SEARCH · PubMed Health

Results for “Running”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,027 records · Page 57Linked to original sources

PubMed1988

The validity generalization of distance run tests.

The validity generalization model was used to examine the generalizability of the validity of distance run tests as measures of cardiorespiratory function. A literature search was conducted to identify studies in which distance run test scores were correlated with VO2 max scores obtained from a stress test on a treadmill. The data base was limited to runs of at least one mile or 9 min and the VO2 max scores expressed as mL.kg-1.min-1. The concurrent validity of distance run tests was not shown to be generalizable across all situations. When the data were analyzed by gender, the validity of distance run tests was more generalizable for women than for men. In the analysis of test scores for boys and girls, the validities appeared to be generalizable, although the results should be interpreted with caution owing to small samples sizes.

Adolescent↗

PubMed1987

[Physiological analysis of running performance: revision of the hyperbolic model].

1 This paper presents a physiological model for the analysis of the "running curve" (i.e. the relationship between running time and power output) (Table I and Fig. 1). This model is derived from the basic hyperbolic model (Eq. 2: Fig. 2 a) modified in order to take into account the slow adjustment of oxygen utilization and of glycolysis at the onset of exercise (Eq. 7) and the progressive reduction of average aerobic power sustained with increasing running time for races lasting longer than 7 min (Eq. 10; Fig. 2 b, 2 d). 2 This model provides a satisfactory smoothing of the running curve from 200 m to marathon. Average errors (in absolute value) between actual and estimated power output are 0.9 +/- 0.2% (+/- SE) and 1.3 +/- 0.4% for male and female world records respectively (Table II). The basic hyperbolic model (Ptc = A/tc + B) provides a satisfactory smoothing of the running curve on comparatively narrow ranges of events (Table III). 3 Estimations of anaerobic energy stores and of VO2 max made for male and female from world records (1,219 J.kg-1 and 76.4 ml.kg-1.min-1; 1,118 J.kg-1 and 67.8 ml.kg-1.min-1 respectively) are in reasonable agreement with expected values in elite runners (Table IV). 4 The model allows the computation of an objective measure of endurance, i.e. the so-called "ability to sustain a high percentage of VO2 max for a long period of time".(ABSTRACT TRUNCATED AT 250 WORDS)

Energy Metabolism↗

PubMed1987

Fluid shifts with successive running and bicycling performance.

Seven men and five women triathletes ran 10 km and bicycled 40 km at race pace for the purpose of studying changes in plasma, blood, and red blood cell volumes. A second trial followed 1 wk later with the order of exercise counterbalanced (running first-cycling second; cycling first-running second). Water consumption was measured by providing water bottles on the bike phase, at 3.2 and 6.7 km on the run phase, and at the transition area. Body weight was obtained at the start and end of each phase. A 10-ml blood sample was obtained just before starting and immediately upon finishing each phase. Changes in plasma volume, blood volume, and red cell volume were calculated from hematocrit and hemoglobin values. Changes in blood volume, plasma volume, and red cell volume did not differ between the sexes; therefore, results were combined. Sequential cycling and running caused significant hemoconcentration (-6 to -8% blood volume; -8 to -10% plasma volume) with moderate dehydration (-3 to -4% body weight) despite ad libitum fluid replacement. More severe fluid compartment shifts occurred on the initial phase regardless of exercise mode. Blood volume and plasma volume changes during the second mode of exercise were minor in extent with the major differences occurring in red cell volume. When fluid changes were calculated on a per hour basis, shifts were greater during running than during cycling.

Bicycling↗

PubMed1987

Plasma beta-endorphin responses to one-hour bicycling and running at 60% VO2max.

Ten adult male volunteers were studied to examine the effect on plasma beta-endorphin (B-EN) of bicycling and running for 1 h at 60% VO2max. All subjects were physically active and accustomed to both exercise modes (mean VO2max in ml X kg-1 X min-1; bicycling, 54; running, 59). Following preliminary VO2max tests, subjects participated in randomly ordered experimental sessions of bicycling and running for 1 h at loads requiring 60% of their mode-specific VO2max. Five subjects also participated in control sessions. Blood samples were collected immediately pre- and immediately post-exercise, and hematocrits were determined. Samples were centrifuged, separated, and plasma was stored at -50 degrees C until analysis for B-EN. Analysis involved separation of B-EN from beta-lipotropin by short column chromatography followed by radioimmunoassay. Despite an observed trend for elevated B-EN following exercise, there were no significant pre- to post-exercise differences (P greater than 0.05) in mean B-EN levels in any of the three sessions. Expressed as percentage change in B-EN, there were no significant differences between bicycling, running, or control. These results indicate that 1 h bicycling or running exercise at 60% VO2max does not consistently increase B-EN, and that responses are variable between individuals.

