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At least 361 records · Page 20Linked to original sources

PubMed2003

Inclined running increases pulmonary haemorrhage in the Thoroughbred horse.

REASONS FOR PERFORMING STUDY: Capillary stress failure-induced (exercise-induced) pulmonary haemorrhage (EIPH) during intense running in horses is thought to involve both intravascular (i.e. mean pulmonary arterial pressure [Ppa] > 100 mmHg) and extravascular (e.g. negative inspiratory pressure swings) mechanisms. HYPOTHESIS: That inclined running would reduce breathing frequency (coupled to stride frequency) and increase tidal volume thus increasing lung volume changes and intrapleural pressure swings resulting in more pronounced EIPH. METHODS: Six Thoroughbred horses were run to volitional fatigue (incremental step test) on a level (L) and inclined (I; 10%) treadmill in random order. Pulmonary minute ventilation, arterial blood gases and mean Ppa were obtained during each run while EIPH severity was quantified via bronchoalveolar lavage (BAL) 30 mins post run. RESULTS: Time to fatigue did not differ between trials (P > 0.05). At end-exercise, breathing frequency was reduced (L, 127.8 +/- 3.0; I, 122.6 +/- 2.1 breaths/min; P < 0.05) and tidal volume increased (L, 11.5 +/- 0.6; I, 13.1 +/- 0.5 L; P < 0.05) during inclined running. No differences existed in end-exercise plasma [lactate] between trials (L, 24.5 +/- 2.9; I, 26.2 +/- 3.4 mmol/l, P > 0.05); however, the mean peak Ppa was reduced during the inclined run (L, 105+5; I, 96 +/- 4 mmHg, P < 0.05). In the face of reduced Ppa, EIPH severity was increased significantly (P < 0.05) during the inclined vs. level run (L, 37.0 +/- 11.7; I, 49.6 +/- 17.0 x 10(6) red blood cells/ml BAL fluid). CONCLUSIONS: Although inclined running lowered peak Ppa, EIPH severity was increased. It is likely that this effect resulted, in part, from an altered ventilatory pattern (i.e. increased tidal volumes and associated intrapleural pressure changes). POTENTIAL RELEVANCE: This conclusion supports an important role for extravascular factors in the aetiology of EIPH.

Animals↗

PubMed2005

Wheel-running and rest activity pattern interaction in two octodontids (Octodon degus, Octodon bridgesi).

Wheel-running and other non-photic stimuli influence the rest-activity pattern of diurnal and nocturnal mammals. A day to night inversion of phase preference of activity was described among Octodon degus, when exposed to ad-libitum wheel running. We have studied the rest-activity pattern response in presence of ad libitum wheel-running in wild-captured male individuals from two species of genus Octodon: O. degus (n = 9, crepuscular-diurnal) and O. bridgesi (n = 3, nocturnal). After two months of habituation to laboratory conditions, recordings were performed in isolation chambers under a 12:12 light-dark schedule with or without access to a running wheel. Actograms were constructed from data obtained by an automated acquisition system. O. bridgesi were also recorded under constant darkness, with or without access to wheel-running. Entrained to the light-dark schedule, a crepuscular pattern of activity was evident for O. degus, whereas O. bridgesi displayed a robust nocturnal chronotype. The activity of O. degus observed during the dark phase was enhanced when wheel-running was allowed. No significant change in phase preference was observed for O. bridgesi when wheel-running was allowed. A lengthening of endogenous period was observed in O. bridgesi after wheel-running exposure under constant darkness. Nocturnal and diurnal octodontids exhibit different masking responses to wheel-running.

Animals↗

PubMed1994

Maximal oxygen uptake, anaerobic threshold and running economy in women and men with similar performances level in marathons.

