Myohemoglobin as an Oxygen‐Store in Man

Åstrand, Irma; Åstrand, Per‐Olof; Christensen, E. Hohwü; Hedman, Rune

doi:10.1111/j.1748-1716.1960.tb01880.x

Cited by 96 publications

(46 citation statements)

References 2 publications

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“…With 10 sec work periods and 20 see (rest) recovery intervals, Astrand, Astrand, Christensen & Hedman (1960b) found an oxygen lag volume of 430 ml. per 10 sec work period.…”

Section: Discussionmentioning

confidence: 93%

Cardiorespiratory and metabolic costs of continuous and intermittent exercise in man

Edwards¹,

Ekelund²,

Harris³

et al. 1973

The Journal of Physiology

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SUMMARY1. Cardiorespiratory and metabolic responses to paired patterns of continuous and intermittent exercise with the same average power output were studied in eight men. Heart rate, ventilation and pulmonary gas exchange were measured during the different patterns of exercise performed on a cycle ergometer. The recovery oxygen volume was measured over 30 min of loadless pedalling. Needle biopsy samples of the vastus lateralis muscle were taken before, during and after completion of the exercise for measurement of muscle metabolites.2. Heart rate, ventilation, oxygen intake, respiratory exchange ratio, and blood lactate concentration were generally higher with intermittent compared with continuous exercise as were the accumulated totals for heart beats, ventilation and oxygen intake. Muscle biopsy samples tended to have higher lactate and lower phosphocreatine contents in intermittent exercise. The lactate concentration in muscle and blood water was the same during loadless pedalling before exercise but was significantly higher in muscle than blood during exercise. This concentration gradient was larger in intermittent than in continuous exercise.3. Work efficiency, calculated from the total oxygen cost of work in excess of a loadless pedalling control, was significantly lower in intermittent exercise. The explanation is thought to be connected with the observation that when the work was performed at a high rate in short bursts a large part of the oxidative recovery took place after the contraction during the rest periods, whereas in the low intensity continuous exercise the oxygen

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“…With 10 sec work periods and 20 see (rest) recovery intervals, Astrand, Astrand, Christensen & Hedman (1960b) found an oxygen lag volume of 430 ml. per 10 sec work period.…”

Section: Discussionmentioning

confidence: 93%

Cardiorespiratory and metabolic costs of continuous and intermittent exercise in man

Edwards¹,

Ekelund²,

Harris³

et al. 1973

The Journal of Physiology

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“…Myoglobin oxygen usage during the work bouts has been estimated to contribute to ϳ44% of the oxygen deficit and has been shown to be resaturated during the rest periods (12). Astrand et al (1) have suggested that myoglobin plays a contributory role as an oxygen store, which supports aerobic metabolism and, presumably, the use of FFAs as a substrate. The source of these FFAs is undetermined, but it has been suggested that intramuscular triacylglycerols (IMTG) stores provide some substrate (32,34).…”

Section: Discussionmentioning

confidence: 99%

Metabolic response of trained and untrained women during high-intensity intermittent cycle exercise

Trapp¹,

Chisholm²,

Boutcher³

2007

American Journal of Physiology-Regulatory, Integrative and Comp

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The metabolic response to two different forms of high-intensity intermittent cycle exercise was investigated in young women. Subjects (8 trained and 8 untrained) performed two bouts of high-intensity intermittent exercise: short sprint (SS) (8-s sprint, 12-s recovery) and long sprint (LS) (24-s sprint, 36-s recovery) for 20 min on two separate occasions. Both workload and oxygen uptake were greater in the trained subjects but were not significantly different for SS and LS. Plasma glycerol concentrations significantly increased during exercise. Lactate concentrations rose over the 20 min and were higher for the trained women. Catecholamine concentration was also higher postexercise compared with preexercise for both groups. Both SS and LS produced similar metabolic response although both lactate and catecholamines were higher after the 24-s sprint. In conclusion, these results show that high-intensity intermittent exercise resulted in significant elevations in catecholamines that appear to be related to increased venous glycerol concentrations. The trained compared with the untrained women tended to show an earlier increase in plasma glycerol concentrations during high-intensity exercise. intermittent exercise; catecholamines; glycerol; lactate STEADY-STATE, MODERATE-INTENSITY aerobic exercise has been recommended for fat loss because the proportion of lipid in the fuel oxidized during low-intensity physical activity is greater than during high-intensity exercise (25). However, it has been shown that individuals engaging in vigorous exercise were leaner than those participating in less intense exercise (31). The ability of high-intensity exercise to cause negative energy balance was also shown by a 15-wk high-intensity intermittent exercise (HIIE) program that resulted in a greater decrease in skinfold thickness relative to energy expenditure compared with 20 wk of endurance exercise (32). The HIIE in this study consisted of short (15-30 s) and long (60 -90 s) sprints separated by recovery periods (1-2 min) allowing the heart rate (HR) to return to 120 -130 beats/min. The energy cost of the HIIE was less than half of that of the endurance program. Thus, despite using half the energy, the impact of the HIIE program, compared with steady-state exercise, on subcutaneous adiposity was significantly greater. However, the effects of HIIE on the components of energy balance were undetermined. Thus how HIIE may cause significant reductions in adiposity is unknown. Possible mechanisms include factors affecting energy intake (24) and postexercise energy expenditure (32).It is feasible that participating in repeated bouts of HIIE could influence postexercise energy expenditure. For example, HIIE is likely to result in a significant elevation of catecholamines (35), which have been shown to elevate postexercise energy expenditure. However, the metabolic response during one bout of HIIE is unclear. For example, when and if free fatty acids (FFAs) are utilized during HIIE is undetermined. Also the catecholamine response and th...

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“…Astrand and Rodahl [5] drew on earlier data [6,7] to present a table of the relative contribution from the aerobic and anaerobic systems during maximal work efforts ranging from 10 seconds up to 120 minutes. Energy release during the shorter more intense exercise periods was estimated from measures of oxygen deficit, using an assumed mechanical efficiency of 22%.…”

Section: Historical Overviewmentioning

confidence: 99%