Photo by Pasja100 (Pixabay)

The pacing strategy alternating periods of walking and running is known as the Galloway Method, after Jeff Galloway, the former US Olympic runner who popularized it. According to his theory, walk breaks help to endure fatigue and reduce or eliminate muscle breakdown.

Worth to mention that this run-walk method is not used only when the athlete is tired, but throughout the whole race. By reducing overall impact on the body, it has allowed many runners, especially beginners, to go farther, and even faster, than they would have achieved simply by running.

According to the runner level and strategy the running:walking intervals may differ greatly, going from an easier 1:1 ratio to a more demanding 8:1, when the runner would run 8 continuous minutes and then walk during 1.

Despite the Galloway Method popularity, a question remains:

Does a runner need more energy when changing speeds or while running at a constant pace?


The study

A recent study has used a treadmill and a group of recreational runners who did the following:

  • 6 min continuous running
  • 6 min continuous walking
  • 12 min alternating 2-min periods of run and walk

Being measured the energy expenditure per kilometre (kcal/km), the distance traversed per litre of absolute oxygen (m/L O2) and the rate of perceived exertion (RPE) for each of the conditions.



  • Energy expenditure

Walking consumed less energy (9 kcal) for a given distance than running, although when alternating every two minutes participants required 4 kcal extra to traverse one kilometre than running it. For a marathon race it would mean 168 kcal more.

  • Distance traversed

Walking allowed participants to traverse 12.31 metres farther per litre of oxygen consumed than while running. There was no difference when between participants running or using the Galloway method.

  • Fatigue

There was only a small reduction in perceived exertion for the runners when using the run-walk method than with continuous running.


  • Alternating periods of running and walking did not save any energy per kilometre when compared to continuous running and only offered a slight reduction of perceived fatigue.
  • On the positive side, the Galloway method can reduce the risks of injury and allow a better management of fatigue, pain, and discomfort in marathons, although limiting the performance.



Run-walk marathon pacing: the energy cost of frequent walk breaks. William P. Nolan & Andrew R. Moore (2021), International Journal of Performance Analysis in Sport, 21:1, 170-179, DOI: 10.1080/24748668.2020.1862493

Photo by Drew Farwel (Unsplash)

ESGUEVA MARATHON (23/04/2021 – 96)

Picking up the torch from Quique´s marathon two weeks ago, it is time to organize a new one. The chosen date, Friday April 23, festivity of Castilla y Léon, and incidentally commemorating the fifth centenary of the “Comuneros” defeat in the Battle of Villalar.

The circuit will follow the riverbank of the Esgueva as it leaves Valladolid, a linear and flat route of just over 7 kilometres that will have to be run 6 times to complete the distance of Pheidippides.

At the start, once again the usual ones: Quique, Lola and David, both going for their fourth marathon on as many weekends, and Kacho opting for half the distance. Pepe is going to miss it.

Being festive only at regional level does not help travel, but with four for the marathon, we are enough to “validate” it, a criterion that will still give a lot to talk about.

During the week forecast had been promising water, although later it changed, and finally the morning appears only with some clouds and good temperature.

After two weeks of active rest, trying to recover physically (and psychologically) from the last event, it seems that things can go better today. Thus, and although not perfect of “sensations”, at least I can manage to run the first 2 laps with the others.

Shortly afterwards David pulls forward and we let him go. I still make it to the half marathon with Quique, who has been holding back so as not to get me off the hook. By that point I still have a small margin to get below 4 hours.

Later in the day we must overcome quite a few walkers and cyclists, something that I did not have foreseen, as I usually have trained on this path much earlier and during weekdays.

Meanwhile, the race continues its course. I keep Quique and Lola at a visual distance, while David is already quite far. Running back for the last time and seeing that the 4 hours are going to escape me again, I squeeze what is left in me.

