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At least 361 records · Page 20Linked to original sources
PubMed2005

B-chronic lymphocytic leukemia cells exert an in vitro cytotoxicity mediated by tumor necrosis factor alpha.

Tumor necrosis factor alpha (TNFalpha) is constitutively produced by B-chronic lymphocytic leukemia (B-CLL) cells and may act as an autocrine factor for their growth and survival. However, very few data are available on the possible cytotoxic effect of TNFalpha produced by B-CLL cells. This study investigated whether B-CLL cells exert in vitro cytotoxicity by TNFalpha and if so, whether this cytotoxicity can be modulated by cytokines. In 8 of 12 patients (66.6%), B-CLL cells in vitro constitutively produced TNFalpha and exerted a TNFalpha-mediated cytotoxicity, evaluated in an 18-h 51Cr release assay, against the TNFalpha-sensitive Jurkat, U937 and K562 cell lines but not against the TNFalpha-resistant Raji cell line. Involvement of TNFalpha in B-CLL cell cytotoxicity is demonstrated by the fact that anti-TNFalpha antibodies strongly inhibited it and supernatants of cytotoxic cultures contained TNFalpha and mediated a completely TNFalpha-dependent cytotoxicity. When the cytotoxic B-CLL cells were stimulated with interleukin (IL)-2 plus IL-12, there was increased TNFalpha mRNA expression, TNFalpha production and TNFalpha-mediated cytotoxicity. All eight patients with cytotoxic leukemic cells had progressive disease and six of these also expressed high levels of ZAP-70 protein. In the other four patients (33.3%), B-CLL cells did not produce TNFalpha in vitro and were not cytotoxic, either spontaneously or after IL-2 plus IL-12 stimulation. Of these four patients, three had stable disease and one had progressive disease. The patient with progressive disease and one of the three with stable disease expressed low levels of ZAP-70 protein. We conclude that a group of B-CLL patients with progressive disease have leukemic B cells able to exert in vitro a TNFalpha-mediated cytotoxicity, which is modulated by cytokines.

ADP-ribosyl Cyclase↗
PubMed1983

Variable threshold exertional angina in patients with transient vasospastic myocardial ischemia. Repeat exercise test results and therapeutic implications.

Thirty-five of 70 patients with vasospastic angina at rest complained of chest pain during exercise or during usual daily activity. In 22, the angina threshold was described as variable during exercise: that is, the amount of exertion that induced angina was not always the same. In 12 patients with variable threshold exertional angina, 3 exercise tests performed in the morning on different days yielded different results, because chest pain and ischemic electrocardiographic changes occurred at different work loads with a wide range in heart rate-systolic pressure product. Two patients, in whom great cardiac vein flow was measured during exercise before and after taking nifedipine, tolerated heavier work loads after receiving the drug, with a more marked increase in flow during exercise. It is concluded that variable threshold exertional angina can be objectively demonstrated by repeat exercise tests in patients with vasospastic angina. Variability of the angina threshold may be due to a functional mechanism that causes myocardial ischemia in addition to the increased myocardial metabolic requirements provoked by exercise. Because in such patients fluctuations in coronary arterial tone play an important role in determining the response to exercise, calcium antagonistic drugs, which lower coronary tone and prevent the occurrence of coronary spasm, are effective in increasing exercise capacity.

Adult↗
PubMed2003

Quercetin exerts multiple inhibitory effects on vascular smooth muscle cells: role of ERK1/2, cell-cycle regulation, and matrix metalloproteinase-9.

The French paradox has been attributed to the antioxidant properties of flavonoids present in the red wine. Quercetin, a bioflanoid present in the human diet, is known to inhibit angiotensin II-induced hypertrophy and serum-induced smooth muscle cell proliferation. However, it is not known whether quercetin exerts similar cardioprotective effects in cells treated with TNF-alpha. In this study, we investigated whether quercetin exerts the multiple suppressive effects on cytokine TNF-alpha-induced human aortic smooth muscle cells (HASMC). Treatment of quercetin showed potent inhibitory effects on the DNA synthesis of cultured HASMC in the presence of TNF-alpha. These inhibitory effects were associated with reduced extracellular signal-regulated kinase (ERK)1/2 activity and G1 cell-cycle arrest. Treatment of quercetin, which induced a cell-cycle block in G1-phase, induced down-regulation of cyclins and CDKs and up-regulation of the CDK inhibitor p21 expression, whereas up-regulation of p27 or p53 by quercetin was not observed. Because anti-atherogenic effects need not be limited to antiproliferation, we decided to examine whether quercetin exerted inhibitory effects on matrix metalloproteinase-9 (MMP-9) activity in TNF-alpha-induced HASMC. Quercetin inhibited TNF-alpha-induced MMP-9 secretion on HASMC in a dose-dependent manner. This inhibition was characterized by down-regulation of MMP-9, which was transcriptionally regulated at NF-kappaB site and activation protein-1 (AP-1) site in the MMP-9 promoter. These findings indicate the efficacy of quercetin in inhibiting cell proliferation, G1- to S-phase cell-cycle progress, and MMP-9 expression through the transcription factors NF-kappaB and AP-1 on TNF-alpha-induced HASMC.