Sex differences in running economy (gross oxygen cost of running, CR), maximal oxygen uptake (VO2max), anaerobic threshold (Th(an)), percentage utilization of aerobic power (% VO2max), and Th(an) during running were investigated. There were six men and six women aged 20-30 years with a performance time of 2 h 40 min over the marathon distance. The VO2max, Th(an), and CR were measured during controlled running on a treadmill at 1 degree and 3 degrees gradient. From each subject's recorded time of running in the marathon, the average speed (vM) was calculated and maintained during the treadmill running for 11 min. The VO2max was inversely related to body mass (mb), there were no sex differences, and the mean values of the reduced exponent were 0.65 for women and 0.81 for men. These results indicate that for running the unit ml.kg-0.75.min-1 is convenient when comparing individuals with different mb. The VO2max was about 10% (23 ml.kg-0.75.min-1) higher in the men than in the women. The women had on the average 10-12 ml.kg-0.75.min-1 lower VO2 than the men when running at comparable velocities. Disregarding sex, the mean value of CR was 0.211 (SEM 0.005) ml.kg-1.m-1 (resting included), and was independent of treadmill speed. No sex differences in Th(an) expressed as % VO2max or percentage maximal heart rate were found, but Th(an) expressed as VO2 in ml.kg-0.75.min-1 was significantly higher in the men compared to the women. The percentage utilization of fcmax and concentration of blood lactate at vM was higher for the female runners.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1990

Significance of the contribution of aerobic and anaerobic components to several distance running performances in female athletes.

To assess the most important determinant for successful distance running (800 m, 1500 m and 3000 m events) in female athletes, measurements of several anaerobic indices were made (peak power, mean power) using the Wingate anaerobic test (WAnT), and aerobic indices such as oxygen uptake (VO2) or running velocity (v) at lactate threshold (LT), VO2 or v at onset of blood lactate accumulation (OBLA), running economy (RE), and maximal oxygen uptake were determined using the incremental treadmill test. The RE was represented by a VO2 value measured at 240 m.min-1 of a standard treadmill velocity. A stepwise multiple regression analysis (SAS stepwise procedure) combined the best features of forward inclusion and backward elimination to determine the most important factors in predicting the performance of running these distances as dependent variables. The stepwise procedure showed that the blood lactate variables such as LT and/or OBLA are highly correlated with, and contributed to predicting performance running 800 m-3000 m, whereas the anaerobic component was related only to running 800 m. In conclusion, blood lactate variables account for a large part of the variation in distance running performance in female as in male runners. The component of the anaerobic system which can be measured by the WAnT was shown to contribute to performance in running 800 m, but not in longer distances.

Adult↗

PubMed1995

Heart rate and oxygen uptake relationship: a comparison of loaded marching and running in women.

Heart rate (beats.min-1; fc) measured during marching with a load is often used to predict the oxygen cost (l.min-1; VO2) of the activity. The prediction comes from the fc/VO2 relationship determined from laboratory measures of fc and VO2 during treadmill running. Studies in men have suggested that this may not be appropriate although this has yet to be examined in women. This study, therefore, compared the fc/VO2 relationship between loaded marching and maximal running protocols in women. Sixteen female subjects [mean (SD), age 21.9 (2.3) years, height 6 (0.06) m, weight 62.6 (7.6) kg] had their fc (from three-lead chest electrodes) and VO2 measured first during standard treadmill run protocols, and again 1 week later during loaded marching protocols. The slopes and intercepts determined from linear regression of fc on VO2 for each individual for each protocol were compared as were the maximal fc(fcmax), VO2 and ratings of perceived exertion (RPE) from the last work period of each protocol in paired t-tests. The fc/VO2 slopes (P < 0.01) and intercepts (P < 0.05) differed significantly between loaded marching and running. fcmax for loaded marching were 90% of fcmax for running (P < 0.01) and VO2peak for loaded marching were 80% of those for running (P < 0.01). However, RPE at the final levels for the two protocols were not significantly different. The data suggest that in women the fc/VO2 relationships for loaded marching and for running are different. This difference is similar to that found in men when speed is held constant and the load and gradient are varied. The results suggest that it would be erroneous to use fc and VO2 measured during running protocols in the laboratory to estimate energy expenditure and work intensity during loaded marching in the field.