In the end I cross the finish line at 4.04.28, improving almost 20 minutes the debacle of 13 days ago, although again above the 4 hours finish time. On the positive side, a marathon less to reach the 100-barrier…

After the fifth MIV marathon, during the post-race talk, we begin to glimpse the light at the end of the tunnel for the “official” competitions. Among others, the names of the marathons of Gran Canaria, San Sebastián, Reykjavik, Tokyo and even the North Pole ring out …

It is what the marathon has that, like sports in general, knows no borders, and will survive to Covid, even if it is based on PCRs or “clandestine” marathons.


Photo by Massimo Sartirana (Pixabay)

According to the American College of Sports Medicine up to 50% of athletes use nutritional supplements. Among the most popular supplements nowadays are antioxidants, used to improve performance and fight against Exercise-Induced Muscle Damage (EIMD) and fatigue.

Two of the most popular antioxidants are vitamin C and vitamin E, capable of neutralising the reactive oxygen species (ROS) derived from intense exercise. Despite their extensive use most athletes consume adequate levels daily (Vitamin C: 75 mg/day females – 90 mg/day males; Vitamin E: 15 mg/day) in the diet through fruits, vegetables, and nuts, among other sources.

Some authors suggest that the transient rise of ROS with exercise is beneficial. Thus, antioxidant supplementation could impair athletes training adaptations, instead of helping them.

A recent review has investigated the effects of vitamin E and C supplementation on exercise performance. Their main findings are described below.

Vitamin C

  • Muscle strength and function are not affected.
  • Individuals with vitamin C deficiency increase exercise performance with supplementation.

Vitamin E

  • Effects on endurance are confuse.
  • During high intensity intervals acute supplementation improves performance (less oxidative stress and faster recovery).
  • Chronic supplementation may impair training adaptations and future exercise performance.


  • Chronic supplementation with vitamin E (with or without vitamin C) impairs athletic performance and is not currently recommended for athletes (except for those training at high altitude).
  • Acute antioxidant supplementation improves performance in high intensity/short recovery intervals exercise, conditions where an IMMEDIATE enhancement of performance is pursued.
  • To ensure antioxidants needs athletes should focus on consuming a diet high in them (fruits, vegetables, nuts…) instead of using supplements.
  • Determining the oxidative state of athletes would allow personalized supplementation.



Antioxidants and Exercise Performance: With a Focus on Vitamin E and C Supplementation. Higgins MR, Izadi A, Kaviani M. Int J Environ Res Public Health. 2020 Nov 15; 17(22):8452. doi: 10.3390/ijerph17228452.

Antioxidants rich foods


Staring group (lacking Pepe)

We returned to the distance of 42 kilometers in the vicinity of Valladolid. Quique organized in the pine forest of his village, Tudela de Duero, the next “clandestine” marathon of the Independent Marathons of Valladolid MIV.

Given the circumstances, we are 6 runners for the marathon, and 3 for the half-marathon distance. Among the marathoners, familiar faces such as Pepe, Quique and I from the locals, Lola and David from the Madrid side, and Joserra from Galicia as a new addition.

The morning dawned with good temperature, although with a forecast of rain, to do 14 laps of a circuit through the pine forest around the Santinos recreational area.

The last two weeks had been the chronicle of an announced failure. No day had I ever found myself fresh. I don’t know if the February and March “loads” were excessive, or the recovery time was insufficient.

I started running calm and lagged the leading group a bit. There are many laps and I have them in sight. I can close the gap whenever I want (I think).

Santinos pine forest

However, already in the second lap I feel that the legs do not accompany, and the feeling will only get worse as the race goes on. At the end of the fifth lap it starts to rain heavily, and some puddles appear on the sandy ground, but without causing much discomfort.

In the middle of the race, and with another 7 laps to go, the mind has a lot of work to do. The ghost of a DNF flies over my head, although the pleasant journey through the pine forest makes up for the effort.

