Overtraining following intensified training with normal muscle glycogen.
The purpose of this study was to determine if consumption of appropriate amounts of carbohydrate during a period of increased exercise training would protect the athletes from becoming overtrained. Eight male competitive cyclists were monitored and tested during three training periods: a) normal training (moderate intensity, long duration, 7 d, NORM); b) overtraining (high intensity training, 15 d, OVER); and c) recovery (minimal training, 6 d, REC). Throughout the training 160 g of liquid carbohydrate were consumed within the first 2 h after the daily exercise bout. Mean dietary intake (NORM = 13.7 +/- 1.6, OVER = 14.1 +/- 1.0 MJ.d-1) and carbohydrate percent (NORM = 64.0 +/- 2.1, OVER = 67.4 +/- 2.5%) were not different during the different training periods. Similarly, resting muscle glycogen levels were not different (NORM = 530.9 +/- 42.5, OVER = 571.2 +/- 27.5 mumol.g-1 dry weight). Five criteria were used to determine if overtraining occurred in a subject (decreased maximal workload, maximal heart rate, ratio of maximal lactate to rating of perceived exertion (HLa:RPE), and resting plasma cortisol levels, increased affirmative response to a daily questionnaire). All subjects met at least three of the five criteria and thus were classified as overtrained. Therefore, short-term overtraining may occur even when resting muscle glycogen levels are maintained.
Snyder
A C
AC
Department of Physiology, University of Limburg, Maastricht, The Netherlands.
Kuipers
H
H
Cheng
B
B
Servais
R
R
Fransen
E
E
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001823:Body Composition; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004435:Eating; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006003:Glycogen / Q000032:analysis*; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000737:chemistry*
D004040:Dietary Carbohydrates; D006003:Glycogen; D006854:Hydrocortisone