Adult↗

PubMed1985

Distance running in the 1980s: cardiovascular benefits and risks.

Although within the capacity of perhaps one to two percent of highly motivated patients after myocardial infarction, long-distance and marathon running do not confer on normal subjects immunity from coronary atherosclerosis or freedom from high grades of ventricular ectopy during running and nonrunning activities. The presence of significant coronary heart disease does not preclude participation in long-distance and marathon running, provided appropriate safety precautions are taken. There is no conclusive proof that the long-term prognosis is improved by long-distance or marathon running or by increasing the intensity of training above the generally accepted level of 60 to 80 percent of VO2 max. Marathon running for coronary patients and for coronary-prone persons remains experimental and awaits further scientific evaluation employing a prospective randomized study of subjects with angiographic proof of significant coronary artery disease.

Adaptation, Physiological↗

PubMed1985

Metabolic and cinematographic analysis of walking and running in men and women.

The purposes of this study were to compare the total metabolic costs and gait patterns of walking and running at self-selected, comfortable speeds in males and females. Total oxygen consumption was used to determine the metabolic cost, and cinematographic analysis was used to study the gait patterns of walking and running a distance of 1 km in 12 male and 12 female subjects. No significant sex difference was observed for the speed, vertical lift per stride, and total vertical lift per km of distance walked. Females ran at a significantly slower speed than males (P less than .01), but no significant sex difference was observed for the vertical lift per stride or total vertical lift per km of distance run. In both sexes, the gross and net energy costs of running were significantly greater (P less than .001) than those of walking when values were expressed as kcal . kg-1 . km-1 or cal . kg-1 . stride-1. No significant sex difference was observed in the gross or net metabolic cost of walking, whereas during running, the gross and net metabolic costs in kcal . kg-1 . km-1 were significantly higher (P less than .05) in females than in males. It was hypothesized that this sex difference was due to the cumulative effect of several factors which were biomechanical and metabolic in nature.

Adult↗

PubMed1984

Effects of different running programs on VO2 max, percent fat, and plasma lipids.

This study attempted to determine the effects of interval and continuous running on factors associated with cardiovascular health. Fifty-nine untrained men and women, ages 18-32 years, were randomly assigned to one of four groups: (1) 4 mile: running continuously at 75% of maximal heart rate (approximately 500 Cal/session) (2) 2 mile: running continuously at 75% of maximal heart rate (approximately 250 Cal/session) (3) interval: running one min at 90% maximal heart rate followed by three min of walking for eight sets (approximately 500 Cal/session) (4) control: no exercise program. The training was performed three times per week for 12 weeks. Treadmill VO2 max and percent body fat by hydrostatic weighing were assessed pre- and post training. Pre and post analyses were performed on plasma for triglycerides (TG), cholesterol (Chol), and high density lipoprotein cholesterol (HDL-C). Analysis of covariance indicated that only the interval group improved more than the control in VO2 max. Percent fat decreased in all exercise groups, but no program was superior. Changes in TG, Chol, or HDL-C were not different among groups. Although men and women differed on the pretests in VO2 max, percent fat, and HDL-C, their response to the training was similar. These results indicate that interval training may benefit aerobic capacity more than continuous running in young adults who have moderately high initial fitness levels. The data also indicate that cardiovascular fitness parameters are not easily altered by short term exercise in young active men and women.

Adipose Tissue↗

PubMed1984

Intravascular volume and protein responses to running exercise.

The roles of posture and mean skin temperature (Tsk) in determining intravascular volume and protein responses to running exercise were examined in 12 male subjects. Moving from a sitting to a standing position before exercise was always accompanied by a decrease in blood volume (BV), as indicated by increases in the hematocrit and hemoglobin concentration. Although neither the onset of running nor alterations in Tsk during running caused any further consistent change in BV, there was an acceleration of the rate at which protein entered the intravascular space. At the end of exercise and in recovery this led to an augmentation of intravascular protein. It is concluded that intravascular volume responses to running exercise are determined by the accompanying postural hemoconcentration, and that running per se and any imposed thermal stress have minimal effects on BV thereafter. A hypothesis is presented which accounts for the reportedly diverse effects of different forms of exercise on BV in terms of the posture-dependent BV being obtained immediately before exercise begins.

Adult↗

PubMed1982

Exercise-induced asthma after walking, running and cycling.