The distance of Pheidippides always commands respect, and sometimes demands a toll, bringing out the best in us. You must forget the stopwatch and focus on finishing. I still remember marathons like the Lemmings track or the one in Funchal, and they are not enjoyed the same… It is feeling your body dissociated: going well at core level, but the legs not responding.

Running the penultimate lap, Quique and Lola get to double me. But my marathon is another one, and already within reach…

I cross the finish line with 4.23.57, a time that leaves me unsatisfied, although it serves to add the 95 to my personal count.

We will return, hopefully with better feelings.

Some time into the race (before the rain)


Photo by Quino AI (Unsplash)

During the 1990s some studies calculated that women would overtake men performance in the marathon event, because of their steeper increase in running velocity over the years.

Despite these studies, other models defended that there would always prevail a 10% difference advantage of males over females in running performance, due to their greater aerobic capacity (VO2max). This was confirmed by studying more than 90000 non-elite marathoners, where males had finishing times around 10% faster than females (4h28m vs. 4h54m).

But let´s talk about ultra-endurance sports, whose popularity has increased a lot in recent years. In these events, success is determined by a whole set of factors. We could highlight oxidative capacity, running energy cost, fatigue and pain resistance, nutrition, gastrointestinal system, experience, strategy, and motivation, among a few others.

Any runner needs a good set of skills to compete successfully in an ultra-marathon, but also be able to endure high training volumes and push their physiological limits to the edge.

On the marathon distance male/female ratios are around 50%, with males running a 10% faster than females, as we have mentioned previously. In ultra-endurance events though, female participants are often in higher numbers than males.

In these long events, the difference in finishing times between males and females goes down to 4% in ultra-marathons, 6% in ultra-distance open water swimming and is absent in cycling events longer than 200 miles.

Do these numbers mean that females are more physiologically prepared to endure the hardest of the events? Or these lower differences may be due to greater participation and training opportunities nowadays?

A recent article has reviewed the factors that could explain this potential advantage.

Photo by Quino AI (Unsplash)


Fibres in human skeletal muscles can be type-I/slow or type-II/fast.

Type-I fibres are more resistant to fatigue, accounting in a study for 44% of the total fibres in females and only 36% in males. Additionally, they are associated with higher levels of capillarization and blood flow to the muscles.

Regarding muscle mass, males are more muscular, due to a greater diameter of the muscle fibres and not because of a higher number of them. Stronger muscles can restrict blood flow and lead to muscle fatigue earlier during isometric submaximal exercise.

Both factors would favour females having a greater resistance to fatigue than males.

Regarding the respiratory muscles, though, it seems that females are in disadvantage. Due to lung size, diameter of airways and the utilization of a greater percentage of VO2 during effort they could have lower oxygen economy during exercise.


Substrate utilization

Oxidative metabolism is essential in ultra-endurance exercise. The longer the distance the more intense is the use of free fatty acids.

Females show greater expression of genes associated with the metabolism of fatty acids, as it is the CD36, associated with a 4-fold increase of fatty acids metabolism in a mice model.

Thus, females could have a metabolic advantage during long duration exercise. Better efficiency would reduce caloric requirements and the need of exogenous carbohydrates.


Oxygen use

Aerobic metabolism is limited by the maximal oxygen uptake. Superior performance in males is associated with higher VO2max values, trained or untrained.

Although the lower VO2max would certainly be a disadvantage for females in races of any distance up to the marathon, there are other factors influencing the performance in ultra-marathon events.

Thus, females have usually more conservative running strategies, explaining why they often are capable to maintain pace better than males. They take decisions to mitigate muscle damage and fatigue, key limiting factors of performance.


Gastrointestinal disorders

The most common disturbances in sports are nausea/vomiting and abdominal cramps, with a higher prevalence in females.

Despite this, due to better substrate efficiency, lower body mass and lower caloric needs females don´t need to consume as many carbohydrates as males. This is of special relevance because carbohydrates intake is the main cause of gastrointestinal disorders.

