The Sport Information Resource Centre
The Sport Information Resource Centre

The “aggregation of marginal gains” has become such a catchphrase that people have stopped questioning what it means. Science is meant to question, not to follow, and to look for the truth where it otherwise might be missed. What are “marginal gains”, really? Why have we been trained to look for them? How do they apply practically in high performance sport, if it all?

Marginal gains were originally discussed within the science and medicine staff at British Cycling in the early 2000’s as a way to try to be competitive with athletes who were consistently and substantially faster. How do you work towards a 10% improvement legally, safely and ethically? The strategy was to pursue multiple smaller gains that would accumulate to an equivalent gain.

Driving Innovation

Over the past decade, the concept has caused teams to chase every tiny gain available relating to nutrition, physiology, psychology, aerodynamics, and strength and conditioning. Olympic sports have looked to outside organizations and industries for things like data collection and analysis, aerodynamics, and even team management. For example, BAE Systems partnered with UK Sport to develop a high-tech ergometer for British Cycling. British Cycling has implemented a number of advances that built on knowledge and experience from Formula 1 racing, including a data collection “burger van” that sits permanently in the track centre at the Manchester Velodrome. Another area of substantial development across many sports has been with the analysis and interpretation of training data using specific software. Team Sky, for instance, partnered with Today’s Plan to develop their own customized version of the training software. This past decade sports have taken a huge step forward through innovation, much of it driven by partnerships with external experts with world-leading expertise in related areas that had never before been applied to sport.

In some cases, this drive for innovation has led to a perception that some teams are functioning almost robotically, with formulas and processes underlying every decision. In truth, sport is still about people and how to get the best out of them, so no algorithm or protocol will ever win a race. Regardless, the exploration of how and what to optimize within a sport is a fascinating approach to improving performance.

Debunking the Myths

Unfortunately, in the pursuit of marginal gains, teams have often ignored the costs with respect to time, energy, and resources. The leading teams have vast budgets not available to most amateur national sport organizations (NSOs) or even most professional teams, and yet there is still a pressure to replicate their level of innovation.

The teams that are being funded at the highest level can afford to pursue every possible improvement, but the rest of us need to be very selective with where resources are allocated; both financial and human resources. There is an opportunity cost to any potential innovation, and it is important examine that in detail before committing to a project. The likely gains should be large enough that they have a real-life effect on performance, and therefore need to be substantially larger than the measurement error of the instrument(s) being used to collect the data.

“Marginal” gains imply gains of 1-2%, however this magnitude of improvement is often within the margin of error, such as with commercially available cycling power meters that are accurate to within +/- 2.5%. Coaches and athletes can become frustrated with these kinds of interventions because they don’t see any impact on performance times in training or competition, despite the investment of time and money. Interventions such as altitude training have been extensively researched (Ploszczyca, Langfort, & Czuba, 2018), but it is unclear to some coaches whether the performance effect comes from the intended physiological alterations or from a highly focused training environment…or more likely a combination of the two. The value of getting a team together in a location where there is very little to do other than quality training and recovery, where people are monitoring training load and response to it with extra care, cannot be underestimated.

Marginal gains based on physiology depend on a number of assumptions that are very rarely true in sport. To realize these gains, athletes need to be optimally healthy, uninjured, eating an ideal diet, hydrating perfectly, coping ideally with the climate, recovering as fast as they can, and sleeping perfectly. This is uncommon in high performance sport, especially in the phase prior to competition when athletes are under stress and often have to travel.

If the current approach to marginal gains isn’t the answer, what is? As practitioners, we need to take a step back and look at the big picture. What makes a difference to performance at the highest level? Having your best athletes at the start line in great shape, instead of home injured or ill. Having a team of athletes who all want to be there and are in good mental health so they can give it their all. Having coaches and support staff who aren’t burnt out from trying to get all of the athletes to the competition in one piece while juggling their home life. Having a strong and efficient administrative system that provides the necessary logistical support to the team.

Investing in Real Gains

To improve performance, sport organizations, coaches and athletes need to look beyond the athlete and adopt a whole systems approach.

