How These Elite Cyclists Gained 100 BC Points By Fuelling

It should come as no surprise that in cycling, power to weight ratio is a key determinant of performance. Look at the podium of many cycling races and you’ll likely see a lean athlete who’s able to produce high work rates.

As such, it comes as little surprise that many athletes look to optimise their body compositions through fat loss in the pursuit of increased performance. 

Due to the potential to improve performance and the culture within the sport, cyclists and coaches are often preoccupied with following disciplined training diets and pursuing weight loss, with weight loss often being a go-to performance enhancer.

However, the downsides of pursuing weight loss are rarely discussed or taken into account when selecting this as a tool for performance enhancement.

For a number of reasons, the pursuit of weight loss can actually lead to a significant reduction in performance and significantly negatively impact an athlete’s health. 

To achieve weight loss we need to be in a calorie deficit, whereby we expend more energy than we take in through food. Endurance athletes often end up in a calorie deficit in one of two ways.

1. The conscious restriction of energy intake through reducing food intake.
2. Inadvertently not consuming sufficient energy to meet the demands of their training/competition. 

Energy availability refers to the calories that an athlete has left once their energy expenditure from exercise has been taken into account and is the energy left to support normal physiological function.

For example, on a given day, if an athlete completes a hard training session that expends 2000kcal during the training session alone, but only consumes 2500kcal within that day, their energy availability is a mere 500kcal. This then leads to a suppression of many of the processes associated with normal health, like growth, repair and reproduction.

Long-term periods of low energy availability can result in RED-S. Referred to as relative energy deficiency in sport (REDs for short), the syndrome is associated with a number of negative effects on an athlete’s health and performance, as illustrated here..

A number of high-profile examples of athletes who have experience RED-S have been reported within the media, with athletes often experiencing serious negative health consequences. 

• Bobby Clay - My osteoporotic nightmare 
• Lionel Sanders - Ironman athlete weight obsession
• Ben King - Pro cyclists bulimia battle
• BBC Three - The weight cut: Extreme weight loss documentary
• Evie Richard - World champion mountain biker & RED-S


A growing body of sports science research is now also illustrating to us why the pursuit of weight loss (and resultant cumulative low energy availability state that many athletes end up in) isn’t always performance enhancing, and why athletes potentially stand to gain more from optimal fuelling their training and racing than they do trying to lose a few kgs. 

A great illustration of this, particularly in the sport of road cycling, comes from a fascinating study by Endocrinologist Dr Nicky Keay and colleagues in 2019.

 The study took 45 male cyclist who where Category 2 and above, including a number of Elite World Tour Cyclist.

The riders were screened at the start and end of the race season for their performance using a functional threshold power test, bone health (a key indicator of low energy availability, insufficient energy = poor bone health) using a DEXA scan and their energy availability using a questionnaire and interview. They also had blood taken for screening of metabolic and endocrine markers, which can help with the diagnosis of REDs (i.e. low testosterone is associated with low energy availability)

They were then divided into pairs matched for their bone health results, with one from the pair left to their own devices for the season and the other given an educational intervention around how to optimally approach their training nutrition, with a focus on optimal fuelling to avoid them being in low energy availability combined with some exercises designed to load the skeleton in an effort to improve bone health (Cyclists generally have poor bone health due to a lack of skeletal loading and at times low energy availability).  

At the end of the season, the athletes returned to the lab and were screened again. Despite the instructions from the study, many athletes didn’t follow the advice they were given, so the numbers didn’t quite match the original plan. However, the follow-up revealed some interesting findings… 

1. The eleven cyclists who made positive changes to their nutrition behaviours and off-the-bike exercise reported improved well-being and feeling stronger on the bike. 
2. Although no athletes in the study were told to reduce their nutrition intake or off-bike exercise, nine athletes did so in the belief that it would improve their performance, but all reported fatigue, illness, and injury. 
3. Increasing off-the-bike exercise and nutrition intake resulted in improvements in the athlete’s bone health, whilst reducing off-the-bike exercise and nutrition intake did the opposite. 
4. The results suggested that improving energy availability was worth 95 British Cycling Racing points, whereas restricting nutrition cost 95 points.

So in effect, if you’re a relatively lean athlete already who performs at a high level and you want to improve your performance, feel better on the bike, improve your bone health, and reduce your risk of illness and injury then you’d be better focusing on optimally fuelling your training and competition than the pursuit of weight loss. 

- Coach Ben

Keay N, Francis G, Entwistle I, Hind K. Clinical evaluation of education relating to nutrition and skeletal loading in competitive male road cyclists at risk of relative energy deficiency in sports (RED-S): 6-month randomised controlled trial. BMJ Open Sport Exerc Med. 2019;5(1):e000523. Published 2019 Mar 29. doi:10.1136/bmjsem-2019-000523