Effect of two different intense training regimens on skeletal muscle ion transport proteins and fatigue development.
This study examined the effect of two different intense exercise training regimens on skeletal muscle ion transport systems, performance, and metabolic response to exercise. Thirteen subjects performed either sprint training [ST; 6-s sprints (n = 6)], or speed endurance training [SET; 30-s runs approximately 130% Vo(2 max), n = 7]. Training in the SET group provoked higher (P < 0.05) plasma K(+) levels and muscle lactate/H(+) accumulation. Only in the SET group was the amount of the Na(+)/H(+) exchanger isoform 1 (31%) and Na(+)-K(+)-ATPase isoform alpha(2) (68%) elevated (P < 0.05) after training. Both groups had higher (P < 0.05) levels of Na(+)-K(+)-ATPase beta(1)-isoform and monocarboxylate transporter 1 (MCT1), but no change in MCT4 and Na(+)-K(+)-ATPase alpha(1)-isoform. Both groups had greater (P < 0.05) accumulation of lactate during exhaustive exercise and higher (P < 0.05) rates of muscle lactate decrease after exercise. The ST group improved (P < 0.05) sprint performance, whereas the SET group elevated (P < 0.05) performance during exhaustive continuous treadmill running. Improvement in the Yo-Yo intermittent recovery test was larger (P < 0.05) in the SET than ST group (29% vs. 10%). Only the SET group had a decrease (P < 0.05) in fatigue index during a repeated sprint test. In conclusion, turnover of lactate/H(+) and K(+) in muscle during exercise does affect the adaptations of some but not all related muscle ion transport proteins with training. Adaptations with training do have an effect on the metabolic response to exercise and specific improvement in work capacity.
Mohr
Magni
M
Copenhagen Muscle Research Centre, Institute of Exercise and Sport Sciences, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark.
Krustrup
Peter
P
Nielsen
Jens Jung
JJ
Nybo
Lars
L
Rasmussen
Martin Krøyer
MK
Juel
Carsten
C
Bangsbo
Jens
J
D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006003:Glycogen / Q000032:analysis / Q000378:metabolism; D006339:Heart Rate; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood; D008297:Male; D027501:Monocarboxylic Acid Transporters / Q000378:metabolism*; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000502:physiology*; D010725:Phosphocreatine / Q000032:analysis / Q000378:metabolism; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology*; D011188:Potassium / Q000097:blood / Q000378:metabolism; D012420:Running / Q000502:physiology; D012964:Sodium / Q000097:blood / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013997:Time Factors
D027501:Monocarboxylic Acid Transporters; D010725:Phosphocreatine; D019344:Lactic Acid; D006003:Glycogen; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium