Glycogen, Glycolytic Intermediates and High-Energy Phosphates Determined in Biopsy Samples of Musculus Quadriceps Femoris of Man at Rest. Methods and Variance of Values

Limited data exist on the efficacy of low-load blood flow-restricted strength training (BFR), as compared directly to heavy-load strength training (HST). Here, we show that 12 wk of twice-a-week unilateral BFR [30% of one repetition maximum (1RM) to exhaustion] and HST (6-10RM) of knee extensors provide similar increases in 1RM knee extension and cross-sectional area of distal parts of musculus quadriceps femoris in nine untrained women (age 22 ± 1 yr). The two protocols resulted in similar acute increases in serum levels of human growth hormone. On the cellular level, 12 wk of BFR and HST resulted in similar shifts in muscle fiber composition in musculus vastus lateralis, evident as increased MyHC2A proportions and decreased MyHC2X proportions. They also resulted in similar changes of the expression of 29 genes involved in skeletal muscle function, measured both in a rested state following 12 wk of training and subsequent to singular training sessions. Training had no effect on myonuclei proportions. Of particular interest, 1) gross adaptations to BFR and HST were greater in individuals with higher proportions of type 2 fibers, 2) both BFR and HST resulted in approximately four-fold increases in the expression of the novel exercise-responsive gene Syndecan-4, and 3) BFR provided lesser hypertrophy than HST in the proximal half of musculus quadriceps femoris and also in CSApeak, potentially being a consequence of pressure from the tourniquet utilized to achieve blood flow restriction. In conclusion, BFR and HST of knee extensors resulted in similar adaptations in functional, physiological, and cell biological parameters in untrained women.

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Phosphagen and lactate contents of m. quadriceps femoris of man after exercise

Journal of Applied Physiology ◽

10.1152/jappl.1977.43.5.852 ◽

1977 ◽

Vol 43 (5) ◽

pp. 852-857 ◽

Cited By ~ 57

Author(s):

R. C. Harris ◽

K. Sahlin ◽

E. Hultman

Keyword(s):

General Pattern ◽

Isometric Exercise ◽

High Energy ◽

Quadriceps Femoris ◽

High Energy Phosphates ◽

Muscle Lactate ◽

Steady State Condition ◽

Muscle Ph ◽

Determining Factors ◽

Muscle Biopsies

Muscle biopsies were taken from the m. quadriceps femoris of man immediately after termination of dynamic and isometric exercise. These were analyzed for adenosine triphosphate (ATP), adenosine 5′-diphosphate (ADP), adenosine 5′-phosphate (AMP), phosphorylcreatine (PC), creatine, pyruvate and lactate. Regardless of type, intensity, and duration of the preceding exercise, a general pattern of the relation between high-energy phosphates and lactate content could be observed. PG showed a nonlinear relationship to the muscle lactate content. The ratio of ATP to ADP appeared to decrease linearly when lactate content increased. The relationships are believed to be the consequence of a steady-state condition where muscle pH is one of the major determining factors.

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Exercise hyperthermia as a factor limiting physical performance: temperature effect on muscle metabolism

Journal of Applied Physiology ◽

10.1152/jappl.1985.59.3.766 ◽

1985 ◽

Vol 59 (3) ◽

pp. 766-773 ◽

Cited By ~ 86

Author(s):

S. Kozlowski ◽

Z. Brzezinska ◽

B. Kruk ◽

H. Kaciuba-Uscilko ◽

J. E. Greenleaf ◽

...

Keyword(s):

Adverse Effect ◽

Muscle Metabolism ◽

Creatine Phosphate ◽

High Energy ◽

High Energy Phosphates ◽

Glycogen Depletion ◽

Heavy Exercise ◽

High Energy Phosphate ◽

Glycolytic Intermediates ◽

Temperature Equilibrium

The muscle contents of high-energy phosphates and their derivatives [ATP, ADP, AMP, creatine phosphate (CrP), and creatine], glycogen, some glycolytic intermediates, pyruvate, and lactate were compared in 11 dogs performing prolonged heavy exercise until exhaustion (at ambient temperature 20.0 +/- 1.0 degrees C) without and with trunk cooling using ice packs. Without cooling, dogs were able to run for 57 +/- 8 min, and their rectal (Tre) and muscle (Tm) temperatures increased to 41.8 +/- 0.2 and 43.0 +/- 0.2 degrees C, respectively. Compared with noncooling, duration of exercise with cooling was longer by approximately 45% while Tre and Tm at the time corresponding to the end of exercise without cooling were lower by 1.1 +/- 0.2 and 1.2 +/- 0.2 degrees C, respectively. The muscle contents of high-energy phosphates (ATP + CrP) decreased less, the rate of glycogen depletion was lower, and the increases in the contents of AMP, pyruvate, and lactate as well as in the muscle-to-blood lactate ratio were smaller. The muscle content of lactate was positively correlated with Tm. The data indicate that with higher body temperature equilibrium between high-energy phosphate breakdown and resynthesis was shifted to the lower values of ATP and CrP and glycolysis was accelerated. The results suggest that hyperthermia developing during prolonged muscular work exerts an adverse effect on muscle metabolism that may be relevant to limitation of endurance.

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