Cell Cycle↗
PubMed2002

Relative contribution of trunk muscles to the stability of the lumbar spine during isometric exertions.

OBJECTIVE: To compare the relative contribution of various trunk muscles to the stability of the lumbar spine. DESIGN: Quantification of spine stability with a biomechanical model. BACKGROUND: Modern low back rehabilitation techniques focus on muscles that stabilize the lumbar spine. However, the relative contribution of various trunk muscles to spine stability is currently unknown. METHODS: Eight male subjects performed isometric exertions in trunk flexion, extension, lateral bending, and axial rotation, and isometric exertions under vertical trunk loading and in a lifting hold. Each isometric trial was repeated three times at 20%, 40%, and 60% of the maximum trunk flexion force or with a load of 0%, 20%, 40%, and 60% of body weight for the latter two exertions. Surface EMG data from 12 major trunk muscles were used in the biomechanical model to estimate stability of the lumbar spine. A simulation of each trial was performed repeatedly with one of the 10 major trunk muscle groups removed from the model. RESULTS: Relative contribution of each muscle to spine stability was significantly affected by the combination of loading magnitude and direction (3-way interaction). None of the removed muscles reduced spine stability by more than 30%. CONCLUSIONS: A single muscle cannot be identified as the most important for the stability of the lumbar spine. Rather, spine stability depends on the relative activation of all trunk muscles and other loading variables. RELEVANCE: This study will improve our understanding of individual trunk muscles' contribution to overall stability of the lumbar spine.

Adult↗
PubMed1997

Forearm extensor and flexor muscle exertion during simulated gripping work -- an electromyographic study.

OBJECTIVE: To study forearm muscular exertion during intermittent gripping work at three different regimes resembling vocational work. DESIGN: An electromyographic laboratory study of forearm fatigue during intermittent gripping work at 25% MVC with 10/10, 20/10 and 30/10 s of work/rest was performed. BACKGROUND: Data from the literature indicate that forearm flexors as well as extensors are activated during gripping. However, no systematic quantitative assessment of the muscular exertion has been made hitherto. METHODS: Nine female subjects participated. EMG was detected from five forearm muscles, three extensors and two flexors. Zero crossing rate alterations were used as an index of fatigue. RESULTS: The results show significant (P < 0.05) fatigue signs in at least two of the extensor muscles at all regimes while significant signs of fatigue was seen only at the 30/10 regime for the flexor muscles. CONCLUSIONS: Fatigue effects are generally larger on the extensor side. None of the studied regimes is acceptable from EMG fatigue point of view. RELEVANCE: The muscular fatigue of the forearm extensors in relation to the flexors during gripping work has not been systematically assessed before. Forearm fatigue distribution is probably of great importance for the understanding of forearm disorders related to muscular exertion.

Journal Article↗
PubMed1999

Variation in spinal load and trunk dynamics during repeated lifting exertions.