Thus, although female athletes may be more prone to gastrointestinal disorders, their lower caloric needs may compensate for these disturbances.



  • Female athletes exhibit various characteristics that can confer them an advantage in ultra-endurance sports: a greater percentage of type-I fibres, greater fatigue-resistance, better substrate efficiency, lower energetic requirements and even be better at pacing.
  • But some physiological characteristics can counteract these advantages, such O2 carrying capacity, gastrointestinal disorders and hormonal effects on cellular function and injury risk.
  • Considering the pros and cons of the factors mentioned above, the current article concludes that the fastest females will never outperform the fastest males, except in ultra-distance swimming.



Do Sex Differences in Physiology Confer a Female Advantage in Ultra-Endurance Sport? Tiller, N.B., Elliott-Sale, K.J., Knechtle, B. et al. Sports Med (2021).

Photo by Jasmin Sessler


Mizuki Noguchi winning the 2004 Olympic marathon

“I want to keep running until my legs break down for good.”

Mizuki Noguchi

The 2004 Summer Olympics saw the Olympic Games go back where they began. Athens was chosen as the host city leading all the voting rounds, defeating Rome, Cape Town, Stockholm, and Buenos Aires. That would be the second time that Athens would hold the Olympics after the inaugural ones of modern times in 1896.

Regarding the marathon, it would follow the same route than the 1896 Olympics. Starting on the site of the Battle of Marathon it would finish in the Panathenaic Stadium of Athens. And it wasn´t an easy course, with many hills until the final ten kilometres, that were mainly downhill.

The women´s marathon was going to take place on August 22 at 18.00. Considering Greek´s summer weather it was going to be a tough race. For starters the evening offered a 30% humidity and 35°C!

Let´s see first how the women´s marathon scene was at that time…

The main favourite was the British Paula Radcliffe, who had dominated the marathon distance since her debut in London 2002 with 2.18.55, the second fastest time ever. Later that year she won Chicago with a WR of 2.17.47, a time she further improved in London 2003 to 2.15.25. But 2004 had been a tough year for her, with various injuries complicating her training schedule.

Besides Radcliffe, the Kenyan Catherine Ndereba was second in the rankings and World Champion. And here was, as usual, a powerful Japanese team with Mizuki Noguchi and  Naoko Sakamoto, who had been second and fourth in the World Championships of Saint-Denis in 2003, and the strong Romanian Lidia Simon, already silver in Sydney 2000.

Noguchi started running short distances in school, before transitioning to cross-country events, where she won the gold medal in the Asian Championships of 1999. That same year she won the Inuyama half marathon, and focused on this event, where she would manage to win 14 out of 24 half-marathons. She tried for the first time the full marathon distance in 2002 in Nagoya, where she won in 2.25.35. The following year she won the Osaka women only marathon in 2.21.18, finishing second in the World Championships (2.24.14).

But it is time to get back to the 2004 Olympics marathon, where 82 runners were starting the race.

Radcliffe took the lead of the race from the start, with a group of runners tagging along. They crossed the 10k in 34.25 and the 20k in 1.09.57. None of them were playing their cards, but everything was about to change.

Passing the 25k there was an uphill section, where Radcliffe struggled to keep her pace. That seemed as an opportunity to Noguchi, who increased her pace and took the lead. Crossing the 30k (1.45.02) she was leading 28s ahead of Elfenesh Alemu, from Ethiopia. Shortly behind them were coming Radcliffe and Ndereba.

Near the 35k Radcliffe launched a desperate attack searching for the medals. It was futile. Overtaken by Ndereba, and temporarily out of the medal positions, she stopped on the side of the road. Sobbing, and lost all hope, she abandoned the race.

