Correlations between VO2max and performance times of recreational triathletes.

Twenty-three recreational triathletes, 16 male and 7 female (mean = 21.7 yrs), performed max tethered swim (TS), cycle ergometer (CE), and treadmill run (TR) tests prior to participation in a competitive triathlon (0.91 km swim, 40 km cycle, 10 km run). The VO2max values on the TS, CE and TR were similar to those reported for trained athletes in each sport. As a group, cycling times were significantly correlated to both absolute (p less than 0.01) and relative (p less than 0.001) cycling VO2max (r = -0.57 and r = -0.78, respectively); running times significantly correlated with relative (p less than 0.001, r = -0.84) but not absolute (p greater than 0.05) running VO2max; and swimming times significantly correlated with absolute (p less than 0.01, r = -0.49) but not relative (p greater than 0.05) swimming VO2max. With the exception of absolute swim VO2max, the total performance times were significantly correlated to all VO2max values when expressed in both absolute and relative values. This study indicates the important role a moderately trained individual's aerobic power has in determining performances in endurance events such as the triathlon.     

Ventilatory threshold and VO2max changes in children following endurance training

There are conflicting data with regard to the effect of endurance training in children. On the basis of this information, the effects of 8 wk of run training on ventilatory threshold (VT) and VO2max of eight male children were investigated. Children ranged in age from 10 to 14 yr, with a mean age of 12.4 yr. All subjects were previously untrained. Training consisted of running 4 d.wk-1 for a period of 8 wk. Continuous running was performed 2 d.wk-1 for 10-30 min at 70-80% of VO2max. Interval running was performed the remaining 2 d.wk-1. Repeated intervals of 100-800 m at 90-100% of VO2max were used in this phase of the training. The total distance run for this type of training was 1.5-2.5 km. Incremental treadmill testing prior to and after the training period indicated a 19.4% increase in VT from 30.5 to 36.4 ml.kg-1.min-1 (P less than 0.05). When VT was expressed as a percentage of VO2max, there was a significant (P less than 0.05) increase from 66.6% to 73.8%. VO2max increased 7.5% from 45.9 to 49.4 ml.kg-2.min-2 (P less than 0.05). None of these changes was noted in eight age- and size-matched children who served as control subjects. The results of this study indicate that 8 wk of endurance running training which is of sufficient frequency, intensity, and duration can significantly improve VT and aerobic capacity in male children.     

Maximal aerobic power measurement in runners and swimmers.

Five cross-country runners and five competitive swimmers performed a pulling exercise with elastic shock cords and a treadmill run to exhaustion. The mean VO2 max related to lean body mass of the runners was significantly higher than the swimmers on the treadmill (p less than 0.05) while, on the pulling test, the mean VO2 max of the swimmers was significantly higher than the runners (p less 0.01). The maximum heart rates achieved pulling were 95% of the running maximum by runners and 96% by swimmers with no significant difference between them. Their mean oxygen pulse was almost the same for maximal running but the swimmers had a significantly higher oxygen pulse than the runners for maximal pulling (p less than 0.01). The swimmers could reach about 79% of their running VO2 max by pulling while the runners used 53% of their running VO2 max.     

Determinants of the training response in elderly men

As part of a prospective randomized trial of the effect of regular exercise in older men, factors determining the magnitude of VO2max increase observed with endurance training were examined in 88 elderly [age 62.9 +/- 3.0 (SD) yr] males. VO2max before and after training was recorded as the highest VO2 observed during two incremental treadmill tests. One year of thrice weekly training sessions increased VO2max (12%, P less than 0.05) in the training group relative to baseline and to a control group (n = 100). The association between the post-training VO2max (VO2max, T2) and the following explanatory variables was assessed using multiple regression analysis: the initial VO2max (VO2max, T1); the reason for stopping the initial treadmill test: leisure time activity during the year previous to the study: the training intensity (speed of walking or running, pulse rate during training, and percentage of heart rate reserve); pulmonary function (forced expiratory volume in 1 s); adiposity (skinfold thickness at 8 sites) and frequency of training. VO2max T1, speed of walking or running during training, reason for stopping the treadmill test, and skinfold thickness were significantly related to post-training VO2max. The intensity and frequency of the training stimulus explained over 10% of the variance in the training effect. Subjects whose test was halted because of fatigue increased VO2max more than those whose test was discontinued for medical or other reasons, even when speed of running was held constant. Previous activity had only a weak effect on training response. The total variance explained by these independent variables was 62%.     