Adult↗

PubMed2002

Differences in leg muscle activity during running and cycling in humans.

Delta (delta) efficiency is defined as the ratio of an increment in the external mechanical power output to the increase in metabolic power required to produce it. The purpose of the present study was to investigate whether differences in leg muscle activity between running and cycling can explain the observed difference in delta efficiency between the two activities. A group of 11 subjects performed incremental submaximal running and cycling tests on successive days. The delta efficiencies during running and cycling were based on five exercise stages. Electromyograph (EMG) measurements were made of three leg muscles (gastrocnemius, vastus lateralis and biceps femoris). Kendall's correlation coefficients between the mean EMG activity and the load applied were calculated for each muscle, for both running and cycling. As expected, the mean delta efficiency during running (42%) was significantly greater than that during cycling (25%). For cycling, all muscles showed a significant correlation between mean EMG activity and the load applied. For running, however, only the gastrocnemius muscle showed a significant, but low correlation ( r=0.33). The correlation coefficients of the vastus lateralis and biceps femoris muscles were not significantly different from 0. The results were interpreted as follows. In contrast to cycling, which includes only concentric contractions, during running up inclines eccentric muscle actions play an important role. With steeper inclines, more concentric contractions must be produced to overcome the external force, whereas the amount of eccentric muscle actions decreases. This change in the relative contribution of concentric and eccentric muscle actions, in combination with the fact that eccentric muscle actions require much less metabolic energy than concentric contractions, can explain the difference between the running and cycling delta efficiency.

Adult↗

PubMed2004

Peak oxygen uptake during running and arm cranking normalized to total and regional skeletal muscle mass measured by magnetic resonance imaging.

The purposes of our study were to determine the peak oxygen uptake (V(.) >O(2peak)) per total or regional skeletal muscle (SM) mass using magnetic resonance imaging (MRI) and to investigate the relationships between SM mass and V(.) >O(2peak) during running and arm cranking. Eight male college swimmers aged 18-22 years [mean (SD) age 20.0 (1.3) years] were recruited to participate in this study. V(.) >O(2) during running and arm cranking were measured using an automated breath-by-breath mass spectrometry system. Contiguous MRI slices were obtained from the first vertebra cervicale to the malleolus lateralis (1.0-cm slice thickness, 0-cm inter-slice gap), resulting in a total of approximately 156 images for each subject. The absolute V(.) O(2peak) and the V(.) O(2peak) per body mass during running and arm cranking were 3.6 (0.6) l.min(-1), 54.4 (5.9) ml.min(-1).kg(-1) and 2.5 (0.5) l.min(-1), 36.9 (5.3) ml.min(-1).kg(-1), respectively. The absolute V(.) O(2peak) was higher ( P <0.05) during running than during arm cranking, but not the V(.) O(2peak) per regional area SM mass. The lower body SM mass was correlated to the V(.) O(2peak) during running ( r =0.95, P <0.001). All measurements and calculated values were expressed as the mean (SD) for the eight subjects. To eliminate the influence of body mass and fat-free mass (FFM), a regression analysis was performed on the mass-residuals of the V(.) O(2peak) during running and the lower body SM mass. The residuals of lower body SM mass were correlated to the residuals of V(.) O(2peak) during running, with respect to body mass ( r =0.90, P <0.001) and FFM ( r =0.82, P <0.05). These results suggest that the MRI-measured lower body SM mass was closely associated to the absolute V(.) O(2peak) during running, independently of body mass or FFM, and that the V(.) O(2peak) per regional SM mass corresponded, regardless of the type of exercise (upper or lower body).

Adolescent↗

PubMed2006

Adaptational phenomena and mechanical responses during running: effect of surface, aging and task experience.

