Human muscle metabolism during intermittent maximal exercise.

نویسندگان

  • G C Gaitanos
  • C Williams
  • L H Boobis
  • S Brooks
چکیده

Eight male subjects volunteered to take part in this study. The exercise protocol consisted of ten 6-s maximal sprints with 30 s of recovery between each sprint on a cycle ergometer. Needle biopsy samples were taken from the vastus lateralis muscle before and after the first sprint and 10 s before and immediately after the tenth sprint. The energy required to sustain the high mean power output (MPO) that was generated over the first 6-s sprint (870.0 +/- 159.2 W) was provided by an equal contribution from phosphocreatine (PCr) degradation and anaerobic glycolysis. Indeed, within the first 6-s bout of maximal exercise PCr concentration had fallen by 57% and muscle lactate concentration had increased to 28.6 mmol/kg dry wt, confirming significant glycolytic activity. However, in the tenth sprint there was no change in muscle lactate concentration even though MPO was reduced only to 73% of that generated in the first sprint. This reduced glycogenolysis occurred despite the high plasma epinephrine concentration of 5.1 +/- 1.5 nmol/l after sprint 9. In face of a considerable reduction in the contribution of anaerobic glycogenolysis to ATP production, it was suggested that, during the last sprint, power output was supported by energy that was mainly derived from PCr degradation and an increased aerobic metabolism.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Comparison of the Effect of 8 Weeks of Continuous, Intermittent Training on Maximum Oxygen Consumption, Muscle Endurance and General Health of Overweight Seventh Grade Male Students

Background and Objectives: Interval training, in various forms, is one of the most effective tools today to improve cardiorespiratory and metabolic function and in turn improve physical function. The aim of the present study was to compare the effect of 8 weeks of continuous, intermittent exercise on maximum oxygen consumption, muscle endurance and general health of overweight seventh grade mal...

متن کامل

Myofibrillar and collagen protein synthesis in human skeletal muscle in young men after maximal shortening and lengthening contractions.

We aimed to determine whether there were differences in the extent and time course of skeletal muscle myofibrillar protein synthesis (MPS) and muscle collagen protein synthesis (CPS) in human skeletal muscle in an 8.5-h period after bouts of maximal muscle shortening (SC; average peak torque = 225 +/- 7 N.m, means +/- SE) or lengthening contractions (LC; average peak torque = 299 +/- 18 N.m) wi...

متن کامل

Prolonged Intermittent Running Induces Inspiratory-Muscle Fatigue in Female Runners

Inspiratory-muscle fatigue (IMF) may occur after long-duration or continuous short-duration exercise and may limit exercise performance. Daily athletics training is often intermittent, but it is unclear if intermittent running induces IMF. We investigated IMF after a maximal anaerobic running test (MART) and maximal intermittent graded exercise test. Nine female middle-distance (400 or 800 m) r...

متن کامل

High-intensity intermittent exercise: methodological and physiological aspects.

High-intensity intermittent exercise (HIIE) has been applied in competitive sports for more than 100 years. In the last decades, interval studies revealed a multitude of beneficial effects in various subjects despite a large variety of exercise prescriptions. Therefore, one could assume that an accurate prescription of HIIE is not relevant. However, the manipulation of HIIE variables (peak work...

متن کامل

Activation by exercise of human skeletal muscle pyruvate dehydrogenase in vivo.

1. The activity of pyruvate dehydrogenase in its active and inactive forms was measured in biopsy samples obtained from the vastus lateralis muscle of healthy subjects before and after exercise. 2. At rest, 40 +/- 4% (mean +/- SEM) of the enzyme was in the active form. 3. After progressive aerobic exercise to exhaustion (n = 5), 88 +/- 2.3% was in the active form. 4. After intermittent supramax...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of applied physiology

دوره 75 2  شماره 

صفحات  -

تاریخ انتشار 1993