Intermittent Muscular Work

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

doi:10.1111/j.1748-1716.1960.tb01879.x

Cited by 201 publications

(140 citation statements)

References 3 publications

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“…Studies in healthy people have shown that repeated maximal-intensity exercise bouts, allowing corresponding short rest intervals between bouts, can be tolerated for an extensive period [7] and yield similar physiological benefits to extended high-intensity continuous exercise [22,23]. Furthermore, as shown in healthy individuals [24], the metabolic response to interval exercise is very similar to that to continuous exercise at half the WR, suggesting that the relief intervals between bouts of hard work in IT bear special importance with regard to the successful application of maximal-intensity training.…”

Section: Discussionmentioning

confidence: 99%

“…repeated periods of maximal or high-intensity exercise alternating with corresponding short intervals of rest. Early studies in healthy subjects showed that more work can be performed before exhaustion sets in by exercising with intervals than when the same total amount of work is performed continuously [7][8][9]. GOSSELINK et al [10] and COPPOOLSE et al [11] examined the effects of IT on measures of exercise tolerance and compared its efficacy to that of continuous exercise in COPD patients.…”

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confidence: 99%

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Interval training as an alternative modality to continuous exercise in patients with COPD

Vogiatzis¹,

Nanas²,

Roussos³

2002

Eur Respir J

217

196

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Understanding of what constitutes a training load adequate to induce training effects in patients with chronic obstructive pulmonary disease (COPD) is still evolving. The present study investigated whether interval training (IT) is effective in terms of inducing measurable improvements in physiological response and compared its effects on exercise tolerance (ET) and quality of life to those of continuous training (CT).Thirty-six COPD patients, with a forced expiratory volume in one second of 45±4% of the predicted value (mean±sem), were randomly assigned to CT (exercise at 50% of baseline peak work-rate) or IT (work for 30 s at 100% of peak work-rate alternating with 30‐s rest intervals) groups that cycled 40 min·day−1and 2 days·week−1for 12 weeks.After training, both groups showed significantly improved ET (IT, 57±6 to 71±8 W; CT, 57±5 to 70±6 W) and total quality-of-life score of the Chronic Respiratory Disease Questionnaire (IT, 77±3 to 88±2; CT, 78±3 to 93±2). At identical levels of exercise, minute ventilation was significantly reduced (IT, 35.8±2.5 to 31.7±2.5 L·min−1; CT, 36.4±2.7 to 32.5±2.7 L·min−1). The magnitude of improvement in these variables was not significantly different among groups.The present data expand on the principles of exercise prescription for chronic obstructive pulmonary disease patients by demonstrating that interval training elicits substantial training effects, which are similar in magnitude to those produced by continuous training at half the exercise intensity but double the exercise time.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Interval training as an alternative modality to continuous exercise in patients with COPD

Vogiatzis¹,

Nanas²,

Roussos³

2002

Eur Respir J

217

196

View full text Add to dashboard Cite

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“…This is important because longer periods of hyperoxia are accompanied by reductions in resting MSNA and BP as a result of chemoreflex inhibition (8,26,38). Moreover, isometric exercise produces a greater increase in BL than rhythmic exercise (5,36).…”

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confidence: 99%

Hyperoxia enhances metaboreflex sensitivity during static exercise in humans

Houssière

Najem²,

Cuylits³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

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Houssière, Anne, Boutaina Najem, Nicolas Cuylits, Sophie Cuypers, Robert Naeije, and Philippe van de Borne. Hyperoxia enhances metaboreflex sensitivity during static exercise in humans. Am J Physiol Heart Circ Physiol 291: H210 -H215, 2006; doi:10.1152/ajpheart.01168.2005.-Peripheral chemoreflex inhibition with hyperoxia decreases sympathetic nerve traffic to muscle circulation [muscle sympathetic nerve activity (MSNA)]. Hyperoxia also decreases lactate production during exercise. However, hyperoxia markedly increases the activation of sensory endings in skeletal muscle in animal studies. We tested the hypothesis that hyperoxia increases the MSNA and mean blood pressure (MBP) responses to isometric exercise. The effects of breathing 21% and 100% oxygen at rest and during isometric handgrip at 30% of maximal voluntary contraction on MSNA, heart rate (HR), MBP, blood lactate (BL), and arterial O 2 saturation (SaO 2 ) were determined in 12 healthy men. The isometric handgrips were followed by 3 min of postexercise circulatory arrest (PE-CA) to allow metaboreflex activation in the absence of other reflex mechanisms. Hyperoxia lowered resting MSNA, HR, MBP, and BL but increased Sa O 2 compared with normoxia (all P Ͻ 0.05). MSNA and MBP increased more when exercise was performed in hyperoxia than in normoxia (MSNA: hyperoxic exercise, 255 Ϯ 100% vs. normoxic exercise, 211 Ϯ 80%, P ϭ 0.04; and MBP: hyperoxic exercise, 33 Ϯ 9 mmHg vs. normoxic exercise, 26 Ϯ 10 mmHg, P ϭ 0.03). During PE-CA, MSNA and MBP remained elevated (both P Ͻ 0.05) and to a larger extent during hyperoxia than normoxia (P Ͻ 0.05). Hyperoxia enhances the sympathetic and blood pressure (BP) reactivity to metaboreflex activation. This is due to an increase in metaboreflex sensitivity by hyperoxia that overrules the sympathoinhibitory and BP lowering effects of chemoreflex inhibition. This occurs despite a reduced lactic acid production.handgrip; muscle sympathetic nerve activity; metaboreceptors; chemoreceptors MUSCLE METABORECEPTORS regulate sympathetic activation during exercise (19,25). This reflex is activated by metabolites released from exercising skeletal muscle. Several substances, such as lactic acid, phosphate, K ϩ , H ϩ , adenosine, prostaglandins, and bradykinin, are now identified as stimulators of this pressor reflex (35,37,40).These metabolites stimulate group III and IV chemosensitive afferents in the working muscles (32). These afferent fibers can also be activated by injection of lactic acid or a hyperosmolar solution of potassium chloride, and their activity is modulated by endogenous nitric oxide in resting and contracting muscle (3,6,11,13,16). This activation in both nonexercising and exercising limbs (32) provokes a rise in cardiac output and vasoconstriction of the nonischemic vascular beds. As a result, blood pressure (BP) and perfusion pressure increase and correct blood flow deficits during exercise (32,35,40,43).There are several reasons to believe that hyperoxia may affect sympathetic regulation during exercise.First, hyp...

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“…ndurance training effects of short-duration intermittent runs have been reported in athletes (3,9,23) with improved maximal oxygen consumption ( _ Vo 2 max) and delayed fatigue compared to continuous running methods (10,15). Balsom et al (5,8) have shown that short-duration intermittent training allows limited lactate production and increased creatine phosphate metabolism during intermittent exercise.…”

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confidence: 99%