Abstract
The degree to which the y-intercept (Y-int) of the linear regression of maximal work output on exercise duration represented anaerobic capacity was determined in ten well-trained male cyclists [peak oxygen uptake (\(\dot V{\text{O}}_{{\text{2peak}}} \) = 69.8 (SD 4.2) ml · kg −1 · min −1). Each cyclist performed three exhausting cycle sessions on separate occasions; the mean exercise durations were 312, 243 and 141 s for the low (approximately 104% \(\dot V{\text{O}}_{{\text{2peak}}} \), medium (approximately 108% \(\dot V{\text{O}}_{{\text{2peak}}} \) and high (approximately 113% \(\dot V{\text{O}}_{{\text{2peak}}} \) intensities respectively, and Y-int (kilojoules; joules per kilogram was derived from the regression of work output on exercise duration. The muscle anaerobic adenosine 5′-triphosphate (ATP) yield (ΣATP) and anaerobic capacity (AC) were estimated from changes in metabolites in the vastus lateralis muscle and blood lactate concentration during the high intensity cycling session. The activities of glycogen phosphorylase, phosphofructokinase and citrate synthase, as well as muscle buffer value (in vitro β) were also determined. The Y-int (kilojoules) was positively correlated (P≤0.05) with AC (r=0.73), ΣATP (r=0.70) and in vitro β (r=0.71); similar correlations (P≤0.05) were observed for Y-int (joules per kilogram). The Y-int was not correlated (P>0.05) with any enzyme activity. When the Y-int was transformed into oxygen equivalents [litres of oxygen equivalent (1 O2 Eq)] it was, on average, 0.92 1 O2 Eq lower than AC (P≤0.05); however, an alternative method of establishing the work-duration regression yielded a mean Y-int which was only 0.19 1 O2 Eq less than AC (P≥0.05). These findings support the validity of Y-int as a work estimate of anaerobic capacity in well-trained cyclists.
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References
Åstrand P-O, Rodahl K (1977) Textbook of work physiology. Physiological bases of exercise. McGraw-Hill, New York, p 134
Åstrand P-O, Hultman E, Juhlin-Dannfelt A, Reynolds G (1986) Disposal of lactate during and after strenuous exercise in humans. J Appl Physiol 61:338–343
Castellini MA, Somero GN (1981) Buffering capacity of vertebrate muscle: correlations with potentials for anaerobic function. J Comp Physiol 143:191–198
Coyle EF, Feltner ME, Kautz SA, Hamilton MT, Montain SJ, Baylor AM, Abraham LD, Petrek GW (1991) Physiological and biomechanical factors associated with elite endurance cycling performance. Med Sci Sports Exerc 23:93–107
Elder GCB, Bradbury K, Roberts R (1982) Variability of fiber type distributions within human muscles. J Appl Physiol 53:1473–1480
Gaesser GA, Wilson LA (1988) Effects of continuous and interval training on the parameters of the power-endurance time relationship for high-intensity exercise. Int J Sports Med 9:417–421
Green HJ, Jones S, Ball-Burnett ME, Smith D, Liversey J, Farrance BW (1991) Early muscular and metabolic adaptations to prolonged exercise training in humans. J Appl Physiol 70:2032–2038
Green S, Dawson BT (1993) Measurement of anaerobic capacities in humans: definitions, limitations and unsolved problems. Sports Med 15:312–327
Harris RC, Hultman E, Nordesjo L-O (1974) Glycogen, glycolytic intermediates and high energy phosphates determined in biopsy samples of m. quadriceps femoris of man at rest. Methods and variance of values. Scand J Clin Lab Invest 33:109–120
Harris RC, Marlin DJ, Dunnett M, Snow DH, Hultman E (1990) Muscle buffering capacity and dipeptide content in the thoroughbred horse, greyhound dog and man. Comp Biochem Physiol 97A:249–251