  1. Athlete Travel

Many NSOs in Canada have worked extensively with sleep specialists to ensure their athletes are sleeping optimally and have high quality plans for travelling across time zones to minimize jet lag. In addition to this, NSOs could implement travel booking guidelines to ensure athletes can fly at times that allow them to have a full night’s rest prior to the trip and fly the most direct route. Often this is not the cheapest option, and with limited budgets flights are often an area where organizations try to make savings. In some cases this may be fine, but when an athlete is targeting a top performance at an event the travel arrangements can have an impact (Reilly, 1990; Thun, Bjorvatn, Flo, Harris, & Pallesen, 2015).

One of the most frequently mentioned “marginal gains” to have come out of Team Sky and British Cycling is that they travel with their own mattresses. This is often ridiculed, however sleep quality is extremely important if an athlete is going to race hard every day for three weeks (Watson, 2017). Sleep quantity and quality play a role in preventing illness as well as in athletic performance and staying healthy through an entire three-week Grand Tour is a challenge. Team Sky’s approach is to not let chance determine if the bed is comfortable enough, if the hotel room is air conditioned, if the hotel food is adequate. They take these areas into their own hands, and while they may talk about them as “marginal gains” they are, in fact, quite significant.

  1. Mental Health

Mental health of athletes and staff is another area where the benefits are potentially quite large. Staff set the tone of the training and competition environment, and when they struggle it is often felt by everyone. Athletes who are struggling aren’t able to perform at their best, and it has been reported that the prevalence of mental health disorders in athletes is similar to that in the broader population (Gulliver, Griffiths, Mackinnon, Batterham, & Stanimirovic, 2015; Foskett & Longstaff, 2018). If an athlete is injured, teams know what to do and step in with interventions, but when someone is struggling mentally this is much harder to address. Canada has been lucky to have some well-known athletes speak up on this issue, however there is still much to be done in this area.

Organizations can address this area by having a comprehensive mental health strategy that establishes a consistent and positive approach to mental health issues in athletes and staff, and by providing mental health education to their coaches, support staff, and management. Morneau Shepell partnered with Cycling Canada in 2013 to develop and deliver sport-specific mental health education to their staff through an in-person workshop and a webinar, and participants reported a substantial improvement in their perception of awareness of mental health issues and treatment (unpublished data).

The Canadian sport system is making advances in mental health support for athletes with services such as Game Plan/Plan de Match as well as in-house services provided by National Teams. By having a strategy and providing education, NSOs can reduce the barriers of stigma and misunderstanding that may hinder people from reaching out to these services for the support they need.

  1. Bureaucracy

The importance of simple and efficient processes within the organization can’t be underestimated when it comes to optimizing race performance. Ensuring that people have all the information they need well in advance, that athletes have enough clothing for training and competition, that expenses are easy to file and people are reimbursed quickly, that communication between team members is easy and doesn’t overwhelm people with flooded inboxes, and many other areas of how the organization functions all have an effect on race day. This aspect of marginal gains has started to be studied in a scientific context (McGuire & Halliday, 2018), with studies examining how changing processes can have an effect on people rather than just looking at new types of interventions. This shows that the concept of marginal gains is valuable as a construct, in that it enables people to look at the entire system they work within and look for potential efficiencies and improvements.

Key Messages

The concept of “marginal gains” has been the catalyst for some substantial and positive innovations, as teams and organizations search for new areas of improvement that were not considered before. However, it is tempting to look for those gains only in terms of direct interventions with athletes, rather than turning that lens on the organization and systems that support the athletes. As a sport system, Canada needs to stay focused on all types of gains and resist the urge to search only for scientific interventions aimed at improving the performance of the athletes.

About the Author

Andrea Wooles is an exercise physiologist with nearly 20 years of experience working with Olympic and Paralympic sport. She began her career with British Cycling, consulted for numerous sports in the UK and Canada, and established the integrated support team system at Cycling Canada as their Science & Medicine Manager. She is now focusing on clothing and equipment innovations for Cycling Canada through partnerships with the team’s innovation partners.


Foskett, R., & Longstaff, F. (2018). The mental health of elite athletes in the United Kingdom. Journal of Science and Medicine in Sport, 21(8), 765–770.

Gulliver, A., Griffiths, K., Mackinnon, A., Batterham, P., & Stanimirovic, R. (2015). The mental health of Australian elite athletes. Journal of Science and Medicine in Sport, 18(3), 255–261.

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