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PubMed1990

Effects of a prolonged maximal run on running economy and running mechanics.

The purpose of this study was to document the effects of a prolonged (30 min) maximal run (PMR) on running economy (RE) and running mechanics in 16 male runners (mean VO2max = 59.0 +/- 4.5 ml.kg-1.min-1). After completing 60 min of treadmill accommodation, each subject performed two 10 min economy runs at 200 m.min-1. Subjects were also filmed at 100 fps during the last 30 s of each run in order to quantify 20 temporal, kinematic, and kinetic gait descriptors previously associated with RE variation. Following the second run, each subject completed the PMR at 85% of his predicted velocity at VO2max (89% VO2max). One, two, and four days after the PMR, subjects repeated the 10 min economy run. No significant difference (P greater than or equal to 0.05) in RE (range = 42.3-42.6 ml.kg-1.min-1) was observed following the PMR. Biomechanical analyses also indicated that, with the exception of one variable (plantar flexion angle at toe-off), gait characteristics remained unaltered after the PMR. When considered from a cross-disciplinary perspective, these data suggest that a 30 min maximal run does not increase the aerobic demand of running or disrupt the running mechanics of moderately trained male subjects who perform subsequent submaximal runs over the short term.

Adult↗

PubMed1995

Run training vs cross training: influence of increased training on running economy, foot impact shock and run performance.

The purpose of the study was to compare changes in running economy, foot impact shock, run performance, and resting heart rate and blood pressure elicited by increases in training volume via run training (RT) and cross training (CT). After 30 d of normal training (NT), male runners (N = 11) completed two 10 d periods of increased training each preceded by 14 d of reduced training (80% NT). Subjects ran 10 consecutive days in the afternoon (100% of NT) and performed 8 additional workouts in the morning (100% of NT). The morning sessions were performed on a cycle ergometer (CT) or a treadmill (RT). Running economy, foot impact shock and lactate were assessed during submaximal running (3.9 +/- 0.06 m.sec-1) at D0 and D11. Following the submaximal run, subjects completed a simulated 5 km race on a treadmill. VO2 during the running economy test was significantly higher at D11 of CT (52.5 +/- 1.5) compared to RT (51.1 +/- 1.4 ml.kg-1.min-1). RER, carbohydrate oxidation, and lactate were significantly lower; whereas, foot impact shock was significantly higher following both training modes. No significant changes in run performance, resting heart rate and blood pressure occurred during the study. In summary, 10 d of increased training resulted in a reduced running economy for CT, and a lower carbohydrate oxidation and an increase in foot impact shock for both training modes.

Adult↗

PubMed1999

Can the Transition To and From Running and the Metabolic Cost of Running Be Determined From the Kinetic Energy of Running?

An experiment was conducted in which volume of used oxygen per stride time and the total segmental changes in kinetic energy generated per stride time, &grD;E(k)>s(-1), of 11 participants were determined on Day 1 for 7 treadmill running speeds. Gait transition speeds were determined on Day 2. Running metabolism and transition speed were predicted from the Day 1 mechanics of running expressed in Speed x &grD;E(k)>s(-1) coordinates. Predictions followed from the relation between 2 generalized quality ratios Q(metab), and Q(mech), with numerator &grD;E(k)>s(-1). In Q(metab), the denominator was the volume of used oxygen per stride time; in Q(mech), the denominator was the absolute regression constant from the linear dependency of &grD;E(k)>s(-1) on speed.

Journal Article↗

PubMed1996

Tests of running performance do not predict subsequent spontaneous running in rats.