The goals of the study were to identify adaptational phenomena in running mechanics over a variety of surfaces due to age related changes in the muscle-tendon units (MTUs) capacities, to examine whether running experience is associated with adaptational effects on running mechanics over a variety of surfaces even at old age, and to investigate whether surface condition affects running mechanics. The investigation was executed on 30 old and 19 young including 29 runners and 20 non-active subjects. In a previous study we documented that the older had lower MTUs capacities. In the present study running mechanics were analysed as the same subjects ran at 2.7 m/s over three surfaces having different compliance. Surface condition did not affect centre of mass trajectory, duty factor or joint kinetics (P > 0.01). Older react to the reduced MTUs capacity by increasing duty factor and benefiting from a mechanical advantage for the triceps surae MTU and a lower rate of force generation on all surfaces (P < 0.01). Runners displayed lower average horizontal forces and a higher mechanical advantage for the quadriceps femoris MTU for all surfaces (P < 0.01). The results provided strong evidence on that running strategy remained essentially unchanged over a variety of surfaces. Adaptive improvements in running mechanics due to task experience were present for all surfaces and did not depend on age. We further concluded that older adults were able to recalibrate their running strategy to adjust the task effort to the reduced MTUs capacities in a feedforward control manner for a variety of mechanical environments.

Adaptation, Physiological↗

PubMed2006

Constant versus variable-intensity during cycling: effects on subsequent running performance.

The aim of this study was to investigate the metabolic responses to variable versus constant-intensity (CI) during 20-km cycling on subsequent 5-km running performance. Ten triathletes, not only completed one incremental cycling test to determine maximal oxygen uptake and maximal aerobic power (MAP), but also three various cycle-run (C-R) combinations conducted in outdoor conditions. During the C-R sessions, subjects performed first a 20-km cycle-time trial with a freely chosen intensity (FCI, approximately 80% MAP) followed by a 5-km run performance. Subsequently, triathletes were required to perform in a random order, two C-R sessions including either a CI, corresponding to the mean power of FCI ride, or a variable-intensity (VI) during cycling with power changes ranging from 68 to 92% MAP, followed immediately by a 5-km run. Metabolic responses and performances were measured during the C-R sessions. Running performance was significantly improved after CI ride (1118 +/- 72 s) compared to those after FCI ride (1134 +/- 64 s) or VI ride (1168 +/- 73 s) despite similar metabolic responses and performances reported during the three cycling bouts. Moreover, metabolic variables were not significantly different between the run sessions in our triathletes. Given the lack of significant differences in metabolic responses between the C-R sessions, the improvement in running time after FCI and CI rides compared to VI ride suggests that other mechanisms, such as changes in neuromuscular activity of peripheral skeletal muscle or muscle fatigue, probably contribute to the influence of power output variation on subsequent running performance.

Adult↗

PubMedDate not supplied

Serum hormone and myocellular protein recovery after intermittent runs at the velocity associated with VO(2max).

