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More Training Info > Research - Hill Walking Performance Implications
Physiological, metabolic, and performance implications
of a prolonged hill
walk: influence of energy intake.
Summary of original research from Ainslie PN, Campbell IT, Frayn KN, Humphreys SM, MacLaren DP, Reilly T. “Physiological, metabolic, and performance implications of a prolonged hill walk: influence of energy intake.” J Appl Physiol 2003 Mar; 94(3): 1075-1083.
Trying to reduce bodyfat or lose a little weight in preparation for the upcoming climbing season? Take a look at the following study of performance among hill walkers and our recommendation, below:
The Study: This study aimed to examine the effects of different energy intakes on a range of responses that are relevant to the safety of hill walkers. In a balanced design, 16 men completed a strenuous self-paced mountainous hill walk over 21 km, under either a low-energy (2.6 MJ; 616 kcal) intake (LEI) or high-energy (12.7 MJ; 3,019 kcal) intake (HEI) condition. During the hill walk, rectal temperatures were measured continuously, and blood samples for the analysis of metabolites and hormones were drawn before breakfast and immediately after the walk. Subjects also completed a battery of performance tests that included muscular strength, reaction times, flexibility, balance, and kinesthetic differentiation tests.
The Results: The LEI group showed significantly slower one- and two-finger reaction time, had an impaired ability to balance, and were compromised in their ability to maintain body temperature, when compared with the HEI group. The modestly impaired performance (particularly with respect to balance) and thermoregulation during the LEI condition may increase susceptibly to both fatigue and injury during the pursuit of recreational activity outdoors.
The Take-Home Message: If you’re on any sort of restricted calorie diet (including Atkins, The Zone, Sugar Busters, Pritikin, Weight Watchers, Jenny Craig and others—anything that significantly reduces your daily consumption), or you use weekend exercise (combined with low intake) as a way to counteract a week of indulgences and lack of activity, your performance (coordination, balance, and endurance) will almost certainly suffer.
Body Results Suggests: Allow yourself a day or two of increased caloric consumption (choosing the right foods, of course, and appropriate to your bodyweight and hence metabolic requirements) in preparation for endurance outings such as hikes, climbs, high-altitude or winter excursions that are going to take you into colder temperatures and require a higher degree of coordination, mental sharpness and balance. Then return to your reduced intake nutrition plan the other 5 days of the week in order to keep performance levels high while still getting the nutrition results you desire.