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For many WorldTour riders, the Spring Classics period is the pinnacle of their season. Months of training, attention to detail with equipment selection, and knowing the race routes back-to-front have the riders as ready as they can be. But nutrition isn’t something that gets talked about a lot around the Classics season.
For all the attention on what riders eat before, during and after stages in the Grand Tours, it’s surprising how little focus the Classics get. Due to the long race distances and aggressive racing, even the flatter one-day races can take as much fuelling as a high mountain stage of a major tour.
And it’s easy to forget that many riders will complete as many as four races in eight days during the period between Milan-San Remo and the Tour of Flanders, which is exactly what six riders from Mitchelton-Scott did last year. And a new study has just been published, showing how these riders fared with their nutrition during the 2018 classics season, and the effect this had on their bodies.
This study, involving researchers from Australian Catholic University, the Australian Institute of Sport, Aspetar Sports Medicine & Orthopaedic Hospital in Qatar, Nottingham Trent University in the UK, and of course the Mitchelton-Scott team, followed six of the team’s riders over nine days.
During this period they competed in four one-day races: Driedraagse de Panne, E3 Harelbeke, Gent-Wevelgem and Dwaars door Vlaanderen. All of these races except for Dwaars door Vlaanderen were over 200km in length, and most contained significant climbs, many of them cobbled. The riders diligently collected food diaries throughout this period, and had blood samples taken before and after the block of racing.
Eating for the work required?
To borrow a phrase from Team Sky nutritionist James Morton, athletes should ideally “fuel for the work required” – that is, adjust the amount of food (particularly carbohydrate-rich foods) based on training or racing demands (previously explained here).
In this study it looks like this certainly did happen. From 7pm the night before each race to 7pm after the race, riders ate on average 6,216 calories (kCal), or 26,000kJ, and 10.7 grams per kg of body weight of carbohydrate. On rest days they ate 5,050 calories (21,129kJ) but only 6.4 grams per kg of carbs. For context, the average, lightly active male will typically eat around 2,100-2,870 calories (9,000-12,000kJ) per day when not focussing on weight gain or loss.
Whilst 6.4 grams per kg sounds like a lot of carbs for a rest day, bear in mind that these guys were often not only recovering from a race the day before, but beginning to fuel for another one the next day.
During the races, riders maintained an average carbohydrate intake of 51 grams an hour. This is significantly less than what’s often reported for similarly tough days in Grand Tours. The reason may be due to the hectic nature of one-day races, with any combination of crosswinds, road furniture, and cobbled climbs restricting the opportunities for riders to eat and drink, compared to the more frequent sedate periods in stage racing.
Another finding from the study was that the amount of protein eaten by the riders was very high, well above official sports nutrition guidelines (around 1.6g per kg per day). On race days the riders ate on average 2.8 grams of protein per kg body weight, and 3.3 grams per kg on the rest days. These values reflect partly the sheer volume of food that’s being consumed, but possibly also an emphasis on protein from a muscle recovery, repair and adaptation perspective (see here for previous explanation).
By way of comparison, Team Sky typically aim for 2-2.5 grams per kg on a daily basis during stage racing.
The researchers weren’t just interested in how riders adjusted their eating between racing and rest days. They were also interested to see how this was reflected in energy availability (the amount of calories eaten that are available to fuel normal bodily functions, after accounting for the calorie cost of exercise — see here for a more detailed explanation), and the health implications of failing to match nutrition to the demands of racing during this period.
Energy availability was measured from the riders’ food records (intake) and power meter data (expenditure), and is calculated in calories per kg of fat free mass (kCal/kg FFM). Generally speaking, a value of less than 30 kCal/kg FFM is considered low energy availability, and it is when people are consistently below this level that performance and health implications of under-eating, relative to exercise demands, tend to become apparent. This is known as Relative Energy Deficiency in Sport, or RED-S.
Not surprisingly, during this period of the Classics season, every rider had an energy availability less than 30 kCal/kg FFM on race days (average 14.4) due to the demands of these races (energy expended was over 5,000 calories (20,920kJ) per race), and the limited time to compensate for this off the bike. On recovery days, every rider exceeded the 30kCal/kg FFM mark (average 57kCal/kg FFM), because although they ate about 1,000kCal (4,184kJ) less than race days, the reduction in energy expended on the bike was far greater (~4,200kCal (17,570kJ) less compared to race days).
When considered over the whole eight-day block of racing, half the riders did not adequately compensate for the nutritional demands of racing on recovery days, ending the entire period with an average energy availability of 28kCal/kg FFM per day, compared to 43kCal/kg FFM per day in the other riders. And this difference showed in their blood results, with a reduction of 14% in testosterone and 25% in IGF-1 (another hormone that tends to be reduced with under-eating relative to exercise demands) in the riders with energy availability below recommendations. The other riders saw a 7% increase in testosterone and 5% increase in IGF-1.
These disturbances in hormonal function are not ideal, and although an eight-day period is not enough to draw firm conclusions, it is likely that if this pattern of racing and recovery with inadequate nutrition continued for longer, the impairments in health and/or performance known to occur in RED-S would become apparent.
Lessons for the amateur cyclist
The pattern of racing that the pros undertake in the Spring Classics is fairly unique – there’s not many situations where amateur riders will compete in long, hard races every second or third day for a week or more. Perhaps this pattern of effort may be more likely in an intensive training block rather than several big mid-week and weekend races.
Either way, the take-home messages for the amateur cyclist would be:
– If you’re going to be doing frequent long, hard rides in an intensive block, it’s likely this will significantly reduce your energy availability unless you consciously compensate by eating substantially more during this period.
– Make sure you compensate by increasing how much you eat not only on the bike, but before and after racing, and even the next day.
– Restricting what you eat relative to training to achieve rapid weight loss can increase your risk of RED-S, and a variety of short and long-term health and performance consequences.
– If you’re struggling to physically cope with training demands, consider seeking professional help to identify if your nutrition is adequate.
About the author
Alan McCubbin is an Accredited Sports Dietitian, Accredited Practicing Dietitian and past president of Sports Dietitians Australia. He is currently studying his PhD in sports nutrition at Monash University. He is also the founder of Next Level Nutrition, an online sports nutrition consultancy through which he works with a range of athletes from recreational to Olympians.