The responses of serum myocellular proteins and hormones to exercise were studied in ten well-trained middle-distance runners [maximal oxygen consumption (VO(2max)) = 69.4 (5.1) ml x kg(-1) x min(-1)] during 3 recovery days and compared to various measures of physical performance. The purpose was to establish the duration of recovery from typical intermittent middle-distance running exercises. The subjects performed, in random, order two 28-min treadmill running exercises at a velocity associated with VO(2max): 14 bouts of 60-s runs with 60 s of rest between each run (IR(60)) and 7 bouts of 120-s runs with 120 s of rest between each run (IR(120)). Before the exercises (pre- exercise), 2 h after, and 1, 2 and 3 days after the exercises, the same series of measurements were performed, including those for serum levels of the myocellular proteins creatine kinase, myoglobin and carbonic anhydrase III (S-CK, S-Mb and S-CA III, respectively), serum hormones testosterone, Luteinizing hormone, follicle-stimulating hormone and cortisol (S-testosterone, S-LH, S-FSH and S-cortisol, respectively) and various performance parameters: maximal vertical jump height (CMJ) and stride length, heart rate and ratings of perceived exertion during an 8-min run at 15 km x h(-1) (SL(15 km x h(-1)), HR(15 km x h(-1)) and RPE(15 km x h(-1)), respectively). Two hours after the end of both exercise bouts the concentration of each measured serum protein had increased significantly (P < 0.001) compared to the pre-exercise level, but there were no changes in SL(15 km x h(-1)) or CMJ. During the recovery days only S-CK was significantly raised (P < 0.01), concomitant with a decrease in CMJ (P < 0.01) and an increase in RPE(15 km x h(-1)) (P < 0.01). Hormone levels remained unchanged compared to the pre-exercise levels during the recovery days and there were no significant differences between the two exercise bouts in any of the observed post-exercise day-to-day responses. With the exception of S-CK, after IR(120) the post-exercise responses returned to their pre-exercise levels within the 3 days of recovery. The present findings suggest that a single 28-min intermittent middle-distance running exercise does not induce changes in serum hormones of well-trained runners during recovery over 3 days, while changes in S-CK, CMJ and RPE(15 km x h(-1)) indicate that 2-3 days of light training may be needed before the recovery at muscle level is complete.

Adult↗

PubMed1995

Voluntary running in male S5B/P1Ras rats fed high fat or high carbohydrate diets.

Nineteen week-old male S5B/P1Ras (S5B) rats were randomly assigned to one of 4 groups as follows: (a) activity wheel access (running)/high fat diet (RF); (b) no activity wheel access (non-running)/high fat diet (NRF); (c) activity wheel access (running)/high carbohydrate diet (RC); and (d) no activity wheel access (non-running)/high carbohydrate diet (NRC) for the seven weeks duration of the experiment. Throughout the 7 wk of the experiment, rats ran more during subsequent weeks than they did the previous week. RC rats ran more than RF rats as measured by the running slopes. All groups of rats lost weight at the initiation of the experiment but significantly more weight was lost by running rats than their nonrunning counterparts. The inguinal, epididymal and perirenal/retroperitoneal (P/R) fat depots weighed significantly less in the running than in the nonrunning groups. From among the 3 fat depots, the difference was greatest in the P/R depot. There were no diet or voluntary activity effects on plasma corticosterone concentrations except at week 2 when running rats had higher concentrations than nonrunning rats.

Adrenal Glands↗

PubMed1992

Scheduled running wheel activity indexes the specificity of pharmacological anorexia.

Nondeprived male Sprague-Dawley rats that were given scheduled access to running wheels for 60 min daily ran immediately and energetically. Intraperitoneal injections of 400 micrograms/kg pancreatic glucagon and 0.15 microgram/kg cholecystokinin octapeptide had no effect on scheduled running, but significantly inhibited feeding when the rats were offered condensed milk instead of access to the running wheels. This is consistent with the hypothesized function of these peptides as postprandial satiety signals. In contrast, 0.5 mg/kg amphetamine and 75 microM/kg LiCl, which produced similar degrees of anorexia, inhibited running by about 50%. Amphetamine, but neither peptide, also inhibited water drinking and disrupted the behavioral sequence of postprandial satiety. The distance run during scheduled running tests was inversely related to body weight, but the patterns of the drugs' effects were not altered by baseline running differences. Scheduled wheel running is a robust consummatory behavior that appears to provide a relatively valid, simple, and sensitive test of the behavioral specificity of pharmacological anorexia.

Amphetamine↗

PubMed2004

Voluntary running distance is negatively correlated with striatal dopamine release in untrained rats.