Rats of similar mass and genetic stock have up to a 50-fold difference in spontaneous daily running distance. However, the reasons for this large variability in spontaneous running distance are not known. This study examined whether tests of running performance predict subsequent spontaneous running distance in rats housed in individual running wheel cages. Long-Evans rats (n = 56) were randomly assigned to either a sedentary control group (C) or a group housed in specially designed wheel cages in which they were able to exercise spontaneously (ES). They then underwent a high-intensity running test (MAX), during which oxygen consumption was measured at a submaximal (VO2 submax) and maximal workload (VO2 max). The rats' submaximal running endurance (END) and maximal sprinting speed (SPRINT) were also tested on the treadmill. After 8 weeks the average spontaneous running distance of ES was 29.7 +/- 3.7 km.wk-1 (mean +/- SE), but ranged from 1.4 to 71.1 km.wk-1. Tests of running performance and oxygen consumption were repeated in both groups, followed by in situ measurements of muscle contractile properties and of citrate synthase activity in the skeletal muscle. None of the measurements of running performance or oxygen consumption during the initial tests conducted at the start of the experiment was related to subsequent average spontaneous running distance. After 8 weeks, the mean peak force generated by the electrically stimulated gastrocnemius/plantaris muscles was greater in ES than in C (746 +/- 89 vs. 455 +/- 28 mg, p < 0.005), but this difference was not related to spontaneous running distance. Conversely, citrate synthase activity of the soleus muscle after training was related to average spontaneous running distance (r = 0.92, p < 0.0004). Average spontaneous running distance was also related to MAX (r = 0.65, p < 0.002), END (r = 0.59, p < 0.0009), and SPRINT (r = 0.61, p < 0.0005) and was inversely related to running intensity (r = -0.66, p < 0.002) after 8 weeks of training. It can be concluded from this study that 1) spontaneous running distance in rats cannot be predicted by pretraining tests of running performance. Hence, low levels of spontaneous running activity in some rats are not explained by skeletal muscular and cardiovascular factors thought to determine running capacity, and 2) posttraining tests of running performance were proportionally related to total spontaneous running distance and muscle oxidative enzyme changes but not to the in situ contractile properties of the muscles.

Animals↗

PubMed1998

Development of osteoarthritis in the knee joints of Wistar rats after strenuous running exercise in a running wheel by intracranial self-stimulation.

The influence of excessive running load on the development of knee osteoarthritis (OA) was investigated in male Wistar rats. Running exercises were performed in a running wheel using intracranial self-stimulation to motivate Wistar rats to run daily distances of 500 m at 5 days/week. Hereby, ten rats ran a distance of 15 km within three weeks while a further ten rats run a total of 30 km within six weeks. Thirteen Wistar rats without running exercises served as controls. Complete knee joint sections of all rats were evaluated histologically using MANKINs grading system with categorization of the findings into non, mild moderate, and severe osteoarthritis. In addition, immunoreactivity of the chondrocytes to MMP-3 as an important cartilage degrading enzyme in OA was assessed by immunostaining with monoclonal MMP-3 IgG antibodies. Histological assessment of the knee joint sections revealed a significant increase in osteoarthritic changes with higher running load. While in rats with 15 km running all but two knee joints showed mild OA, moderate OA was the predominant finding in rats with 30 km running. In contrast, no OA was found in the controls. Immunostaining for MMP-3 revealed a significant increase in immunoreactivity of the chondrocytes to MMP-3 with higher running load, indicating a running load-depending production of this cartilage-degrading enzyme in the course of increasing OA. Compared to 47.4% immunoreactive chondrocytes to MMP-3 in the controls, this ratio rose to 70.4% in rats with 15 km running and even up to 89.9% in rats with 30 km running. In conclusion, in Wistar rats, excessive running load leads to marked, running distance-depending osteoarthritic changes which are caused, at least in part, by an increase in MMP-3 production rising with greater running distance. Within this exercise model of OA, intracranial self-stimulation is an effective method to motivate Wistar rats to extremely excessive running in a running wheel. This model offers a wide range of further approaches to studying different processes of the development of OA.

Animals↗

PubMed2004

Differential regulation of hippocampal progenitor proliferation by opioid receptor antagonists in running and non-running spontaneously hypertensive rats.

Voluntary running in mice and forced treadmill running in rats have been shown to increase the amount of proliferating cells in the hippocampus. Little is known as yet about the mechanisms involved in these processes. It is well known that the endogenous opioid system is affected during running and other forms of physical exercise. In this study, we evaluated the involvement of the endogenous opioids in the regulation of hippocampal proliferation in non-running and voluntary running rats. Nine days of wheel running was compared with non-running in spontaneously hypertensive rats (SHR), a rat strain known to run voluntarily. On the last 2 days of the experimental period all rats received two daily injections of the opioid receptor antagonists naltrexone or naltrindole together with injections of bromodeoxyuridine to label dividing cells. Brain sections from the running rats showed approximately a five-fold increase in newly generated cells in the hippocampus, and this increase was partly reduced by naltrexone but not by naltrindole. By contrast, both naltrexone and naltrindole increased hippocampal proliferation in non-running rats. In non-running rats the administration of naltrexone decreased corticosterone levels and adrenal gland weights, whereas no significant effects on these parameters could be detected for naltrindole. However, adrenal gland weights were increased in naltrexone- but not in naltrindole-administered running rats. In addition, in voluntary running rats there was a three-fold increase in the hippocampal levels of Met-enkephalin-Arg-Phe compared with non-runners, indicating an increase in opioid activity in the hippocampus during running. These data suggest an involvement of endogenous opioids in the regulation of hippocampal proliferation in non-running rats, probably through hypothalamic-pituitary-adrenal axis modulation. During voluntary running in SHR naltrexone altered hippocampal proliferation via as yet unknown mechanisms.

