Abstract
(Deutsch)
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1. Mannhart, C., and P. Colombani. Grundlagen der Sporternährung - die elementare Bedeutung der Energie-, Makronährstoff- und Flüssigkeitszufuhr. Schweizerische Zeitschrift für "Sportmedizin und Sporttraumatologie" 49(3): 125-30, 2001.
Zusammenfassung: Prinzipiell soll sich eine auf leistungsorientierte Personen zugeschnittene Ernährungsweise auch an den langfristigen, präventiven Ernährungsgrundsätzen (z. B. Schweizer Ernährungspyramide) ausrichten. In Abhängigkeit diverser Faktoren wie beispielsweise Alter, Geschlecht, Sportart, Trainingsvolumen, Trainingshäufigkeit, Leistungsintensität, Regenerationszeit und äusseren klimatischen Bedingungen muss allerdings versucht werden, kurz- und mittelfristig die Bilanzen im Bereich Energie-, Makronährstoff- und Flüssigkeitszufuhr ausgeglichen zu gestalten. Dadurch kann das Auftreten stark leistungslimitierender Faktoren wie Glykogendepletion, Hypoglykämie, Dehydratation minimiert werden. Eckpfeiler einer solchen Ernährung sind dabei in qualitativer Hinsicht eine bedarfsadäquate Zufuhr von Kohlenhydraten (ca. 6-10 g pro Kilogramm Körpermasse), Fetten (ca. 1.5 g pro Kilogramm Körpermasse) und Protein (ca. 1.5 g pro Kilogramm Körpermasse), die sinnvollerweise zeitlich auf die Vorleistungs-, Leistungs- und Regenerationsphase abgestimmt werden.
Abstract: A diet for physically active and performance-oriented people must also allow for any long-term preventive aspects of a healthy nutrition (e.g. according to the Swiss nutrition pyramid). Additionally, the energy, macronutrient and fluid balances must be met in a short- and medium-term range according to factors such as for example age, gender, sport type, exercise volume, exercise frequency, exercise intensity, regeneration, and environmental circumstances. In this way, the occurrence of performance limiting factors as glycogen depletion, hypoglycemia, or dehydration can be minimized. Cornerstones of such a diet are the consumption of about 6 to 10 grams of carbohydrates and each 1.5 grams of fat and protein per kilogram body mass. The nutrition must of course be closely timed with the exercise periods.
2. Colombani, P. C., and C. Mannhart. Ernährung im Sport. Therapeutische Umschau 57(3): 110-20, 2000.
Zusammenfassung: Die Basisernährung im Sport unterscheidet sich qualitativ kaum von der Ernährung eines gesunden Erwachsenen. Die energetische Verteilung der Makronährstoffe in Bezug zur gesamten Energieaufnahme sollte 55 bis 60 % Kohlenhydrate (hauptsächlich aus Lebensmittel mit tiefen glycämischen Index stammend), 10 bis 15 % Protein und 25 bis 30 % Lipide betragen. Im Breitensport richtet sich das Hauptaugenmerk in der Ernährung auf eine optimale Kohlenhydrat- und Flüssigkeitsaufnahme, den zwei wichtigsten leistungsbestimmenden Faktoren. Bei den Kohlenhydraten dürfte eine Aufnahme von 5 bis 7 Gramm pro Kilogramm Körpermasse genügen. In den Tagen vor und nach einer intensiven physischen Belastung sollte die Einnahme jedoch auf 10 g pro Kilogramm Körpermasse erhöht werden, um eine optimale Vorbereitung sowie Regeneration der Belastung sicherzustellen. Die basale Flüssigkeitsaufnahme beträgt etwa 2 bis 3 Liter pro Tag. Sie muss aber durch eine den schweissbedingten Verlusten entsprechenden Aufnahme von 1.2 bis 1.5 Liter pro Liter Schweiss ergänzt werden.