This study examined the relationship between voluntary running distance and glutamate- and K+-stimulated dopamine release in the striatum (nucleus accumbens and caudate-putamen) of male Long-Evans rats. Twenty-one rats were housed individually in cages with attached running-wheels for 1 week. There was a 19-fold variability between rats in voluntary running distances over this period (range = 2.3-44.6 km). The average distance completed during the week was 16 +/- 2.8 km. There was a strong positive correlation between the running distances completed during the first 24 h (day 1) and the last 24 h. Certain rats were therefore inclined to run from the start. The average daily running distance (2.4 +/- 0.4 km per day) was negatively correlated with the weight of the rat (r = -0.82). Glutamate-stimulated release of dopamine was not a significant predictor of voluntary running distance. However, the average daily running distance was negatively correlated with K+-stimulated dopamine release in the nucleus accumbens core and caudate-putamen but not the nucleus accumbens shell. The present findings suggest that decreased depolarization-induced release of striatal dopamine may be a predictor of hyperactivity. The results show, in a normal population of Long-Evans rats, that there are, at the end of the continuum, rats that display some of the neurochemical and behavioral characteristics of a rat model for attention-deficit hyperactivity disorder.

Analysis of Variance↗

PubMed2005

The consequences of uncontrollable stress are sensitive to duration of prior wheel running.

The behavioral consequences of uncontrollable stress, or learned helplessness (LH) behaviors, are thought to involve hyperactivity of serotonergic (5-HT) neurons in the dorsal raphe nucleus (DRN). Other brain regions implicated in LH and capable of affecting 5-HT systems, such as the bed nucleus of the stria terminalis (BNST), amygdala, and habenula, could contribute to DRN 5-HT hyperactivity during uncontrollable stress. Six weeks of wheel running prevents LH and attenuates uncontrollable stress-induced c-Fos expression in DRN 5-HT neurons, although the duration of wheel running necessary for these effects is unknown. In the current study, 6 but not 3, weeks of wheel running blocked the shuttle box escape deficit and exaggerated fear produced by uncontrollable tail shock in sedentary rats. Corresponding to the duration-dependent effects of wheel running on LH behaviors, 6 weeks of wheel running was required to attenuate uncontrollable stress-induced 5-HT neural activity, indexed by c-Fos protein expression, in the DRN and c-Fos expression in the lateral ventral region of the BNST. Wheel running, regardless of duration, did not affect c-Fos expression anywhere in the amygdala or habenula. These data indicate that the behavioral effects of uncontrollable stress are sensitive to the duration of prior physical activity and are consistent with the hypothesis that attenuation of DRN 5-HT activity contributes to the prevention of LH by wheel running. The potential role of the BNST in the prevention of LH by wheel running is discussed.

Animals↗

PubMed2006

Effects of chronic treadmill running on neurogenesis in the dentate gyrus of the hippocampus of adult rat.

Proliferating astrocytes and proliferating neuroblasts have been observed in the subgranular zone (SGZ) of the dentate gyrus (DG) in the hippocampus of adult rats under normal conditions. However, whether these proliferating cells are stimulated by running has not been determined. Using immunohistochemical techniques, we examined the effects of chronic treadmill running on proliferating astrocytes (PCNA+/GFAP+ cells), proliferating neuroblasts (PCNA+/DCX+ cells) and newly generated postmitotic neurons (DCX+/NeuN+ cells) in the DG of the hippocampus of adult rats and also characterized the morphological features of PCNA+/GFAP+ cells and PCNA+/DCX+ cells. PCNA+/GFAP+ cells with few processes and PCNA+/DCX+ cells without long processes were detected in the SGZ, and we determined that these are morphological features of the astrocytes and neuroblasts with proliferative ability. Chronic treadmill running (at a speed of 22 m/min, 30 min/days for 7 days) significantly increased the numbers of PCNA+/GFAP+ cells and DCX+/NeuN+ cells, and the number of PCNA+/DCX+ cells tended to increase by chronic treadmill running. These results indicate that chronic treadmill running stimulates the proliferation of astrocytes in the SGZ. Furthermore, the present study indicates that chronic treadmill running increases DCX+/NeuN+ cells that are detected in a transient stage during the neuronal maturation process. These events may be the cellular basis mediating both running-induced increases of new neurons in the DG of the hippocampus and running-induced improvement of learning and memory functions of adult rats.