Meanwhile Ndereba was closing the gap with Noguchi. In the 40k (2.19.00) her lead was down to just 12s. The next two runners were much further: Alemu at 1.17 and the United States’ athlete Deena Kastor, at 1.35, strongly chasing the bronze medal.

Entering the Panathinaiko Stadium Noguchi kept her lead, winning Ndereba by 12s and a second consecutive gold medal for Japan in the event with 2.26.20. The bronze medal went surprisingly to Kastor in 2.27.20, who had run the second half of the race 4 minutes faster than the first!

From the 82 starters, only 66 finished the race.

Noguchi´s victories weren´t over. She won the Berlin Marathon of 2005 with 2.19.12, establishing the course record, but also the Japanese and Asian ones. She didn´t go to the Olympics of Beijing 2008 due to physical problems and missed also the following two seasons. In 2012 she failed to qualify for London 2012. A talented runner she run many other races in a range of distances before retiring in 2016.

Regarding Ndereba, she would add another two Boston Marathon victories to her previous two ones and would have another shot to Olympic glory in Beijing 2008, similarly to Kastor, but…

It will be told in a future post.

Thanks for reading!



Athens 2004 Olympics opening ceremony


Photo by Jane Sundried (Unsplash)

The therapy

HBOT is medical treatment that involves breathing pure oxygen in a pressurized chamber (ambient pressure higher than atmospheric pressure).


A brief story

  • 1662: British physician Nathaniel Henshaw builds a pressurized room to treat pulmonary and digestive conditions.
  • 1788: hyperbaric air in a diving bell is used for underwater repairs.
  • 1819: first deep-sea diving suit.
  • 1834: French doctor Junod builds the first hyperbaric tank to treat a variety of medical conditions.
  • 1900s: Frech doctors discover that patients with surgery in hyperbaric conditions recovered with fewer complictations.
  • 1907: JS Haldane designs decompression chamber to treat decompression sickness in divers.
  • 1918: Dr. Orville Cunningham discovers a difference in flu´s mortality rate among patients living at high altitude, leading to many patients to seek HBOT treatments.
  • 1963: JFK´s child, Patrick Bouvier, is treated from Respiratory Distress Syndrome in a HBOT chamber, although he dies aged 2 days.
Individual hyperbaric chamber

How does it work?

  • On wound healing: damaged blood vessels release fluids that cause swelling in the tissues, depriving them of oxygen. HBOT helps healing by providing tissues with plasma rich in oxygen. Additionally, it helps to remove the harmful free radicals.
  • On immune system: HBOT improves the ability of white blood cells to fight against infectious diseases and foreign invaders. It also blocks the action of many harmful bacteria.
  • On aging: telomeres are the end parts of the chromosomes and their shortening is linked to aging. Elongating theses telomeres is associated with a longer life, and although exercise and a healthy diet have been shown to have small effects on them, HBOT is said to reverse aging. Patients that received oxygen therapy sessions daily over 3 months showed longer telomeres and a smaller number of senescent cells than control individuals.
  • On sports recovery: HBOT induces the formation of new collagen fibres, present in muscles, tendons, ligaments, cartilage, or skin, among others.


The chambers for HBOT can be monoplace, where the patient slips into the chamber, or multiplace, designed as a room where various persons simultaneously breath through masks.

Sessions, lasting up to 2 hours, should be provided only in healthcare or approved facilities, and is not recommended in people with ear problems, cold, fever or some lung diseases.

Although an expensive therapy, its use is becoming more common. Among the famous sportsmen using HBOT therapy we can find Rafael Nadal, Cristiano Ronaldo or Lebron James. But does HBOT also improve performance? Its effects are unclear yet.

Did you have any experience with hyperbaric oxygen therapy? We would like to read your comments.



John Scott Haldane: The father of oxygen therapy. Sekhar KC, Rao SC. Indian J Anaesth 2014; 58:350-2.

