Baylor University Medical Center Proceedings January 2014, Volume 27, Number 1 | Page 44

Energy and macronutrient intake of a female vegan cyclist
during an 8-day mountain bike stage race
Katharina C. Wirnitzer, Dr. rer. nat., and Elmar Kornexl, Univ.-Prof.

This report describes the dietary intake of a vegan mountain biker (height,
161 cm; weight, 49.6 kg; body mass index, 19.1 kg/m2; relative peak
power output, 4.6 W/kg) during the Transalp Challenge 2004 (altitude
climbed, 22,500 m; total distance, 662 km), illustrating an aggressive
dietary strategy that allowed the cyclist to be competitive. She finished
the 8-stage event in 42 hours (mixed category, rank 16; 514 minutes
behind the winners of this category), cycling with an average heart rate
of 79.5% of laboratory-determined maximum, spending 892 minutes and
1627 minutes at intensities below and above 80%, respectively. During
racing, the consumption of energy was 69.3 MJ (1.65 MJ/h), 65.76 MJ
from carbohydrates (92 g/h), which was 35% of calories and 40% of
carbohydrate total intake, and the fluid ingested was 3 L/day (570 mL/h),
55% of the total fluid consumed.

ountain bike marathon stage races are very popular,
with events such as the Transrockies Challenge attracting thousands of recreational, elite, and professional athletes. Although there are established
nutritional guidelines for road cyclists (1, 2), the physiological
demands of mountain bike competitions differ markedly from
those of road cycling (3, 4), and for this reason the nutritional
strategies might differ. Not only are the number of women participating in mountain bike stage events increasing, but probably the number of vegan cyclists is increasing too, given the
background numbers of vegans. However, it is difficult to find a
group of vegan cyclists participating in the same competition for
large sample size studies. Contrary to the belief that the vegan
diet is not optimal for athletes, we present the case of a woman
who successfully completed a challenging mountain bike stage
race while following a vegan diet.

M

CASE DESCRIPTION
One endurance-trained female amateur mountain biker
(age, 30 years; height, 161 cm; weight, 49.6 kg; body mass
index, 19.1 kg/m2; iron, 105 μg/dL [norm: 60–150 μg/dL];
ferritin, 133 ng/mL [norm: 15–150 ng/mL]; hemoglobin, 14 g/
dL [norm: 12–16 g/dL]; hematocrit, 41% [norm: 35–49%];
vitamin B12, 280 pg/mL [norm: 200–950 pg/mL]; homocysteine, 7 μmol/L [norm: <14 μmol/L]) was recruited for this
case report. She had successfully followed a vegan diet (rejecting
all products from animal sources) since 1999 and had 16 years
42

of experience in mountain bike sports, including participating
in ultramarathons and stage races. In 2004 she started the Transalp Challenge (TAC) for the second time, having previously
completed it in 2003.
TAC is a demanding 8-day race (5) requiring a cyclist to
climb a total altitude of 22,500 m and ride a total distance of
662 km. For safety reasons, athletes have to compete in double
teams. A total of 1074 professional and amateur mountain bikers participated in the TAC 2004, and winners in all categories
were professional mountain bikers. In the TAC 2004, the overall
winning team (men’s category) finished in 29 hours, 21 minutes,
and 9 seconds.
To prepare for this multiday race, the rider trained for
about 25 hours per week for almost a year. She performed an
incremental laboratory cycling test (started at 100 W, with
workload increased by 30 W every 5 min) on an electromagnetically braked ergometer (SRM GmbH, Jülich, Germany)
before the start of the event. Relative peak power output
(PPO) was 4.6 W/kg. During the race, her heart rate (HR)
was continuously recorded, and data were analyzed using software (S710 and 4SW, Polar Electro Oy, Kempele, Finland).
The relative intensity of exercise was expressed as percentage of
laboratory-determined maximum HR (HRMAXLab: 182 bpm)
and absolute PPO (PPOABSOLUTELab: 230 W). After each
stage of the race, her body mass was measured and she rated
how hard the race was overall, using Borg’s rate of perceived
exertion (RPE) scale.
The female mountain biker finished in 41 hours, 59 minutes, and 45 seconds, achieving a final ranking of 16th place
within the mixed category. Time spent in HR rang