Effect of short-duration lipid supplementation on fat oxidation during exercise and cycling performance
| Autor: | Dominik Grathwohl, Fabio Borrani, Philippe Pollien, Virgile Lecoultre, Jacques Décombaz, Jeroen A. J. Schmitt |
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| Rok vydání: | 2013 |
| Předmět: |
medicine.medical_specialty
Physiology Endocrinology Diabetes and Metabolism Physical activity chemistry.chemical_compound Oxygen Consumption Fat oxidation Physiology (medical) Internal medicine Mental stress medicine Dietary Carbohydrates Humans Intramyocellular lipids Short duration Exercise Nutrition and Dietetics Glycogen Skeletal muscle General Medicine Dietary Fats Bicycling Endocrinology medicine.anatomical_structure chemistry lipids (amino acids peptides and proteins) Cycling |
| Zdroj: | Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 38(7) |
| ISSN: | 1715-5320 |
| Popis: | The effect of intramyocellular lipids (IMCLs) on endurance performance with high skeletal muscle glycogen availability remains unclear. Previous work has shown that a lipid-supplemented high-carbohydrate (CHO) diet increases IMCLs while permitting normal glycogen loading. The aim of this study was to assess the effect of fat supplementation on fat oxidation (Fox) and endurance performance. Twenty-two trained male cyclists performed 2 simulated time trials (TT) in a randomized crossover design. Subjects cycled at ∼53% maximal voluntary external power for 2 h and then followed 1 of 2 diets for 2.5 days: a high-CHO low-fat (HC) diet, consisting of CHO 7.4 g·kg(-1)·day(-1) and fat 0.5 g·kg(-1)·day(-1); or a high-CHO fat-supplemented (HCF) diet, which was a replication of the HC diet with ∼240 g surplus fat (30% saturation) distributed over the last 4 meals of the diet period. On trial morning, fasting blood was sampled and Fox was measured during an incremental exercise; a ∼1-h TT followed. Breath volatile compounds (VOCs) were measured at 3 time points. Mental fatigue, measured as reaction time, was evaluated during the TT. Plasma free fatty acid concentration was 50% lower after the HCF diet (p0.0001), and breath acetone was reduced (p0.05) "at rest". Fox peaked (∼0.35 g·kg(-1)) at ∼42% peak oxygen consumption, and was not influenced by diet. Performance was not significantly different between the HCF and HC diets (3369 ± 46 s vs 3398 ± 48 s; p = 0.39), nor were reaction times to the attention task and VOCs (p = NS for both). In conclusion, the short-term intake of a lipid supplement in combination with a glycogen-loading diet designed to boost intramyocellular lipids while avoiding fat adaptation did not alter substrate oxidation during exercise or 1-hour cycling performance. |
| Databáze: | OpenAIRE |
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