Interval Sprint Training And Endurance Training Effect On The Muscle Fiber Of Skeletal Muscle

Object:We examined the percent of all kinds of musclefibers,the LDH activity and SDH activity on SOL and TA tointerval sprint training and endurance training. Expecting tofinding whether exercise leads muscle fiber transformingMethod: 18 male adult Sprague-Dawley rats were randomlydivided into three groups: control (C, n=6), interval sprinttraining (IST, n=6) and endurance training (ET, n=6).Endurance training by treadmill running (5 day/wk, 30m/min, 7°, 90min/day for 6 weeks). Interval sprint training consistof running six 1-min sprints at 75m/min,15°,interspersed atthe speed of 20m/minwith 1min.The rats in control group andin exercise group were killed by decapitation respectively inquiet status and 12 hours after exercise; the soleus andanterior tibial were removed and tested further. The typeⅠmuscle fibers and typeⅡmuscle fibers were distinguishedthrough ATPase coloration and the isoforms of MHC wereseparated into MHCⅠ,MHCⅡa,MHCⅡb and MHCⅡx throughSDA-PAGE electrophoresis. SDH activity and LDH activity weredetected by SDH kit and LDH kit.Results: (1) The LDH activity of interval sprint traininggroup is higher than that of control group in anterior tibial(p＜0.05);(2) Endurance training can increase the SDH activityobviously in soleus (p＜0.05);(3) Compared to C group and IST group, the percent ofMHCⅠand MHCⅡa increased obviously, and the percent of MHC Ⅱb decreased obviously in soleus of SD rat.(4) Compared to C group, the percent of MHCⅡa increasedobviously, the percent of MHCⅡb decreased obviously in ATof SD rat.(5) Compared to ISTgroup, the percent of MHCⅡx increasedobviously in AT of SD rat.Conclusion:(1) Endurance training and interval sprint training canlead to MHC subfibers transforming,but different in transformmodel: endurance training leading MHCⅡb and MHCⅡa transformto MHCⅠand interval sprint training leading MHCⅡb andMHCⅡx transform to MHCⅡa;(2) Endurance training leads typeⅡfibers isoforming totypeⅠ, but interval sprint training can not leads typeⅠfibersisoforming to typeⅡ;(3) Both fast fiber and slow fiber have the potentialityto increase the oxidbillity;(4) The interval sprint training of a certain intensitycan improve the LDH ativity, but endurance training can notimprove the LDH ativity.