Helping athletes reach their potential

Para swimming is Britain’s leading Paralympic sport. Biomechanics – the combination of physics and mechanics applied to the human body and its performance – is helping British swimmers find the best way to swim and creating a fairer system for classifying International Para swimmers for competition. 

Professor Carl Payton has led the research programme on swimming biomechanics at Manchester Met for over 20 years. 

He works extensively with British Para swimming coaches and swimmers at the National Performance Centre in Manchester, at training camps, and at international competitions including World Championships and Paralympic Games. 

His research has helped British swimmers collect record medal hauls and transform the way governing bodies classify swimmers for national and international competition. 

But how did Carl, a former competitive swimmer and coach himself, go from analysing swimmers in the pool to getting them in the right race and onto the podium at the biggest stages of all?  

“It all started with a phone call from the Director of British Para Swimming in 2000 (which was called Disability Swimming at the time) who asked whether I would be interested in working with their coaches and swimmers. I agreed despite knowing very little about disability sport. 

“It was daunting at first – it was very eye-opening. Very quickly, it became clear I wasn’t working with individuals with a disability; I was supporting elite swimmers who train as professionals and just happened to have a disability. All my techniques and knowledge gained from working previously with Olympic swimmers were transferable to this new group of athletes. It’s just grown from there into a fantastic relationship between the University and British Swimming/Para Swimming.” 

Swimming for gold 

Carl has been combining his two main areas of interest, swimming and science, ever since.

He has worked with the Great Britain Para swimming team since 2000 and attended the Sydney Paralympics that year. 

Using the science of biomechanics, Carl works with coaches and athletes to improve technique, choose the right swimsuits, and ultimately, enhance the performance of Great Britain swimmers.

“Much of my work is about optimising technique and the way swimmers move in the water,’’ says Carl. “To get the swimmers to make lasting technical changes in the water is challenging. They need to actually learn that technique so it becomes ingrained and automatic. The big challenge is bringing about that change. One of my PhD students is researching the optimum methods of teaching and learning skills in swimming –finding the best way for swimmers to make permanent changes and adaptations to their technique which remain robust in the face of fatigue and under the pressure of competition.”

Manchester Met’s biomechanics research seeks to understand how physical impairments influence technique, the propulsive forces that drive the swimmer forward, the drag forces that slow them down, and start and turn performance. 

The group has produced a substantial body of research in over 60 peer-reviewed scientific outputs since 2000. 

In a ground-breaking study on arm amputee swimmers, Carl’s team used a computer model to simulate the way water travels around a swimmer to see how much propulsion a partially amputated arm generates, and the factors that influence the magnitude of the propulsion.  

This study was the first to show that for any given swimming speed, the upper arm must reach a critical rotation speed to generate propulsion. Below this speed, the arm actually creates resistance, slowing the swimmer down. 

Carl was also the first to measure propulsive forces and fatigue in Para swimmers using tethered and semi-tethered force analysis and electromyography - a technique for evaluating the electrical activity produced by muscles. 

The findings show fatigue is not associated with the type or level of physical impairment. Para swimmers with limb deficiency, impaired power and impaired coordination can sustain propulsive forces when sprinting just as effectively as non-disabled swimmers. 

Britain’s leading coaches and elite swimmers have used the research findings to boost performances and the GB team’s medal achievements at major international competitions including the Beijing 2008, London 2012 and Rio 2016 Paralympic Games.  

UK Sport/British Swimming funded Carl to support Team GB’s preparation for the Rio 2016 Paralympics, and he received increased funding to continue the work for the 2016-20 Tokyo Paralympic cycle. 

Additionally, Carl has provided expert scientific support to every GB Para Swimming World Class Pathway athlete - a programme to support athletes with short and long-term potential for medal success - over the past 20 years. 

Race analysis 

“The support we provide during competitions is race analysis,’’ says Carl. “We film our swimmer’s races close up and then do a full statistical breakdown of how they performed. They have a Heat swim in the morning, we analyse the race and get the information back quickly so it can be used for the Final in the evening.

“We sit down with the coach and swimmer and review the swimmer’s race, how far they went underwater at the start, how many underwater kicks they did, whether their stroke rate was too high or too low at each stage of the race. We give them a detailed breakdown and, more often than not, we’ll spot one or two things they can tweak before the final and get that extra 1% improvement. 

“When I see someone’s technique improve or their race statistics change – I know I’ve played a part in that. It’s really satisfying. From an academic point of view, what an opportunity to conduct science on the best athletes in the world.

“A Paralympic Games is the pinnacle. It’s a completely different level in terms of the tension and the excitement, an order of magnitude bigger than the other events. To be part of that team is an honour.”

Great Britain topped the national ranking in the World Para Swimming (WPS) World Series in 2017, 2018 and 2019.  

Of the 321 Para swimming long course world records broken since 1 August 2013, 39 (12%) were by Team GB swimmers – the highest number by any country in this period. Carl provided evidence-based support to every single one of these swimmers. 

Marginal gains: every 0.62 seconds count 

Prior to the Rio Paralympics in 2016, Carl applied his drag research expertise to test the leading manufacturers’ swimsuits. 

He found drag differences of up to 10% between some suits, equating approximately to a one-second difference in a 100m race.  

From these findings, swimmers made informed decisions about which swimsuit to compete in and bespoke adjustments were made to some swimsuits to further reduce their drag. 

In the Women’s 4x100m Medley Relay at the Rio Paralympics, GB broke the world record by 0.98s, 0.62s ahead of Australia. 

The accumulation of marginal gains, including evidence-based swimsuit selection and adjustments, made the difference between gold and silver medals. 

The science behind classification 

At the London 2012 Paralympics, Carl got permission from the International Paralympic Committee (IPC) to do his first major classification project. His team were able to drag test Paralympic swimmers before and during the competition. 

The study found that within the more severe physical impairment classes some athletes had a substantially lower passive drag (resistance in streamlined position) than others in the same class - differences that could translate to a significant performance advantage. 

This was one of the first rigorous scientific studies to question the scientific underpinning - and therefore fairness - of the WPS classification system. 

In Para swimming, the athlete has to go through a classification process after which they are assigned to one of 14 classes, so they have an equal chance of winning the race against their competitors.

Carl explains: “It should not be the level of impairment that determines the outcome of a race. Your impairment should not advantage or disadvantage you. There’s been considerable disquiet and controversy around sport classification, there’s a big push by the IPC to conduct research and revise all the classification systems. That’s where my work comes in – to provide the evidence to develop something more objective, fairer and less controversial.

“The sport has changed so much - the professionalism, funding and performances. These athletes train four hours a day in the pool, an hour a day in the gym, some of them are swimming 50,000 to 60,000 metres (up to 60km) a week. They are serious athletes. Worldwide, the sport has become professionalised. In some respects, the classification system hasn’t kept pace.”

Improving the system

In 2016, the IPC approached Manchester Met and the University of the Sunshine Coast in Australia to improve the World Para Swimming classification system that defines race categories of physically impaired swimmers. 

The project has collected data from more than 150 Para and non-disabled swimmers in the UK and overseas – the largest ever study cohort of its kind. 

“We look at a swimmer’s condition – be that cerebral palsy or a spinal cord injury - and we only test or measure the factors associated with that condition,’’ says Carl. 

“For example, for a swimmer with a limb deficiency such as an arm amputation, we wouldn’t test their strength, we wouldn’t test their coordination, because actually having a limb amputation shouldn’t affect those things. Whereas someone with a motor impairment such as hypertonia may have coordination, strength and range of motion affected. The classification should address those three areas to determine the extent to which the swimmer’s impairment is preventing them from doing the things required to swim fast. We are moving towards much more quantitative, measurement-driven ways of classifying swimmers.” 

Subjective assessments can discriminate against elite athletes whose superior training puts them in a higher class than some competitors with the same level of impairment, but who train less. 

The WPC and the IPC can now develop a classification system based on objective measurements rather than on expert, but subjective, opinion.  

The new system will be mandatory and adopted for all competitions from local and national meets to World Championships and the Paralympics. 

With such a distinguished career and a sustained impact on competitive Para swimming, is there a particularly proud moment that sticks out for Carl? 

“I’m proud to be part of the team, and my longevity I suppose. There aren’t that many sports scientists who’ve had such a long involvement with a national sports team. I’m proud of my track record. 

“People sometimes perceive biomechanics as being hard because of its links with maths and physics; they immediately put up a barrier to it. But I think these two projects are great examples of biomechanics in action, being applied in the real world and having an impact. Ultimately, I do it because it’s challenging and fun. And the work we’re doing here is having a real effect on our elite sports people, at a national and international level.”