Bronchial response to 6 min exercise performed as treadmill-walking, treadmill-running, ergometer bicycling and free running were compared in 11 subjects with exercise-induced asthma (EIA). The study was performed under control of air temperature and relative humidity. The three different types of exercise were performed on consecutive days, and the ventilation was monitored using pneumotachography and rating of perceived exertion (RPE). The decrease in peak expiratory flow after treadmill-running was 25.5 +/- 4.5% (mean +/- SEM), after bicycle ergometer exercise 26.0 +/- 3.0%, after treadmill-walking 26.0 +/- 3.0% and after free running 27.0 +/- 3.5%. No statistical difference in bronchial response was demonstrated between the four types of exercise. The total ventilation for the 6 min period of exercise was 421, 411 and 427 litres for treadmill-walking, treadmill-running and bicycle ergometer exercise, respectively. It is concluded that the type of work is of little importance in EIA.

Adult↗

PubMed1981

The maximal steady state versus selected running events.

To investigate the relationship between the maximal steady state (MSS) and selected running events, seven males (mean = 37.6 years) who were experienced competitive distance runners were studied. From a series of 10-min steady-state treadmill runs, MSS (treadmill velocity, VO2, or heart rate where lactic acid concentration was 2.2 mM/L of venous blood) was determined for all subjects. Treadmill velocity at MSS averaged 258.9 +/- 29.0 m/min. The subjects subsequently performed maximal time trials or races at 13.7 m (15 yd), 45.7 m (50 yd), 402.3 m (440 yd), 3.22 km (2 miles), 8.05 km (5 miles), 16.09 km (10 miles), and 20 km (12.44 miles). Running paces for the 402.3-m, 3.22-km, 8.05-km, 16.09-km, and 20-km distances were all correlated significantly with the treadmill pace at MSS (r = 0.84 to 0.995). The highest correlation was between the MSS treadmill velocity and the 8.05-km pace. The mean for a 6.44-km (4 miles) flat section of the 16.09-km run was identical to the mean treadmill velocity at MSS (258.9 m/min). These data indicate that the pace for essentially aerobic events (3.22 km to 20 km) can be closely approximated by knowledge of a runner's MSS, or conversely that the MSS can be predicted very closely from the pace during an all-out 3.22-km, 8.05 km, 16.09-km, or 20-km run.

Adult↗

PubMed1993

Function of mono- and biarticular muscles in running.

In this study the function of leg muscles during stretch-shortening cycles in fast running (6 m.s-1) was investigated. For a single stance phase, kinematics, ground reaction forces, and EMG were recorded. First, rough estimates of muscle force, obtained by shifting the EMG curves +90 ms, were correlated with origin-to-insertion velocity (VOI). Second, active state and internal muscle behavior were estimated by using a muscle model that was applied for soleus and gastrocnemius. High correlations were found between estimates of muscle force and VOI time curves for mono-articular hip, knee, and ankle extensor muscles. The correlation coefficients for biarticular muscles were low. The model results showed that active state of gastrocnemius was high during increase of origin-to-insertion length (LOI), whereas active state of soleus was low during the start of increase of LOI and rose to a plateau at the time lengthening ended and shortening started. It seems that the difference in stimulation between gastrocnemius and soleus is a compromise between minimizing energy dissipation and using the stretch-shortening cycle optimally. Furthermore, it was found that the net plantar flexion moment during running reached a value of 302 Nm, which was 158% and 127% higher than the peak values reached in maximal jump and sprint push-offs, respectively. It was argued that the higher mechanical output in running than in jumping could be ascribed to the utilization of the stretch-shortening cycle in running. The higher values in running compared with sprinting, however, may lie in a difference in muscle stimulation.

Adult↗

PubMed1993

Interrelationships between mechanical power, energy transfers, and walking and running economy.

The interrelationships between aerobic demand, kinematic and kinetic-based estimates of mechanical power output and energy transfer, and total body angular impulse (summation of net joint moments integrated with respect to time over a stride) were quantified for walking at 1.69 m.s-1 and running at 3.35 m.s-1 to assess the ability of these various biomechanical expressions to explain interin-dividual differences in walking and running economy. Fourteen healthy men participated in the walking study and 16 recreational male runners were subjects for the running analysis. Each subject performed treadmill locomotion for determination of aerobic demand and overground locomotion from which biomechanical measures were quantified. It was expected that mechanical power and angular impulse expressions would correlate positively with aerobic demand while energy transfer expressions would correlate negatively. Correlations between aerobic demand and power estimates primarily were positive, but explained no more than 32% of the variability in walking or running VO2 (center of mass model: 0.22 < r < 0.57; segment-based model: -0.02 < r < 0.20; kinetic model: -0.07 < r < 0.22). Total body angular impulse also correlated positively with aerobic demand (0.32 < r < 0.42). Energy transfer expressions from the various analytical models showed no consistent relationship with aerobic demand, either in terms of magnitude or direction (-0.26 < r < 0.48). It was concluded that mechanical power, energy transfer, and angular impulse expressions frequently used in analyses of gait explain only a small proportion of normal interindividual variability in the aerobic demand at a given speed of walking or running.