OBJECTIVES: To quantify the variability in lifting motions, trunk moments, and spinal loads associated with repeated lifting exertions and to identify workplace factors that influence the biomechanical variability. DESIGN: Measurement of trunk dynamics, moments and muscle activities were used as inputs into EMG assisted model of spinal loading. BACKGROUND: Traditional biomechanical models assume repeated performance of a lifting task produces little variability in spinal load because the assessments overlook variability in lifting dynamics and muscle coactivity. METHODS: Five experienced and seven inexperienced manual materials handlers performed 10 repeated lifts at each combination of load weight, task asymmetry and lifting velocity. RESULTS: Box weight, task asymmetry and job experience influenced the magnitude and variability of spinal load during repeated lifting exertions. Surprisingly, experienced subjects demonstrated significantly greater spinal loads and within-subject variability in spinal load than inexperienced subjects. Trial-to-trial variability accounted for 14% of the total variation in compression overall and 32% in lateral shear load. Although the mean spinal load was safely below the NIOSH recommended limit; due to variability about the mean, more than 20% of the lifts exceeded the recommended limit. CONCLUSION: Spinal load changed markedly from one exertion to the next despite identical task requirements. Trial-to-trial variability in kinematics, kinetics, and spinal load were influenced by workplace factors, and may play a role in the risk of low-back pain. RELEVANCE: Ergonomic assessments considering only the mean value of spinal load overlook the fact that a large fraction of the lifts may exceed recommended levels.

Adult↗
PubMed2003

[Endoscopic aponeurotomy for chronic exertional compartmental syndrome of the forearm: report of 41 cases].

INTRODUCTION: Chronic exertional compartment syndrome of the forearm is probably underdiagnosed as a cause of forearm pain in the sportsman. Its pathological basis is a critical elevation of extracellular pressure. The clinical diagnosis is confirmed by measurements of intracompartmental pressures. We described a reliable original method of endoscopically assisted superficial fasciotomy for treating chronic exertional compartment syndrome of the forearm. The goal of the study is the physiological and clinical validation of this technique. STUDY DESIGN: Retrospective cohort study after the anatomical assessment of the feasibility of our endoscopically assisted fasciotomy. METHODS: Review of 41 forearm decompressions in 25 patients (23 sportsmen and 2 musicians). Follow-up of 6 months to 9 years. RESULTS: Eighty-eight percent reported an excellent or good outcome with significant reduction of pain during exercise. Three patients noted the return of their compartment syndrome and this was confirmed by new measurements of intramuscular pressure. Two of them underwent fasciectomy with excision of a hypertrophic scar of the superficial aponevrosis to good effect. COMPLICATIONS: Two hematomas and 2 lateral epicondylitis with no adverse effect on the final result. DISCUSSION: Endoscopically assisted fasciotomy is a reliable technique for reducing pain in chronic compartment exertional syndromes. It allows the large majority of patients to return to sports. It is our first choice indication in young sportsmen for syndromes of the forearm (anterior and/or posterior compartment). The limit of the technique is the current knowledge of collagenic tissues pathology as a cause of recurrence with hypertrophic aponevrotic scars.

Adolescent↗
PubMed1997

Cyclic AMP negatively controls c-myc transcription and G1 cell cycle progression in p210 BCR-ABL transformed cells: inhibitory activity exerted through cyclin D1 and cdk4.

Raised intracellular cyclic AMP (cAMP) has been demonstrated to exert an antiproliferative effect in myeloid cells. How the antiproliferative activity of cAMP is exerted in p210 BCR-ABL transformed myeloid cells was the subject of this investigation. It was hypothesized that cyclin dependent kinase 4, cdk4, might be a critical target enzyme to affect the related events of c-myc transcription and progression through G1 phase of the cell cycle within cells transformed by p210 BCR-ABL, and further, that cdk4 might be downregulated by cAMP to inhibit proliferation. In order to investigate the regulatory role of cdk4, synchronized cells were studied. In p210 BCR-ABL transformed cells transiting early G1 phase, treatment with a cAMP analogue led to inhibition of cyclin D1 synthesis, and marked reduction of cdk4 kinase activity. Within cells in which cdk4 was inhibited by cAMP, there was augmented interaction of E2F1 with the retinoblastoma protein, pRb in a nuclear matrix-associated cell fraction. As a result of E2F1 sequestration, raised intracellular cAMP was found to inhibit c-myc transcription in p210 BCR-ABL transformed myeloid cells synchronously transiting the early G1 phase of the cell cycle. A target of this transcriptional suppression exerted by cAMP was the E2F site of the c-myc P2 promoter. On the other hand, cyclin D1 content was not reduced by cAMP in these cells when it was applied at a later cell cycle stage at the interface between G1 and S. Corresponding to lack of cyclin D1 inhibition in these later G1-to-S phase cells, cdk4 activity was only modestly suppressed, and c-myc mRNA expression was also inhibited to a lesser degree. These studies show that Rb interaction with E2F1 is regulated by cdk4 and cyclin D1 within p210 BCR-ABL transformed leukemia cells in early G1 phase of the cell cycle. In this context, both cyclin D1 and cdk4 are subject to the level of intracellular cAMP. This interaction between Rb and E2F1, which is subject to the level of cAMP, is critical to transcriptional control of c-myc. Further, pRb regulation of E2F activity affects cellular potential for G1-S phase transition in p210 BCR-ABL transformed myeloid cells, in part, via its effect on c-myc transcription.