Abstract: A sports diet is qualitatively similar to a diet of a healthy adult. Its main aspects are meeting the energy and fluid requirements, which in contrast to sedentary people can vary to a large degree in sportsmen. The relative contribution of the macronutrients to the energy consumption should make up 55 to 60% carbohydrates (mainly derived from low glycemic food), 10 to 15% protein, and 25 to 30% fat. The main focus of a diet for most recreational sport activities should be on an optimal carbohydrate and fluid intake, which are the two main limiting factors of most physical activities. Related to the body mass, the carbohydrate intake should amount to 5 to 7 grams per kilogram. During the days before and after an intense exercise session or competition, however, the intake should be raised to about 10 grams per kilogram body mass to ensure an optimal energetic preparation of and regeneration from the exercise bout. The water intake should be about 2 to 3 liters per day with an extra 1.2 to 1.5 liters to balance each liter of exercise-induced sweat loss.
3. Colombani, P. C. , C. Mannhart, C. Wenk, and W. O. Frey. Nutritional intake during a 244 km multisport ultraendurance race. zur Zeit eingereicht beim European Journal of Sports Sciences.
Keywords: energy intake/energy balance/carbohydrate intake/exercise/sodium.
Abstract: The nutrition during ultraendurance competitions has mostly been described for case studies. We therefore investigate the nutritional intake during an extreme ultraendurance race on a larger scale. The ultraendurance multisport race was 244 km long (48 km mountain biking, 122 km road cycling, 28 km roller blading, 3.5 km swimming, 42.5 km running; total altitude difference ± 4000 m). 12 of the 25 subjects completed the race and their median (range) age was 34 (20-48) y. The race time of the finishers was 18.6 (17.0-19.8) hours. Energy intake during the race was 22.6 (12.4-33.6) MJ, which corresponded to 45 % of the estimated energy expenditure. Carbohydrate, protein, net fluid, and net sodium intake amounted to 60 (36-90) g·h-1, 0.8 (0.1-2.4) g·kg-1 body mass, 560 (310-790) mL·h-1, and 13 (7-19) mmol·L-1 net fluid intake, respectively. The nutritional intake during the race varied considerably among athletes and the intake of two target nutrients for ultraendurance athletes (i.e. fluid and sodium) was not optimal. Counseling of ultraendurance athletes should be enforced and strengthen the focus on an intake of drinks that also deliver sufficient sodium.
4. Vogt, M., A. Puntschart, H. Howald, B. Mueller, Ch. Mannhart, L. Gfeller-Tuescher, P. Mullis, and H. Hoppeler. Effects of dietary fat content on endurance performance, substrate selection and muscle composition in endurance trained men. zur Zeit eingereicht beim Medicine & Sciences in Sports & Exercise.
Keywords: muscle/exercise/high-fat diet/mitochondria/respiratory exchange ratio/human.
Abstract: The purpose of the present investigation was to identify differences in performance capacity, substrate selection and muscle structural composition in highly trained endurance athletes as a consequence of consuming either a high- or a low-fat diet. Eleven endurance trained duathletes ingested high-fat (53% of energy intake from fat; HF) or high-carbohydrate diets (17% fat energy; LF) for 5 weeks in a randomized crossover design. Maximal power and VO2max (63.6 vs. 63.9 ml O2/min*kg on HF and LF, respectively) during an incremental exercise test to exhaustion were not different between the two diet periods. Similarly, total work output during a 20 min all-out time trial (298 watts vs. 297 watts) on a bicycle ergometer as well as half-marathon running time (80 min 12 sec vs. 80 min 24 sec) were not different between HF and LF, respectively. Blood lactate concentrations and respiratory exchange ratios (RER) were significantly lower after HF than after LF at rest and during exercise at all power outputs up to VO2max. The difference in RER indicates a change in substrate selection towards a higher oxidation of fatty acids at all exercise intensities. Glycogen content (HF: 487.8 vs. LF: 534.4 mmol/kg d.w.) in skeletal muscle and muscle oxidative capacity estimated as volume density of mitochondria (HF: 9.86 vs. LF: 9.79%) were not different after the two diet periods whereas the intramyocellular lipid content was significantly increased after the high-fat diet (1.54%) compared to high-carbohydrate diet (0.69%).
In conclusion, we found endurance performance to be maintained at moderate to high exercise intensities after a 5 week high-fat diet with a significantly larger contribution of lipids to total energy turnover. The larger IMCL content together with similar glycogen stores in muscle cells after a high-fat diet being be of potential advantage in ultra endurance events.
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