handdator

Visa fullständig version : Glykogentillgänglighet och träningsförmåga vid upprepad ansträngning


King Grub
2015-12-17, 09:33
Purpose:

This study aims to examine whether muscle glycogen availability is associated with fatigue in a repeated exercise bout following short-term recovery.

Methods:

Ten endurance-trained individuals underwent two trials in a repeated-measures experimental design, each involving an initial run to exhaustion at 70% of V˙O2max (Run 1) followed by a 4-h recovery and a subsequent run to exhaustion at 70% of V˙O2max (Run 2). A low-carbohydrate (L-CHO; 0.3 g·kg body mass−1·h−1) or high-carbohydrate (H-CHO; 1.2 g·kg body mass−1·h−1) beverage was ingested at 30-min intervals during recovery. Muscle biopsies were taken upon cessation of Run 1, after recovery, and at exhaustion during Run 2 in L-CHO (F2). In H-CHO, muscle biopsies were obtained after recovery, at the time point coincident with fatigue in L-CHO (F2), and at the point of fatigue during the subsequent exercise bout (F3).

Results:

Run 2 was more prolonged for participants on H-CHO (80 ± 16 min) than for participants on L-CHO (48 ± 11 min; P < 0.001). Muscle glycogen concentrations were higher at the end of recovery for participants on H-CHO (269 ± 84 mmol·kg dry mass−1) than for participants on L-CHO (157 ± 37 mmol·kg dry mass−1; P = 0.001). The rate of muscle glycogen degradation during Run 2 was higher with H-CHO (3.1 ± 1.5 mmol·kg dry mass−1·min−1) than with L-CHO (1.6 ± 1.3 mmol·kg dry mass−1·min−1; P = 0.05). The concentration of muscle glycogen was higher with H-CHO than with L-CHO at F2 (123 ± 28 mmol·kg dry mass−1; P < 0.01), but no differences were observed between treatments at the respective points of exhaustion (78 ± 22 mmol·kg dry mass−1·min−1 for H-CHO vs 72 ± 21 mmol·kg dry mass−1·min−1 for L-CHO).

Conclusion:

Increasing carbohydrate intake during short-term recovery accelerates glycogen repletion in previously exercised muscles and thus improves the capacity for repeated exercise. The availability of skeletal muscle glycogen is therefore an important factor in the restoration of endurance capacity because fatigue during repeated exercise is associated with a critically low absolute muscle glycogen concentration


Impact of Muscle Glycogen Availability on the Capacity for Repeated Exercise in Man. Medicine & Science in Sports & Exercise: January 2016 - Volume 48 - Issue 1 - p 123–131.

http://journals.lww.com/acsm-msse/Abstract/2016/01000/Impact_of_Muscle_Glycogen_Availability_on_the.17.a spx

LunaSpice
2015-12-17, 09:50
Om nästa träningspass sker tidigast efter 24 h så är det väl ingen större skillnad eller hur? Om man tänker att samma mängd kolhydrater intas under en längre tidsperiod än timmarna efter träning.

therunningman
2015-12-17, 10:35
Nej, det är inget som spelar roll för återhämtningen om inte passen ligger extremt tätt och är helt tömmande på glykogen vilket sällan är intressant för som tränar.

Som motionär hade jag nog varit skeptisk till att påskynda återhämtningen. Dels inte sett något behov och dels varit lite rädd för att den skulle kunna ha en (ytterst liten) negativ påverkan på träningen som i mitt fall inte vägs upp av några fördelar som jag har behov av.