuals. We are witnessing a real revolution in long distance running. One can argue that what we observe is due to better training and a ripple effect where the performance of the leaders reverberates through the whole runner community. Maybe so. But there is one factor that has undeniably contributed to the explosion of performances: shoes.

But let us start at the beginning. At the end of the 90s the team of the Human Performance Laboratory of the University of Calgary started interesting themselves in the effect of shoe bending stiffness on jump height performance. In order to increase the stiffness they inserted a carbon fibre plate into the shoe midsole.

The initial studies were targeting high jump but subsequent studies extended the subject to that of running economy. It was well known at the time that the energy put in on the metatarsophalangeal joint (the joint between the metatarsals and he toes) is not returned when pushing off. Using shoes with inserted carbon plates reduces the energy dissipated in these joints. The Calgary research showed running energy savings of approximately 1% when using a stiff midsole as compared to a "normal" one. To put the result in perspective (since the energy expenditure for running is proportional to the athlete's velocity) a 1% gain would mean shaving off more than a minute from the time of a marathon for an elite runner.

Curiously the Calgary study did not have any impact on the shoe industry for more than a decade. It was around 2015, when people from the Calgary lab went to work at Nike, that the new shoe generation saw the light. The first modification with respect to the initial design was a bent plate. The reason is that a flat plate makes it actually harder for the calves to push up. The team of the Locomotion Lab at the University of Colorado studied the prototype of the shoes that would become known as the Vaporflys and found that they lowered the energetic cost of running by 4%.

Kipchoge did attempt an under-2 marathon using Vaporflys in 2016 in the Breaking2 event held in Monza. He came tantalisingly close to the 2-hour barrier, completing his run in 2:00:25. While the course design was legitimate (flat course) the remaining conditions (like the use of rotating pacemakers shielding the star runner and the use of a car projecting a laser beam to aid pacing) made that the record could not be homologated. 

While the people of the Calgary lab attribute the energy gain to the stiff plate, the Colorado team's opinion is more reserved. For them the metabolic savings of the shoes appear to be due to a superior energy storage in the midsole foam, the clever lever effects of the carbon-fibre plate on the ankle joint mechanics, and the stiffening effects of the plate on the metatarsophalangeal joint. Apparently the midsole foam plays an important role. When the foot hits the ground the sole deforms and some energy is lost. However in today's "supershoes" better foams result in diminished energy loss. (And Nike did further improve upon this by introducing air-filled rubber cushioning).

Following these studies Nike came up with a better model, the Alphafly. Kipchoge used them in Vienna in 2019 at the Ineos 1:59 Challenge and this time the 2-hour barrier did fall. Today Alphaflys are available to anybody who can afford the rather stiff price. 

The other brands have caught up with Nike and this explains the explosion of records. World Athletics are trying to put some order in this. They require that shoes be on the market for a month before they can be used in an official competition. Moreover there are limiting the stacking height (the amount of material between the foot and the ground) for track events to 20 mm. However the marathon shoes are allowed to have a 40 mm stack height. Some people are speaking about "shoe doping". I believe that this choice of words is most unfortunate since nobody is cheating and everybody has access to the new shoes. But it remains that they give the athletes a massive advantage. 

If you wish to learn more on supershoes, I suggest that you read an excellent article on Runners World.

Speaking of the advantage offered by the shoes reminds me of a controversy going back to the 50s. In 1957 Yuri Stepanov, a soviet high jumper, broke the World Record with a 2.16 m jump. When photos of the record attempt were circulated people noticed that Stepanov was wearing a shoe with a thick sole on his take-off leg. 

People cried foul (some were talking about a 4 cm "trampoline" but a closer examination of the photo, as well as other photos of Stepanov in competition, point at a thickness not exceeding 2 cm). In absence of specific rules the IAAF homologated the record and proceeded to limit the shoe sole thickness to 13 mm. This limit has been raised today to 20 mm. (But as P.J. Vazel is pointing out, it is not clear that an elevated shoe offers any advantage in the Fosbury style, it might even present some risk due to the quite different take-off technique). While Stepanov's sole thickness would have been acceptable with today's rules, back in 1957 he was heavily criticised by the media. Being mentally fragile he foundered into depression, alcoholism and committed suicide in 1963, at just 31 years of age.

PS And when we thought we had seen everything, along came the running sandals. 

B. Kiplimo won a Marathon in Thailand running with carbon-plated sandals. Now, how can anybody run 42 km with this kind of shoes is a mystery to me. But Kiplimo did it and won the race in a respectable 2:18:55 time.