Biomechanical Phenomena↗

PubMed1977

Oxygen cost of running in trained and untrained men and women.

The purpose of this study was to compare the oxygen cost of running as it relates to speed of running among the following four groups: trained male distance runners, trained female distance runners, untrained but active men and women. Each subject was given a series of treadmill tests during which Vo2 was measured at submaximal work loads. The linear regression equation was utilized to compute the relationship between Vo2 and running speed for each groups. The results indicated that the rate of increase in Vo2 for a given increase in running speed could be represented as a straight line and was the same for all groups (P greater than .05). The trained male runners had a significantly lower Vo2 (P less than .05) than those of the other three groups at any measured speed. The trained females and untrained males had significantly lower Vo2s than the untrained females (P less than .05) at any of the given range of speeds. No significant differences were observed between the untrained mean and trained women (P greater than .05). It was concluded that there were differences in the oxygen cost of running not only between the trained and untrained groups but also between males and females.

Adult↗

PubMed1995

The effects of sodium bicarbonate and sodium citrate on 600 m running time of trained females.

The effects of sodium bicarbonate and sodium citrate ingestion on 600 m running performance were assessed in 11 female track athletes and four trained female non-athletes. The subjects ingested either sodium bicarbonate (NaHCO3), sodium citrate or placebo approximately 2.5 hrs prior to the test runs in doses of 0.3 g/kg body weight in a double blind cross over design. Prior to and after exercise NaHCO3, H+, and lactate (HLa) concentrations were measured and running times were recorded. Pre- and post-experiment baseline testings were also performed. Data analysis was conducted using a Manova Repeated Measures design and dependent "t"-test. Although differences in running times were found 121.5 s, 119.9 s, 120.4 s in bicarbonate, citrate and placebo treatments respectively, they were not significant. The pH and concentrations of NaHCO3 were significantly elevated prior to and after the exercise when alkalinizing agents were ingested (p < 0.001). In bicarbonate treatment, prior to exercise pH was 7.40 and [NaHCO3] was 28.4 mEq/l, and after the exercise pH was 7.14 and [NaHCO3] was 17.9 mEq/l. In citrate treatment, prior to exercise pH was 7.40 and [NaHCO3] was 27.1 mEq/l, and after the exercise pH was 7.13 and [NaHCO3] was 16.6 mEq/l. There were no significant differences among the pre-exercise (2.3 mmol/l, 2.1 mmol/l, 2.2 mmol/l in bicarbonate, citrate and placebo treatments respectively) and after-exercise (11.8 mmol/l, 11.9 mmol/l, 11.0 mmol/l bicarbonate, citrate and placebo, respectively) HLa concentrations. This study demonstrated that, although alkali ingestion resulted in significant shifts in the blood acid-base balance, it failed to affect the 600 m running performance.

Acid-Base Imbalance↗

PubMed1997

Both neuropeptide Y and serotonin are necessary for entrainment of circadian rhythms in mice by daily treadmill running schedules.

This study investigated the role of the suprachiasmatic nucleus (SCN) circadian pacemaker and its neuropeptide Y (NPY) and serotonin (5-HT) afferents in entrainment (synchronization) of mouse circadian rhythms by treadmill running. Blind C57BL/6j mice were run in treadmills for 3 hr/d for 3-10 weeks after receiving radio-frequency lesions of the SCN or the intergeniculate leaflet (IGL, the source of SCN NPY) or infusions of the 5-HT neurotoxin 5,7-DHT into the SCN area. Of 25 intact mice, 22 entrained and three showed period (tau, the mean duration of the circadian cycle) modulations to scheduled running. Arrhythmic SCN-ablated mice did not synchronize to scheduled running in a way suggestive of circadian pacemaker mediation. Of 15 mice with IGL lesions, only two with partial lesions entrained. Mice with complete IGL lesions (five), confirmed by immunocytochemistry, showed no entrainment or tau changes. Of 19 mice with 5-HT lesions, only two with partial lesions entrained. All but two mice with complete (10) or nearly complete (4) 5-HT denervation, confirmed by immunocytochemistry, showed tau modulations during the treadmill schedule. Failure to entrain was not explained by group differences in tau before the treadmill schedules. The results indicate that the SCN and both NPY and 5-HT are necessary for entrainment to 24 hr schedules of forced running but that complete loss of 5-HT does not prevent modulations of pacemaker motion by behavioral stimuli. Treadmill entrainment in mice may involve synergistic interactions between 5-HT and NPY afferents at some site within the circadian system.