Multiplace hyperbaric chamber


It was clear from how things were going that the easiest way to run a marathon was to organize one. After overcoming in December the fear of doing something for the first time, it seemed the ideal moment for another marathon from the runner/organizer perspective.

Taking advantage of a gap in the calendar, since the Madrid Command is going with everything, we opted to concentrate efforts on a single day, Sunday, March 7. And again the chosen site was Zaratán, but instead of the last route, opting for a friendlier one: the Vía Verde of the Tren Burra (Donkey Train). Like the missed Vías Verdes marathons, we would use a reconditioned old railway, in this case the one that made the Valladolid-Medina de Rioseco route until 1969.

On a 6.55 kilometres course, 1 short lap and 6 full laps would be necessary to complete the marathon distance. Of course, once again to show that Valladolid is not as flat as it seems, it was a demanding marathon, with a smoothly ascent in the way out, but difficult after repeating it several times.

In the end we were only 5 runners at the start: Pepe, Quique, Lola, David and me, who have already shared a few marathons. With a punctual start at 9.00 it is a perfect day to race, improving the weather forecast. It was just a matter of completing the race in the best possible time, especially not knowing when we will be able to have another chance to run a marathon.

Although during the first 2 laps we ran close to each other, we end up running alone, except for Quique and Lola, who escape in front, although I manage to keep them in sight. Facing the last lap I am counting on maybe reaching them. However they are strong and I have no chance.

I enter slightly above the 4-hours barrier, at 4.03.19, thus completing the marathon number 94, first of 2021 and first on a day 7.

All gathered at the finish line, new marathons begin to be shuffled: that is one of the dangers of the marathon family. But the most important bit is that everyone has a place in it, from the lone wolves to the marathon hunters.

Meanwhile we will continue looking for courses and experiences.


“I had never run just to participate; I always ran for victory.”

Gezahegne Abera

After the women´s marathon, which finished with victory for the Japanese Naoko Takahashi, next in line was the men´s marathon, scheduled for the last day of the 2000 Sydney´s Olympics, October 1st at 16.00.

Never so many runners had been at the start: 100 athletes from 65 different countries! And the battle ahead didn´t look easy. Six of the top eight participants from Atlanta 1996 were there, among them the three medallists: Josia Thugwane (South Africa), Lee Bong-Ju (South Korea) and Eric Wainaina (Kenya). And there was also the reigning world champion, Abel Antón, from Spain.

Gezahegne Abera was born in Etya, in the Arsi province of Ethiopia, the same region than famous Haile Gebrselassie and many other Ethiopian champions. As a child, he had to run 25k every day to go to school while also working in his family´s farm, and all this at 2500 metres of altitude! He first competed in cross-country, where he was noticed and offered a place in the national junior track squad, moving to Addis.

In 1998 he debuted in the marathon, finishing 3rd in the first Abebe Bikila Memorial Marathon in Addis. Thanks to this result he was selected for the 1999 Los Angeles Marathon, where he finished 4th (2.13.59), qualifying for the World Championships in Seville. There he only finished 11th (2.16.42), but later that same year he won in Fukuoka with a great time of 2.07.54. Already in 2000, he finished second in the Boston Marathon, arriving to Sydney as one of the youngest and most promising competitors.

Once the Olympic marathon started Tiyapo Maso from Bostwana took the lead, and he was going to be there for a long time. He crossed the 10k in 29.58, and the 20k mark in 1.00.46. It was a windy day, and many of the runners were saving energy tucked into packs.

Maso´s strategy proved wrong, and shortly after the 24 kilometres he was surpassed by a group of four runners that soon turned into three, Ethiopian Abera accompanied by his team mate Tesfaye Tola, with Wainaina from Kenya, who was eager to improve his third position in Atlanta 1996.

Wainaina knew that the Ethiopians had much in their advantage working as a team, so he tried his luck several times. Nearing the finish of the race his effort paid him off, as he was able to leave Tola behind after the 40k, but soon after Abera surpassed him, taking an unsurmountable lead as he entered alone into the Olympic Stadium.