Animals↗

PubMed2005

Information for step length adjustment in running.

The purpose of this study was to directly test the hypothesis that the tau parameter, as introduced by Lee et al. [Lee, D. N., Lishman, J. R., & Thomson, J. A. (1982). Regulation of gait in long jumping. Journal of Experimental Psychology: Human Perception and Performance, 8, 448-459] and Warren et al. [Warren, W. H., Young, D. S., & Lee, D. N. (1986). Visual control of step length during running over irregular terrain. Journal of Experimental Psychology: Human Perception and Performance, 12, 259-266], is the primary information used to regulate step length in running toward a ground target. Visual information available to research participants performing a facsimile of a long jump approach run was manipulated, and the effects on task performance and running gait were observed. Task performance and running gait were unaffected or minimally affected by (a) a perturbation of the normal optical expansion of the target, (b) elimination of global optical flow - including the focus of expansion, and (c) elimination or severe degradation of visual information about distance from the target as well as running velocity. The findings are inconsistent with notions that time-to-arrival with a ground target while running is predominantly specified optically by (a) local tau, (b) global tau, or (c) a distance/velocity computational strategy. A multisensory tau hypothesis regarding informational support for step length adjustment in running is offered.

Adaptation, Physiological↗

PubMed2002

A movement criterion for running.

The adjustment of the leg during running was addressed using a spring-mass model with a fixed landing angle of attack. The objective was to obtain periodic movement patterns. Spring-like running was monitored by a one-dimensional stride-to-stride mapping of the apex height to identify mechanically stable fixed points. We found that for certain angles of attack, the system becomes self-stabilized if the leg stiffness was properly adjusted and a minimum running speed was exceeded. At a given speed, running techniques fulfilling a stable movement pattern are characterized by an almost constant maximum leg force. With increasing speed, the leg adjustment becomes less critical. The techniques predicted for stable running are in agreement with experimental studies. Mechanically self-stabilized running requires a spring-like leg operation, a minimum running speed and a proper adjustment of leg stiffness and angle of attack. These conditions can be considered as a movement criterion for running.

Accidental Falls↗

PubMed2004

Effect of recovery modality on 4-hour repeated treadmill running performance and changes in physiological variables.

The purpose of this study was to compare the effectiveness of three different recovery modalities--active (ACT), passive (PAS) and contrast temperature water immersion (CTW)--on the performance of repeated treadmill running, lactate concentration and pH. Fourteen males performed two pairs of treadmill runs to exhaustion at 120% and 90% of peak running speed (PRS) over a 4-hour period. ACT, PAS or CTW was performed for 15-min after the first pair of treadmill runs. ACT consisted of running at 40% PRS, PAS consisted of standing stationary and CTW consisted of alternating between 60-s cold (10 degrees C) and 120-s hot (42 degrees C) water immersion. Run times were converted to time to cover set distance using critical power. Type of recovery modality did not have a significant effect on change in time to cover 400 m (Mean +/- SD; ACT 2.7 +/- 3.6 s, PAS 2.9 +/- 4.2 s, CTW 4.2 +/- 6.9 s), 1000 m (ACT 2.2 +/- 4.0 s, PAS 4.8 +/- 8.6 s, CTW 2.1 +/- 7.2 s) or 5000 m (ACT 1.4 +/- 29.0 s, PAS 16.7 +/- 58.5 s, CTW 11.7 +/- 33.0 s). Post exercise blood lactate concentration was lower in ACT and CTW compared with PAS. Participants reported an increased perception of recovery in the CTW compared with ACT and PAS. Blood pH was not significantly influenced by recovery modality. Data suggest both ACT and CTW reduce lactate accumulation after high intensity running, but high intensity treadmill running performance is returned to baseline 4-hours after the initial exercise bout regardless of the recovery strategy employed.

Adult↗