Animals↗

PubMed1976

A cinematographic analysis of overground and treadmill running by males and females.

Cinematography was used to biomechanically compare individually selected overground jogging and running velocities with equated treadmill jogging and running by adult males and females. All subjects were regular joggers but not competitive track or cross-country runners. No significant differences were recorded in stride length, stride rate, support time or non-support time for males or females when jogging at velocities of between 3.33 and 4.78 m/s (x = 3.70) or 3.45 and 4.80 m/s (x=3.97) respectively. However, it was demonstrated that at velocities of 4.82 - 6.2 m/s for males (x - 5.41) and 4.85 - 5.76 m/s for females (x = 5.29) significant differences did occur between overground and treadmill running. For both males and females stride length decreased, stride rate increased, and the period of non-support was also significantly less when running on a treadmill as compared to running overground.

Adult↗

PubMed1998

The Bruce treadmill protocol: does walking or running during the fourth stage alter oxygen consumption values?

OBJECTIVE: To investigate heart rate (HR) and relative oxygen consumption (VO2) measures during two modes (walking or running stages four) of the Bruce treadmill protocol. PARTICIPANTS: Male volunteers (n = 27), ranging in age from 25 to 56 years (M = 39.1 +/- 10.7 yrs). EXPERIMENTAL DESIGN: S's performed to volitional fatigue on the two randomly assigned treadmill tests. MEASURES: HR and VO2 were taken each minute and at point of exhaustion. RESULTS: Dependent "t"-tests revealed a significantly (p < or = 0.05) difference between the protocols at 11 minutes (running = 46.7 +/- 3.9 > walking = 44.6 +/- 3.7 ml[kg.min-1]) and at 12 minutes (running = 49.3 +/- 4.1 > walking = 47.6 +/- 3.5 ml[kg.min-1]) on the VO2 values. A significant differences was noted on HR at 11 minutes (running = 158.1 +/- 13.5 > walking = 156.0 +/- 13.0 bpm) and at 12 minutes (running = 160.4 +/- 11.0 > walking = 157.8 +/- 11.4 bpm) between the protocols. The two-way ANOVA technique revealed no significant differences or interactions on VO2 or HR between younger (< 45 yrs) and older (> or = 45 yrs) subjects during either protocol. A one-way ANCOVA indicated no significant differences between taller and shorter subjects on VO2 during the fourth stage of the Bruce protocol. The correlations, between the two protocols, for HR were strong but were weaker and inconsistent for VO2. The repeated measures ANOVA indicated significant within subject variability between test administrations. CONCLUSIONS: When testing endurance trained males, modality, age and height are not factors in differences of VO2 values during the 4th stage of the Bruce treadmill test but learning effect could be.

Adult↗

PubMed1998

Relationship of somatotype and physical characteristics to distance running performance in middle age runners.

BACKGROUND: The purpose of this study was to determine the variance explained by somatotype, selected anthropometric variables, and muscle cross-sectional area (CSA) on 10 km run time. METHODS: Subjects were 19 female and 34 male moderately trained distance runners who competed in a local 10 km road race. Mean ages were 39.7 +/- 9.2 for females and 42.7 +/- 10.3 yr for males. RESULTS: Endomorphy explained 41.0% (R = 0.64, SEE = 6.5 min) of the variance in females' 10 km time, whereas body mass index explained 28.0% (R = 0.53, SEE = 7.8 min) with mesomorphy adding 10.4% (R = 0.62, SEE = 7.3 min) more explained variance in males' running times. With data combined for men and women, endomorphy explained 22.1% (R = 0.47, SEE = 7.9 min) of the variance. CONCLUSIONS: It was concluded that somatotype and body mass index explain a moderate portion of the variance in 10 km run performance in runners heterogeneous in ability. Muscle and muscle plus bone cross-sectional area of related running muscles does not contribute to the explained variance in men. Research seeking to explain sources of variation in running performance should consider including somatotype as an independent variable.

Adult↗