REF-855 · Bescós et al., 2012 · Journal of the International Society of Sports Nutrition, Vol. 9, article · Paper · PubMed
Nutritional behavior of cyclists during a 24-hour team relay race: a field study report
All food and fluid taken by eight men during a 24-hour team relay cycling race were weighed and recorded, and energy expenditure was estimated from individual heart rate-VO2 regressions set in a pre-race incremental test. The riders took in far less energy than they spent, even though their carbohydrate, protein and fat intake did not differ from the guidelines for long events. None of the nutritional variables was related to the distance or speed each rider achieved.
Participants
n=8 men (abstract: "eight males"): 36.7 ± 4.7 years, 71.6 ± 4.9 kg, 174.6 ± 7.3 cm, BMI 23.5 ± 0.5 kg/m2. Training history and team structure (number of riders per team, turn length) are not given in the abstract.
Protocol
Before the race: incremental exercise test to build two heart rate-VO2 regression equations per rider, used to estimate energy expenditure.
During the 24-hour team relay race: all food and fluid weighed and recorded; distance and speed of each rider recorded.
Intake compared with current nutritional guidelines for endurance events; correlations between nutrition and performance variables.
Key Results
| Measure (whole event, per rider) | Value |
|---|---|
| Carbohydrate | 943 ± 245 g (13.1 ± 4.0 g/kg) |
| Protein | 174 ± 146 g (2.4 ± 1.9 g/kg) |
| Fat | 107 ± 56 g (1.5 ± 0.7 g/kg) |
| Energy intake | 22.8 ± 8.9 MJ |
| Estimated energy expenditure | 42.9 ± 6.8 MJ (intake significantly lower, P = 0.012) |
| Fluid | 10497 ± 2654 mL |
| Caffeine | 142 ± 76 mg |
No relationship between the main nutritional variables (energy intake, carbohydrate, protein, fluid, caffeine) and the main performance variables (distance, speed).
Macronutrient intake did not differ from the nutritional guidelines for longer events; the energy demand was still not covered.
Practical Application
In eight men riding a 24-hour team relay, weighed intake over the event was 943 g of carbohydrate (13.1 g/kg) and 22.8 MJ in total, against an estimated 42.9 MJ spent (P = 0.012), and how much a rider ate or drank did not relate to how far or how fast he rode. To "can I eat enough in a 24-hour relay?": even riders whose macronutrients matched the guidelines covered only about half the cost, so expect a deficit and plan to limit it rather than to erase it.
Inference, not tested here: in a relay the time off the bike between turns is the time to eat real food; the abstract does not say when the riders ate, so this is not a result of the study.
The lack of a link between intake and distance is a small-sample null in eight riders, not evidence that fuelling does not matter.
Limitations
n=8 men in one event; relay format, so each rider's riding time is only part of the 24 hours.
Energy expenditure was estimated from heart rate-VO2 regressions, not measured; the size of the deficit carries that error.
The timing of intake across the 24 hours and the turn structure are not given in the abstract.
Written from the abstract and record metadata only (full text not read).
How this entry was checked and changed
Why this level
descriptive field study, n=8, one event