Adrenocorticotropic Hormone↗

PubMed1989

Variations in running activity and enzymatic adaptations in voluntary running rats.

The running behavior and biochemical markers of oxidative and glycolytic activities associated with voluntary running activity were studied in male Sprague-Dawley rats after 6 wk of training in exercise wheel cages. Twenty-four-hour recordings of running activity were used to quantify the number of individual running bouts, their duration and running speed, and the distance run per day. We then established three categories of voluntary running activity based on the mean distance run per day during the last 3 wk of training: low-activity runners averaged 2-5 km/day, medium runners 6-9 km/day, and high runners greater than 11 km/day. Each group demonstrated an intermittent, nocturnal running pattern, at relatively high intensities, with a similar mean running speed for all groups (avg approximately 45 m/min). Differences in total distance run per day were the result of variations in both the number and duration of individual running bouts. Specifically, high runners (n = 7) had 206 +/- 30 individual running bouts per 24 h, each lasting 87 +/- 7 s; medium runners (n = 7) 221 +/- 22 running bouts, lasting 47 +/- 5 s; and low runners (n = 7) 113 +/- 7 bouts, each lasting 40 +/- 7 s. Voluntary running depressed the rate of body weight gain compared with sedentary control rats, despite an increased food and water intake for all runners. Furthermore, drinking activity was temporally associated with running periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1980

Distance running performance and metabolic responses to running in men and women with excess weight experimentally equated.

Metabolic responses to submaximal and maximal treadmill (TM) running and 12-min run performance were measured in 10 female and 10 male adults who regularly engaged in distance running to experimentally investigate the extent to which differences between men and women in metabolic responses to exercise and distance running performance are due to the sex difference in % body fat. The males were studied under two conditions: (1) with normal body weight and (2) with external weight added to the trunk so that the total percent excess weight (% EW) was equal to the % fat of a matched female. Under the added-weight condition, % EW of the males was increased by an average of 7.5%, the mean sex difference in % fat. Equating % EW reduced the mean sex difference in TM run time by 1.3 min (32%) and 12-min run performance by 173 m (30%). These changes in running performance were the result of an average 3.0 ml/min.kg (38%) reduction in the sex difference for the oxygen required per unit fat-free weight (FFW) to run at various submaximal speeds and a 3.9 ml . min-1 . kg-1 (65%) reduction in the sex difference for VO2max expressed relative to the total weight carried. It was concluded that the greater sex-specific, essential body fat of women is one determinant of the sex difference in metabolic responses to running and distance running performance. Because of her greater body fatness, the average woman will utilize more oxygen per unit FFW to run at any given submaximal speed, will have a lower VO2max expressed relative to body weight and, as a result, will maintain a speed on the 12-min run or other similar distance running event which is slower than her male counterpart. Since the sex-specific, essential fat of women cannot be eliminated by diet or training, it provides part of a biological justification for separate distance running performance standards and expectations for men and women.

Adipose Tissue↗

PubMed2005

Responding for sucrose and wheel-running reinforcement: effect of pre-running.

Six male albino Wistar rats were placed in running wheels and exposed to a fixed interval 30-s schedule that produced either a drop of 15% sucrose solution or the opportunity to run for 15s as reinforcing consequences for lever pressing. Each reinforcer type was signaled by a different stimulus. To assess the effect of pre-running, animals were allowed to run for 1h prior to a session of responding for sucrose and running. Results showed that, after pre-running, response rates in the later segments of the 30-s schedule decreased in the presence of a wheel-running stimulus and increased in the presence of a sucrose stimulus. Wheel-running rates were not affected. Analysis of mean post-reinforcement pauses (PRP) broken down by transitions between successive reinforcers revealed that pre-running lengthened pausing in the presence of the stimulus signaling wheel running and shortened pauses in the presence of the stimulus signaling sucrose. No effect was observed on local response rates. Changes in pausing in the presence of stimuli signaling the two reinforcers were consistent with a decrease in the reinforcing efficacy of wheel running and an increase in the reinforcing efficacy of sucrose. Pre-running decreased motivation to respond for running, but increased motivation to work for food.