Jenkins DG, Quigley BM (1991) The γ-intercept of the critical power function as a measure of anaerobic work capacity. Ergonomics 34:13–22
Jenkins DG, Quigley BM (1993) The influence of high-intensity exercise training on the Wlim- Tlim relationship. Med Sci Sports Exerc 25:275–282
Lowry OH, Passoneau JV (1972) A flexible system of enzymatic analysis. Academic Press, New York
Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275
McLellan T, Cheung KS (1992) A comparative evaluation of the individual anaerobic threshold and the critical power. Med Sci Sports Exerc 24:543–550
Medbø JI, Tabata I (1989) Relative importance of aerobic and anaerobic energy release during short-lasting exhausting bicycle exercise. J Appl Physiol 67:1881–1886
Medbø JI, Mohn AC, Tabata I, Bahr R, Vaage O, Sejersted OH (1988) Anaerobic capacity determined by maximal accumulated O2 deficit. J Appl Physiol 64:50–60
Meyer RA, Terjung RL (1979) Differences in ammonia and adenylate metabolism in contracting fast and slow muscle. Am J Physiol 55:218–224
Monod H, Scherrer J (1965) The work capacity of a synergic muscular group. Ergonomics 8:329–338
Peronnet F, Massicotte D (1991) Table of nonprotein respiratory quotient: an update. Can J Sports Sci 16:23–29
Poole DC, Ward SA, Whipp BJ (1990) The effects of training on the metabolic and respiratory profile of high-intensity cycle ergometer exercise. Eur J Appl Physiol 59:421–429
Sahlin K, Palmskog G, Hultman E (1978) Adenine nucleotide and IMP contents of the quadriceps muscle in man after exercise. Pflügers Arch 374:193–198
Saltin B (1990) Anaerobic capacity: past, present, and prospective. In: Taylor AW, Gollnick PD, Green HJ, Ianuzzo CD, Noble EG, Metivier G, Sutton JR (eds) Biochemistry of exercise VII, International Series on Sport Sciences, 21. Human Kinetics. Champaign, Ill., pp 387–412
Scherrer J, Samson M, Paleologue A (1954) Etudé du travail musculaire et de la fatigue. Données ergométriques obtenues chez l'homme. J Physiol (Paris) 46:887–916
Sharp RL, Costill DL, Fink WJ, King DS (1986) Effects of eight weeks of bicycle ergometer sprint training on human muscle buffer capacity. Int J Sports Med 7:13–17
Sjogaard G (1984) Muscle morphology and metabolic potential in elite road cyclists during a season. Int J Sports Med 5:250–254
Spriet LL, Soderlund K, Thomson JA, Hultman E (1986) pH measurement in human skeletal muscle samples: effect of phosphagen hydrolysis. J Appl Physiol 61:1949–1954
Thomas JR, Nelson JK (1985) Introduction to research in health, physical education, recreation, and dance. Human Kinetics, Champaign, Ill., pp 254–257
Vandewalle H, Kapitaniak B, Grün S, Raveneau S, Monod H (1989) Comparison between a 30-s all-out test and a timework test on a cycle ergometer. Eur J Appl Physiol 58:375–381
Whipp BJ, Huntsman DJ, Storer TW, Lamara N, Wasserman K (1982) A constant which determines the duration of tolerance to high-intensity work. Fed Proc 41:1591
Withers RT, Sherman WM, Clark DG, Esselbach PC, Nolan SR, Mackay MH, Brinkman M (1991) Muscle metabolism during 30, 60 and 90 s of maximal cycling on an air-braked egometer. Eur J Appl Physiol 63:354–362
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Green, S., Dawson, B.T., Goodman, C. et al. Y-intercept of the maximal work-duration relationship and anaerobic capacity in cyclists. Eur J Appl Physiol 69, 550–556 (1994). https://doi.org/10.1007/BF00239874
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DOI: https://doi.org/10.1007/BF00239874