Animals↗
PubMed1983

Insulin exerts actions through a distinct species of guanine nucleotide regulatory protein: inhibition of adenylate cyclase.

Insulin failed to exert an effect on the basal and glucagon- and guanosine 5'-[beta, gamma-imido]-triphosphate-stimulated adenylate cyclase activities of hepatocyte membranes. In the presence of high GTP (0.1 mM) concentrations, however, insulin was shown to inhibit adenylate cyclase activity. This effect was dose-dependent, exhibiting an EC50 (median effective concentration) of 3 microM for GTP. Elevated glucagon concentrations blocked the inhibitory effect of insulin in a dose-dependent fashion, with an EC50 of 1 nM. The insulin inhibition was dose-dependent (EC50 = 90 pM). The inhibitory effects of insulin were abolished using membranes from either glucagon-desensitized hepatocytes or cholera-toxin-treated hepatocytes. If either Mn2+ replaced Mg2+ in adenylate cyclase assays or Na+ was removed from the assay mixtures then insulin failed to exert any inhibitory effect. It is suggested that insulin exerts its action on adenylate cyclase through an inhibitory guanine nucleotide protein. This is integrated with the proposal [Heyworth, Rawal & Houslay (1983) FEBS Lett. 154, 87-91; Heyworth, Wallace & Houslay (1983) Biochem. J. in the press] that insulin mediates a variety of cellular effects through a specific guanine nucleotide regulatory protein and associated protein kinase(s).

Adenylyl Cyclase Inhibitors↗
PubMed1996

Flux control exerted by overt carnitine palmitoyltransferase over palmitoyl-CoA oxidation and ketogenesis is lower in suckling than in adult rats.

We examined the potential of overt carnitine palmitoyltransferase (CPT I) to control the hepatic catabolism of palmitoyl-CoA in suckling and adult rats, using a conceptually simplified model of fatty acid oxidation and ketogenesis. By applying top-down control analysis, we quantified the control exerted by CPT I over total carbon flux from palmitoyl-CoA to ketone bodies and carbon dioxide. Our results show that in both suckling and adult rat, CPT I exerts very significant control over the pathways under investigation. However, under the sets of conditions we studied, less control is exerted by CPT I over total carbon flux in mitochondria isolated from suckling rats than in those isolated from adult rats. Furthermore the flux control coefficient of CPT I changes with malonyl-CoA concentration and ATP turnover rate.

Animals↗
PubMed2001

N-acetyl-L-cysteine exerts direct anti-aggregating effect on human platelets.

BACKGROUND: N-acetyl-L-cysteine, a thiol compound, has been shown to potentiate the inhibition of platelet aggregation exerted by organic nitrates and to increase the anti-aggregating effect of L-arginine, which promotes endogenous synthesis of nitric oxide (NO) acting as substrate of platelet constitutive nitric oxide synthase (NOS). It is not known whether this thiol can exert direct effects on platelet aggregability. MATERIALS AND METHODS: 14 healthy male volunteers provided platelet samples to investigate whether N-acetyl-L-cysteine directly influences platelet function and intraplatelet levels of 3',5' cyclic guanosine monophosphate (cGMP), which represents the second messenger involved in NO-induced antiaggregation. Some experiments were repeated in the presence of NOS inhibitor NG-monomethyl-L-arginine (L-NMMA), of nitric oxide-sensitive guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), of the selective cGMP phosphodiesterase inhibitor zaprinast and of calcium ionophores (A23187, ionomycin). RESULTS: N-acetyl-L-cysteine at 3000-6000 micromol L-1 decreases the responses of human platelets both in platelet-rich plasma (aggregation induced by adenosine 5-diphosphate) and in whole blood (aggregation induced by collagen). The anti-aggregating effect was prevented by preincubation with L-NMMA and guanylyl cyclase inhibitor ODQ. In resting platelets, N-acetyl-L-cysteine increased the levels of cGMP starting from a concentration of 3000 micromol L-1. Permeabilized platelets exhibited an increased sensitivity to the anti-aggregating effect of N-acetyl-L-cysteine. Also, cGMP phosphodiesterase inhibition or the increase in calcium availability, enhanced N-acetyl-L-cysteine effects on platelets. CONCLUSION: N-acetyl-L-cysteine exerts direct anti-aggregating effects through an increased bioavailability of platelet nitric oxide.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1999

Brain-derived neurotrophic factor exerts opposing effects on beta2-adrenergic receptor according to depolarization status of cerebellar neurons.

