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Acute and sustained effects of a periodized carbohydrate intake using the sleep‐low model in endurance‐trained males
Author(s) -
Riis Simon,
Møller Andreas Buch,
Dollerup Ole,
Høffner Line,
Jessen Niels,
Madsen Klavs
Publication year - 2019
Publication title -
scandinavian journal of medicine and science in sports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.575
H-Index - 115
eISSN - 1600-0838
pISSN - 0905-7188
DOI - 10.1111/sms.13541
Subject(s) - endurance training , lipolysis , carbohydrate metabolism , endocrinology , medicine , carbohydrate , mitochondrial biogenesis , time trial , chemistry , heart rate , biochemistry , adipose tissue , mitochondrion , blood pressure
Repeated periodization of carbohydrate (CHO) intake using a diet‐exercise strategy called the sleep‐low model can potentially induce mitochondrial biogenesis and improve endurance performance in endurance‐trained individuals. However, more studies are needed to confirm the performance‐related effects and to investigate the sustained effects on maximal fat oxidation (MFO) rate and proteins involved in intramuscular lipid metabolism. Thirteen endurance‐trained males (age 23‐44 years; V ˙ O 2 ‐max, 63.9 ± 4.6 mL·kg −1 ·min −1 ) were randomized into two groups: sleep‐low (LOW‐CHO) or high CHO availability (HIGH‐CHO) in three weekly training blocks over 4 weeks. The acute metabolic response was investigated during 60 minutes of exercise within the last 3 weeks of the intervention. Pre‐ and post‐intervention, 30‐minute time‐trial performance was investigated after a 90‐minute pre‐load, which as a novel approach included nine intense intervals (and estimation of MFO). Additionally, muscle biopsies ( v. lateralis ) were obtained to investigate expression of proteins involved in intramuscular lipid metabolism using Western blotting. During acute exercise, average fat oxidation rate was ~36% higher in LOW‐CHO compared to HIGH‐CHO ( P = .03). This did not translate into sustained effects on MFO. Time‐trial performance increased equally in both groups (overall time effect: P = .005). We observed no effect on intramuscular proteins involved in lipolysis (ATGL, G0S2, CGI‐58, HSL) or fatty acid transport and β‐oxidation (CD‐36 and HAD, respectively). In conclusion, the sleep‐low model did not induce sustained effects on MFO, endurance performance, or proteins involved in intramuscular lipid metabolism when compared to HIGH‐CHO. Our study therefore questions the transferability of acute effects of the sleep‐low model to superior sustained adaptations.