Animals↗

PubMed2005

Effects of size, sex, and voluntary running speeds on costs of locomotion in lines of laboratory mice selectively bred for high wheel-running activity.

Selective breeding for over 35 generations has led to four replicate (S) lines of laboratory house mice (Mus domesticus) that run voluntarily on wheels about 170% more than four random-bred control (C) lines. We tested whether S lines have evolved higher running performance by increasing running economy (i.e., decreasing energy spent per unit of distance) as a correlated response to selection, using a recently developed method that allows for nearly continuous measurements of oxygen consumption (VO2) and running speed in freely behaving animals. We estimated slope (incremental cost of transport [COT]) and intercept for regressions of power (the dependent variable, VO2/min) on speed for 49 males and 47 females, as well as their maximum VO2 and speeds during wheel running, under conditions mimicking those that these lines face during the selection protocol. For comparison, we also measured COT and maximum aerobic capacity (VO2max) during forced exercise on a motorized treadmill. As in previous studies, the increased wheel running of S lines was mainly attributable to increased average speed, with males also showing a tendency for increased time spent running. On a whole-animal basis, combined analysis of males and females indicated that COT during voluntary wheel running was significantly lower in the S lines (one-tailed P=0.015). However, mice from S lines are significantly smaller and attain higher maximum speeds on the wheels; with either body mass or maximum speed (or both) entered as a covariate, the statistical significance of the difference in COT is lost (one-tailed P> or =0.2). Thus, both body size and behavior are key components of the reduction in COT. Several statistically significant sex differences were observed, including lower COT and higher resting metabolic rate in females. In addition, maximum voluntary running speeds were negatively correlated with COT in females but not in males. Moreover, males (but not females) from the S lines exhibited significantly higher treadmill VO2max as compared to those from C lines. The sex-specific responses to selection may in part be consequences of sex differences in body mass and running style. Our results highlight how differences in size and running speed can account for lower COT in S lines and suggest that lower COT may have coadapted in response to selection for higher running distances in these lines.

Animals↗

PubMed2003

A prospective study of running injuries: the Vancouver Sun Run "In Training" clinics.

OBJECTIVES: Seventeen running training clinics were investigated to determine the number of injuries that occur in a running programme designed to minimise the injury rate for athletes training for a 10 km race. The relative contributions of factors associated with injury were also reported. METHODS: A total of 844 primarily recreational runners were surveyed in three trials on the 4th, 8th, and 12th week of the 13 week programme of the "In Training" running clinics. Participants were classified as injured if they experienced at least a grade 1 injury-that is, pain only after running. Logistic regression modelling and odds ratio calculation were performed for each sex using the following predictor variables: age, body mass index (BMI), previous aerobic activity, running frequency, predominant running surface, arch height, running shoe age, and concurrent cross training. RESULTS: Age played an important part in injury in women: being over 50 years old was a risk factor for overall injury, and being less than 31 years was protective against new injury. Running only one day a week showed a non-significant trend for injury risk in men and was a significant risk factor in women and overall injury. A BMI of > 26 kg/m(2) was reported as protective for men. Running shoe age also significantly contributed to the injury model. Half of the participants who reported an injury had had a previous injury; 42% of these reported that they were not completely rehabilitated on starting the 13 week training programme. An injury rate of 29.5% was recorded across all training clinics surveyed. The knee was the most commonly injured site. CONCLUSIONS: Although age, BMI, running frequency (days a week), and running shoe age were associated with injury, these results do not take into account an adequate measure of exposure time to injury, running experience, or previous injury and should thus be viewed accordingly. In addition, the reason for the discrepancy in injury rate between these 17 clinics requires further study.

Adult↗

PubMedDate not supplied

Effect of water running and cycling on maximum oxygen consumption and 2-mile run performance.