To investigate the molecular mechanisms underlying brain-derived neurotrophic factor (BDNF)-controlled synaptic plasticity, we studied beta2-adrenergic receptor (beta2-AR) expression in cultured cerebellar granule cells. We show that, depending on the state of depolarization, BDNF exerts opposite effects on beta2-AR expression. In neurons maintained in low K+ medium (5 mM K+) that will enter apoptosis, BDNF increases beta2-AR and beta2-AR transcripts. In contrast, in depolarized neurons (high K+ medium, 25 mM K+) BDNF represses beta2-AR expression. The use of reporter genes (driven by the beta2-AR promoter or restricted regulatory elements) revealed that BDNF exerts its opposite effects at the transcriptional level by recruiting a cyclic AMP response element (CRE) and the trans-acting factor CRE binding protein. These results provide the first evidence that a neurotrophin, e.g., BDNF, may exert an opposite effect on receptor expression and function (beta2-AR) according to the depolarization status of the neuron. Based on this finding, we propose that BDNF not only mediates neuronal survival, but is also involved in the modulation of the general sensitivity of the neuron to external signals, thus maintaining its optimal functional integration within the neuronal network.

Animals↗
PubMed1996

Unusual development of acute exertional compartment syndrome due to delayed diagnosis. A case report.

Our report describes the case of a 20 year old man who developed an acute exertional anterior tibial compartment syndrome after playing soccer for five minutes. No trauma was reported. Correct diagnosis was delayed for 18 hours, because pain was misinterpreted as resulting from acute muscular tetanic spasm induced by hyperventilation. Fasciotomy was contributed. After one year, the patient complained of early fatigue. Electromyographically the reinnervation had not yet been completed. This case illustrates the necessity for careful observation of non-trauma related acute tibial anterior pain appearing even at the beginning of strenuous exercise. It is important to recognize the possibility of a very acute onset of exertional compartment syndrome that does not subside with rest. Only early diagnosis and fasciotomy can prevent severe complications of an acute exertional compartment syndrome.

Acute Disease↗
PubMed2000

The measurement of forces exerted during colonoscopy.

BACKGROUND: The widely varying forces used at colonoscopy have not been measured. An electronic device was designed to measure the forces exerted by the clinician on the endoscope during colonoscopy. METHODS: The device featured a handle designed in the shape of a hinged split cylinder that could be locked around the endoscope but readily moved up and down the insertion tube as the colonoscopy proceeded. This cylinder contained strain-gauges arranged so that the forces transmitted could be accurately measured. The device recorded the torque forces in addition to the push and pull forces exerted during diagnostic colonoscopy. RESULTS: In a series of 21 colonoscopies in 20 patients: peak pushing force = 4.4 kg, pulling force = -1.8 kg, anti-clockwise torque = 1.0 Newton meters, clockwise torque = 0.8 Newton meters. Percentage time force greater than 1 kg = 5%. Peak anal insertion force = 1.8 kg. CONCLUSIONS: These measurements represent the first accurate measurements of the forces exerted during colonoscopy. Reducing the force during colonoscopy is likely to diminish pain and reduce the risk of perforation. A knowledge of these forces may also help with the design of new instruments and models for teaching or research.

Adult↗
PubMed2000

Effect of foot movement and an elastic lumbar back support on spinal loading during free-dynamic symmetric and asymmetric lifting exertions.

