Nutrition for Cycling - Energy Availability

Michaela Rogan is our Road Ambassador and off the bike, she’s an Associate Registered Nutritionist. Michaela has been working on a series of blog posts to build more awareness around nutrition, and get people thinking about how they can best fuel their riding endeavours.

One blog has already been written on the basics of nutrition, and here this blog is taking a deeper dive into energy intake and expenditure.

One of the biggest nutritional challenges for cyclists of ANY level is matching energy intake to the energy demands of cycling. Energy availability has become an important concept for people who exercise and is defined as the energy remaining from dietary intake, after accounting for the energy expenditure of exercise, expressed relative to fat-free mass. Which is quite a mouthful, but it essentially represents the calories available to the body to keep tissues and organs functioning properly – the reproductive system, immune system, skeleton, brain, metabolism etc. It’s expressed relative to fat-free mass (everything in the body that isn’t fat: muscle, organs, bones etc.) because these “metabolically active” tissues are really what we need the energy for, and those with more fat-free mass require more energy to maintain optimal body function.

Low energy availability (LEA) is a type of mismatch between energy intake and energy expenditure and is the underlying cause of a condition called ‘Relative Energy Deficiency in Sport’ (RED-S). When the body doesn’t receive enough energy from the diet to keep everything ticking over optimally, it will direct energy towards processes essential to short-term survival, and down-regulate whatever else it can. It’s not thinking about reproduction, and it’s certainly not thinking about maximising physiological adaptations to training. While body fat stores hold huge reserves of energy, LEA doesn’t necessarily equate to weight loss – that’s probably not sustainable in the long-term (the body can actually hold onto more fat in the anticipation of, presumably, a famine).

Consequently, RED-S can wreak havoc on nearly every single body system, including impairments in bone, gastrointestinal, cardiovascular, endocrine, metabolic, immune, and psychological health - repercussions that if not immediately concerning, will certainly become problematic months, years, and decades later. Performance-wise, LEA can decrease endurance, muscle strength, training response, and glycogen storage; impair concentration, coordination, and judgement; and increase illness, injury risk, and irritability. Which is basically a giant list of everything you don’t want if you want to get better at riding your bike and have fun doing it.

Accurately measuring energy availability is incredibly difficult, there are many nuances to how it is calculated (a diagnosis of full-blown RED-S requires a multi-disciplinary team and a barrage of different assessments), but there are many objective parameters that can be useful indications of LEA risk. If you are a female of reproductive age, and not on hormonal contraception, the menstrual cycle is an important barometer: not having regular periods is neither normal, nor healthy, and don’t let anyone convince you otherwise. Be aware of changes in cycle length, bleeding duration, and flow, which often occur before periods disappear altogether (which we want to avoid). While testosterone also takes a hit in males with LEA, this isn’t so blatantly obvious. If you are experiencing one or more of the following, you may be under-fuelling:

• Low mood/irritability
• Persistent fatigue
• Lack of motivation to exercise
• New or persistent gut problems
• Always feeling hungry
• Weight loss OR inability to alter body composition
• Menstrual cycle changes (shorter cycle, lighter periods, irregular or absent periods)
• Reduced libido
• Frequent illness
• Frequent injury and/or long rehab
• Failing to adapt to training, plateauing performance, or decrease in performance

 

Ultimately, if you don’t have adequate energy availability, then you aren’t getting the most out of every other aspect of your nutrition, let alone your training. Protein intake will only be used for muscle repair and growth if your carbohydrate and energy needs are being met, otherwise, the body will convert that protein to energy to fuel other body processes. Un-repaired muscle can then impair muscle glycogen storage, impairing future performance, on top of the fact that carbohydrate intake may already be suboptimal. Disruptions in reproductive hormones can reduce bone density, often beyond repair (we want to bounce, not break when we inevitably fall off our bikes), and if you are the one who always picks up a cold when it’s going around, you can throw the concept of “consistency” out the window.

It can be difficult to recognise or accept that the reason your performance is plateauing despite training hard, you are frequently sick, and are bloated after every meal is due to under-fuelling, especially if you haven’t been losing weight. Many people have the false perception that only super-lean high-level athletes with massive training volumes are vulnerable to LEA, but both males and females across the entire spectrum of recreational exercisers to professional athletes, of ANY body type can be affected. The risk may even be higher for recreational athletes, who may not have the nutritional knowledge or professional support that elite athletes might, and also have to balance the time and stress of work, study, or a family alongside their sport.

While disordered eating is undoubtedly a huge and unfortunately, prevalent, issue in exercising populations (cycling in particular has a long-standing complicated relationship with food, weight, and body composition), LEA can very easily occur unintentionally. Increasing exercise volume without sufficiently adapting food intake (something that as a species, humans are just not that good at doing intuitively), appetite changes around exercise, lack of time or motivation to prepare food, and the financial burden of feeding a hungry cyclist can all factor in. 

A key strategy to ensuring adequate energy availability is to really focus on pre, during, and post-exercise fuelling. If you are having regular balanced meals throughout the day, but then making sure you are always topped up before a ride, having regular snacks on the bike, and then having a solid recovery meal after every session, this will help adapt your dietary intake to fluctuating exercise demands across the week or months. Sports nutrition is often at odds with public-health guidelines for the general population, but it’s important to acknowledge that as someone who regularly rides their bike, your nutritional demands are different: expect to have more snacks or meals throughout the day, and eat more than your friends, family, or flatmates when you sit down for a meal. The moment you start viewing nutrition as a means to get the most benefit and enjoyment from your riding and truly “fuel for the work required” (rather than solely as a means of weight control or something that is not even on your radar), the difference is truly mind-blowing. You can FEEL it.

So, stay tuned for the next blog posts, which will go into the nuts and bolts of exactly what to eat before, during, and after a ride to avoid LEA, and meet your nutritional needs as a cyclist.

 

Michaela Rogan

Associate Registered Nutritionist