The effect of an inclined landing surface on biomechanical variables during a jumping task
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Food and fluid intake and disturbances in gastrointestinal and mental function during an ultramarathon.
by
Glace BW, Murphy CA, McHugh MP.
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last modified
2009-10-09 15:16
Int J Sport Nutr Exerc Metab. 2002 Dec;12(4):414-27. Comment in: Int J Sport Nutr Exerc Metab. 2004 Jun;14(3):249-52; author reply 252-4.
The purpose of this study was to document eating strategies employed by runners
during a 160-km race, and to identify eating patterns that predispose the runner
to disturbed mental or gastrointestinal functioning. We monitored intake in 19
volunteers during the 12 hours pre-race. Intake was determined by interview with
runners approximately every 12 km throughout the race. The mean finish time was
24.3 hours, with 4 runners not completing the race. Body mass decreased during
the race, 75.9 +/- 2.3 kg to 74.4 +/- 2.2 kg (p <.001). Runners ingested 2643
kcals during the 12 hours prerace (68% carbohydrate) and 3.8 L of fluid. During
the race 6047 kcal, 18 L of fluid, and 12 g of sodium were consumed.
Gastrointestinal distress (GI) was experienced by half of the participants, but
was unrelated to food or fluid intake. Upper GI symptoms were more prevalent than
lower and occurred mainly after 88 km. Runners with GI distress tended to
complete fewer training miles (p =.10) and to do shorter training runs (p =.08).
Half of the volunteers reported mental status changes (MSC), such as confusion or
dizziness. Runners with MSC had greater intake of total calories, carbohydrate,
and fluid (p <.05) than runners without MSC. They also completed shorter training
runs (p =.03). Caloric and moisture intake for all runners far exceeded intakes
described previously. Although intake did not match energy expenditure, it may
represent the upper limit for absorption during exercise, and very high food
and/or fluid intake appears to lead to perturbed mental status.