The aim of this study was to assess the effect of an elastic lumbar back support on spinal loading and trunk, hip and knee kinematics while allowing subjects to move their feet during lifting exertions. Predicted spinal forces and moments about the L5/S1 intervertebral disc from a three-dimensional EMG-assisted biomechanical model, trunk position, velocities and accelerations, and hip and knee angles were evaluated as a function of wearing an elastic lumbar back support, while lifting two different box weights (13.6 and 22.7 kg) from two different heights (knee and 10 cm above knee height), and from two different asymmetries at the start of the lift (sagittally symmetric and 60 degrees asymmetry). Subjects were allowed to lift using any lifting style they preferred, and were allowed to move their feet during the lifting exertion. Wearing a lumbar back support resulted in no significant differences for any measure of spinal loading as compared with the no-back support condition. However, wearing a lumbar back support resulted in a modest but significant decrease in the maximum sagittal flexion angle (36.5 to 32.7 degrees), as well as reduction in the sagittal trunk extension velocity (47.2 to 40.2 degrees s(-1)). Thus, the use of the elastic lumbar back support provided no protective effect regarding spinal loading when individuals were allowed to move their feet during a lifting exertion.

Adult↗
PubMed2000

Implications of an adjustable bed height during standard nursing tasks on spinal motion, perceived exertion and muscular activity.

Manual handling is a source of occupational stress, particularly for nursing personnel. High levels of biomechanical strain are associated with lifting and transferring patients, especially when the tasks are performed in flexed and twisted positions that induce an increased risk of functional and musculoskeletal problems. The use of adjustable beds in nursing practice has been suggested as a means of influencing working postures and reducing the muscular demands on nurses. The purpose of this study was to investigate the effects on spinal motion, muscular activity and perceived exertion when nurses had the opportunity to adjust bed height. The measures recorded during the conduct of standardized patient handling tasks were the changes in posture (inclination) and in shape (sagittal bending, side bending, axial rotation). Muscular activity was measured using surface electromyography. Perceived exertion was rated using the 15-graded Borg scale. The range of motion was not influenced by the adjustment of bed height, but rather a shift of the time duration histogram was noticed in the direction of the erect, safer position. The time spent in the safe zone of spinal motion near the erect position was significantly increased and was significantly decreased in the potential health-hazardous zones of spinal motion in the extreme positions. No differences in muscular activity or in perceived exertion were found between the two bed height conditions for any of the muscle groups. It was concluded that the quality of spinal motion is enhanced when the opportunity of adjusting the bed height is offered.

Adult↗
PubMed1999

Severe liver failure in exertional heat stroke.

Exertional heat stroke usually occurs in warm climates. Increased serum levels of liver enzymes is a common finding in this condition, whereas liver failure is a more rare event that carries a poor prognosis. Liver transplantation has been recommended as treatment in cases of severe liver failure, but no long-term survival after this procedure in exertional heat stroke has been described. We report the case of a 31-year-old man who had a heat stroke after running 5 km at 21 degrees C. He developed severe liver damage, with serum alanine aminotransferase (ALAT) activities increasing to 16,410 U/l (reference values, 10-50 U/l) after 48 h, concomitantly with a pronounced coagulation disturbance, with Normotest (NT) decreasing to 12% (international normalized ratio (INR) = 4.2) (reference values, 70%-130% for NT and 0.8-1.2 for INR). A liver biopsy on the 5th day after the incident showed extensive liver cell necrosis. The patient was referred to be considered for liver transplantation but recovered completely on conservative treatment. We conclude that exertional heat stroke is a diagnostic possibility also in temperate climates and that severe liver failure may ensue. The liver injury is reversible, and the indications for liver transplantation in this situation have not been clarified.

Adult↗
PubMed1995

Physiological and perceived exertion responses to six modes of submaximal exercise.

In order to compare the cardiovascular and perceived exertion responses to 6 modes of exercise, 10 male recreational exercisers were habituated to treadmill jogging, stationary skiing, shuffle skiing, stepping, stationary cycling, and stationary rowing. After following a specific dietary preparation, each participant performed a 20-min exercise bout at a constant 14-rating of perceived exertion (RPE) followed by a second exercise bout at 60% of mode-specific peak oxygen consumption (VO2peak). On the 14-RPE trial, oxygen consumption (VO2) and oxygen pulse were significantly higher during jogging than during other exercise modes, and oxygen pulse was higher during skiing than during shuffle skiing. On the 60% VO2peak bout, oxygen pulse was significantly higher during jogging than during shuffle skiing, cycling and rowing. Ratings of perceived exertion were significantly higher during cycling than during jogging. These results indicated that a variety of exercise modes can be used to develop fitness, but jogging may induce a slightly more favorable VO2-to-RPE relationship.

Adult↗