Thus, Abera won the Olympic gold medal in 2.10.11, getting the 4th Ethiopian victory in the event, following a long tradition that had started with Abebe Bikila in Rome 1960. But he also became the youngest Olympic champion in marathon.

Finally, Wainaina got the silver medal with 2.10.31, improving his bronze from Atlanta 1996, although victory escaped him once again. The bronze would be for Tola (2.11.10), showing the rising dominance of African nations in the marathon distance at international level.

We could highlight the 6th position of the Spanish Martin FIz, who had been 4th in Atlanta 1996. It was the last chance of Olympic glory for him and a whole set of European athletes from his generation, among them his teammate Abel Anton (Spain and World Champion twice), and Portuguese runners Antonio Pinto and Domingos Castro. A new wave of African runners had arrived, and they were here for the long haul.

Our winner Gezahegne Abera became world champion in 2001 achieving for the first time an Olympics-World Championships marathon double. He won again in Fukuoka in 2001 and 2002, and also the 2003 London Marathon. Soon after injuries plagued him and although he qualified for the 2004 Olympics in Athens, he didn’t compete. His wife Elfenesh Alemu, also a marathoner, finished fourth in the women’s marathon in Athens 2004.

Regarding the other two medallist, Wainaina would try his luck for a third time in Athens 2004, where he finished in a meritorious 7th place, while Tola had a long marathon running career, that spanned until 2013, whose best result was in the World Championships of Edmonton 2001, where he finished in 4th position.

And we finish here our visit to the marathon in Sydney 2000.

Our next entrance of the series will be focused on Athens 2004, and the victories of Mizuki Noguchi (Japan) in women and Stefano Baldini (Italy) in men.



Sydney 2000 Olympics closing ceremony


Photo by MIguel A Amutio (Unsplash)

Since the introduction of the first carbon fibre plate (CFP) shoes by Nike in 2016 we have seen most of the long-distance running world records (WR) beaten. Another recent example would be the 42 runners that broke the 2h 10 minutes barrier in the Lake Biwa Marathon in Japan.

World Athletics (WA) ruled in 2020 that sole thickness should be lower than 40 mm (or 25 mm for spiked shoes), has a maximum of one rigid carbon plate and be on sale for at least 4 months before competition.  Later, an amendment was approved allowing prototype shoes to be worn in international competitions upon approval of the shoe specifications by WA.

A new article has tried to answer the following questions:

  • Have these sudden improvements in performance been physiological, or only a consequence of shoe technology?
  • Would WA regulations be enough to keep the competition fairness?


Key points

CFP shoes offer savings of up to 4% in running economy that can lead to 2% faster times in running events. This performance improvement would be similar to that expected from various doping agents prohibited by the World-Anti Doping Agency (WADA), such as EPO.

But attention should also be given to potential injuries. A higher risk of injury could be linked to a lack of foot stability. Don´t forget that these shoes require some time for adaptation, and that Kenenisa Bekele claimed that this instability injured him before his 2020 London Marathon.

Similar situations with technological advances have happened previously. In 2009 the International Swimming Federation had to modify its rules and ban the full-body swimsuits after a series of WR were broken in a very short period of time.

But there examples also in athletics. In 1968 consecutive WR in the 200 and 400 metres using 68-spikes shoes lead the IAAF to ban this technology. So many spikes allowed for a better grip and stability on the racetrack.



  • New rules from World Athletics seem inadequate: shoe technology should not be the primary determinant of sporting performance.
  • A potential solution should be to limit the stack shoe height to 20 mm, instead of the current 40 mm, thus limiting the role of shoes on running performance.



Recent Improvements in Marathon Run Times Are Likely Technological, Not Physiological. Muniz-Pardos, B., Sutehall, S., Angeloudis, K. et al. Sports Med 51, 371–378 (2021).