This study compared water running, cycling, and running for maintaining VO2max and 2-mile run performance over a 6-week training period. Thirty-two trained subjects between the ages of 18 and 26 were evaluated for maximum oxygen uptake (VO2max) and 2-mile run performance. Subjects were stratified by a 2-mile run pretest into high, medium, and low performance levels and then randomly assigned to water running, cycling, or running training. The three groups trained with similar frequency, duration, and intensity overa 6-week period. After 6 weeks of training, all of the groups made a small but statistically significant decrease in fitness (VO2max), but no change in 2-mile run time. However, there were no differences with respect to either training modality or pretraining performance level. It was concluded that over a 6-week period, runners who cannot run because of soft tissue injury can maintain VO2max and 2-mile run performance similar to running training with either cycling or water running.

Adolescent↗

PubMed2001

Physiological demands of running during long distance runs and triathlons.

The aim of this review article is to identify the main metabolic factors which have an influence on the energy cost of running (Cr) during prolonged exercise runs and triathlons. This article proposes a physiological comparison of these 2 exercises and the relationship between running economy and performance. Many terms are used as the equivalent of 'running economy' such as 'oxygen cost', 'metabolic cost', 'energy cost of running', and 'oxygen consumption'. It has been suggested that these expressions may be defined by the rate of oxygen uptake (VO2) at a steady state (i.e. between 60 to 90% of maximal VO2) at a submaximal running speed. Endurance events such as triathlon or marathon running are known to modify biological constants of athletes and should have an influence on their running efficiency. The Cr appears to contribute to the variation found in distance running performance among runners of homogeneous level. This has been shown to be important in sports performance, especially in events like long distance running. In addition, many factors are known or hypothesised to influence Cr such as environmental conditions, participant specificity, and metabolic modifications (e.g. training status, fatigue). The decrease in running economy during a triathlon and/or a marathon could be largely linked to physiological factors such as the enhancement of core temperature and a lack of fluid balance. Moreover, the increase in circulating free fatty acids and glycerol at the end of these long exercise durations bear witness to the decrease in Cr values. The combination of these factors alters the Cr during exercise and hence could modify the athlete's performance in triathlons or a prolonged run.

Anemia↗

PubMed1976

[Effect of run-training and run-stress on glucose assimilation and insulin release in rats of different age (author's transl)].

82 male rats of different age have been investigated after a definitive run-training, after a run-training with subsequent run-stress and after a run-stress without run-training. An intravenous glucose tolerance test has been done measuring glucose and insulin serum levels before and after i.v. glucose application. Data obtained in this study demonstrate that: 1. adult rats have a better glucose assimilation and higher insulin serum levels after i.v. glucose than older ones. 2. run-stress leads to a deterioration of glucose assimilation and diminution of insulin release in rats of any age. 3. run-training improves glucose tolerance and saves insulin at the same time. 4. in old rats, which have never done any training before, run-training improves glucose assimilation, too. 5. run-stress after run-training has a different effect on adult and old rats: In adult rats there is nearly no effect on glucose assimilation and insulin release in comparison to control animals, while old rats show a significant deterioration of glucose assimilation in comparison to control rats of the same age. Obviously the effect of run-training is less distinct in old rats despite of similar running work.

Aging↗

PubMed1997

Relationships between running mechanics and energy cost of running at the end of a triathlon and a marathon.

The purpose of the present study was to check the increase in energy cost of running at the end of a triathlon and a marathon and to link the decrease in energy cost of running with running kinematic parameters. Seven well-trained triathletes performed 3 experimental trials: a 2 h 15 min triathlon (30 min swimming, 60 min cycling and 45 min treadmill running), a 2 h 15 min marathon where the last 45 min (MR) were run at the same speed as the triathlon run (TR) (i.e. 75% of maximal aerobic speed), and a 45 min isolated run (IR) done at the same speed. Oxygen uptake (VO2), minute ventilation (VE), heart rate (HR), respiratory exchange ratio (RER) and kinematic data were recorded during the 3 exercise runs. The results confirm a higher energy cost during MR compared with TR (+ 3.2%; p <0.05) and IR (+ 11.7%; p <0.01). The triathlon and the marathon were associated with greater weight loss (1.6 +/- 0.02 kg; p <0.01) than the isolated run (0.7 +/- 0.2 kg). After cycling, the mean stride length in TR1 was lower during IR1 and increased at the end of TR. The results show that MR led to decrease in stride length compared with IR. After cycling, the triathletes adopted a more forward leaning posture and the trunk gradient was less marked during the marathon. Moreover, the extension of the knee at foot-strike and the maximal knee angle in non-support phase both increased during MR compared with TR and IR. However, it appears that no single kinematic variable can fully explain the decrease in running efficiency: it seems that running economy during a triathlon and a marathon are linked to global alterations of many different parameters.

Adult↗

PubMed2007

Changes in running economy following downhill running.

In this study, we examined the time course of changes in running economy following a 30-min downhill (-15%) run at 70% peak aerobic power (VO2peak). Ten young men performed level running at 65, 75, and 85% VO2peak (5 min for each intensity) before, immediately after, and 1 - 5 days after the downhill run, at which times oxygen consumption (VO2), minute ventilation, the respiratory exchange ratio (RER), heart rate, ratings of perceived exertion (RPE), and blood lactate concentration were measured. Stride length, stride frequency, and range of motion of the ankle, knee, and hip joints during the level runs were analysed using high-speed (120-Hz) video images. Downhill running induced reductions (7 - 21%, P < 0.05) in maximal isometric strength of the knee extensors, three- to six-fold increases in plasma creatine kinase activity and myoglobin concentration, and muscle soreness for 4 days after the downhill run. Oxygen consumption increased (4 - 7%, P < 0.05) immediately to 3 days after downhill running. There were also increases (P < 0.05) in heart rate, minute ventilation, RER, RPE, blood lactate concentration, and stride frequency, as well as reductions in stride length and range of motion of the ankle and knee. The results suggest that changes in running form and compromised muscle function due to muscle damage contribute to the reduction in running economy for 3 days after downhill running.

Adult↗

PubMed1989

Effects of a verbal and visual feedback system on running technique, perceived exertion and running economy in female novice runners.

The purpose of this study was to determine the effects of a verbal and visual feedback system on running technique, ratings of perceived exertion (RPE), and running economy. Twenty-two female novice runners were randomly assigned to experimental (n = 11) and control (n = 11) groups. The experimental subjects received verbal and visual feedback concerning their running technique prior to and during each training run. Training involved 15 20-min treadmill running sessions over a 5-week period. The control group adhered to the same training routine but did not receive feedback concerning their running technique. High-speed (100 Hz) photography was used to collect biomechanical data. A submaximal oxygen consumption test and Borg's RPE scale were used to collect data concerning running economy and perceived exertion, respectively. Statistical analysis using ANCOVA revealed that the proposed feedback system had a significant (P less than 0.01) effect on the experimental group's running technique by affecting the following desired changes relative to the control group: greater relative stride lengths, shorter support time, greater ankle dorsiflexion during support and greater knee flexion during support and non-support. There were no significant differences between the groups in submaximal VO2 or RPE. The results of this study suggest that verbal and visual feedback are effective means of eliciting modifications in running style in female novice runners. The link between modifications in running style and improvements in running economy and perceived exertion remains unclear.

Adolescent↗

PubMed1991

Peak running velocity, submaximal energy expenditure, VO2max, and 8 km distance running performance.

The purposes of this study were to examine (1) if the peak running velocity achieved during maximal treadmill testing is related to 8 km distance running performance (DRP) and (2) if the relationship between selected physiological determinants are consistant for two 8 km races within a competitive season. Seven members of a University cross-country team (mean +/- SE) (age, 19.4 +/- 0.5 years, VO2max 67.0 +/- 1.0 ml/kg/min were tested 2-3 days following a mid-season race (Race M) and the season-ending conference championship (Race C). Despite similar weather and terrain, Race C (29:22 +/- 1:22 min:sec) was significantly (p less than 0.05) slower than Race M (28:31 +/- 0:58 min:sec). However, no significant differences (p greater than 0.05) were observed between testing sessions for calculated energy expenditure heart rate oxygen consumption and RER during submaximal running (248 and 268 m/min), postsubmaximal run lactate, peak running velocity, and VO2max. A significant correlation (p less than 0.05) was observed for Race M with with calculated energy expenditure during submaximal running at both speeds (r = 0.85) and with peak running velocity (r = -0.76). Regression analysis revealed that 92% of the total variance for Race M was accounted for by calculated energy expenditure during submaximal running and VO2max. No significant correlation or regression relationship was observed for any variables with Race C. These results suggest that peak running velocity, calculated energy expenditure during submaximal running, and VO2max can be associated with 8 km running performance. However, the relationship between 8 km DRP and the variables measured can differ for two races over a competitive season.

Adult↗