Physiological effects of a military training program on male and female cadets.

Tested at the beginning and the end of the 6-week training program which all incoming cadets (plebes) undergo upon entering the U.S. Military Academy were 29 males and 26 females (17-21 years old). The aerobic training consisted of running for 30 min 5-6 d/week at varied speeds depending upon performance in an initial 1.5-mile run test. Females responded to training with a significant increase (p is less than 0.001) in VO2 max from 46.0 +/- 1.0 to 49.7 +/- 0.8 ml/kg.min (7.9%). Males did not increase their initial VO2 max (59.4 +/- 1.1 ml/kg.min) significantly. Both groups significantly reduced HRmax and percent body fat. Their initial VO2 max values and activity history accounted for the lack of a significant increase in this highly-fit population of males. Blood lactates were significantly decreased (p is less than 0.05) at the same two submaximal workloads after training. The initial difference in aerobic power between males and females was reduced from 22% to 18%.     

Effect of short-term training cessation on performance measures in distance runners.

This study examined if measures associated with distance running performance were affected by short-term (14 d) training cessation in 12 distance runners. VO2max decreased by approximately 3 ml.kg-1.min-1 (mean +/- SE, 61.6 +/- 2.0 vs 58.7 +/- 1.8 ml.kg-1.min-1, p < 0.05) with training cessation. Time to exhaustion (TTE) during the incremental VO2max test decreased by 1.2 min (13.0 +/- 0.5 vs 11.8 +/- 0.5 min, p < 0.001) and maximal heart rate increased (p < 0.001) by 9 beats per minute (BPM). No changes in running economy (75 and 90% VO2max) were evident, although submaximal heart rate increased by 11 BPM (p < 0.001) at both running speeds. Other evidence for detraining were decreases in estimated resting plasma volume (-5.1 +/- 1.9%) and muscle citrate synthase activity (-25.3 +/- 2.6%, p < 0.05). Muscular atrophy (muscle fiber cross-sectional area) was not evident. TTE and submaximal heart rate exhibited relatively large percent changes (-9 and +6%, respectively) compared to VO2max (-4%). These findings indicate that the reduction in VO2max with short-term training cessation is relatively small. TTE and submaximal heart rate may be easily measured, yet more sensitive indicators of decrements in distance running performance.     

Effect of water-training in the maintenance of cardiorespiratory endurance of athletes.

The effectiveness of water-training in maintaining cardiorespiratory endurance was investigated in 16 cross country athletes, 18--24 years. Following a competitive season, subjects were stress-tested (T1) and divided into three equated groups based on VO2 max. Group I (n=5) continued training as it had during the competition season. Group II (n=5) underwent an experimental period of water-training, and Group III (n=6) let their training lapse. Subjects in the water-training group exercised in deep water for 40 minutes, 6 days/week for 3 weeks, supported by a flotation device which permitted them to engage in a running type activity, resembling their natural running form. All subjects were retested after 3 weeks (T2). A non-significant F ratio from an analysis of variance at T1 confirmed the equality of the three groups in terms of VO2 max. Analysis of covariance at T2 using T1 VO2 max values as covariates revealed a significant (p less than .05) F ratio reflecting a significant (p less than .05) difference between the regular training group and the group which let its training lapse. The water-training group did not differ significantly from the regular training group indicating that the water-training programme prevented a significant decline in VO2 max.     

Improved insulin sensitivity in carbohydrate and lipid metabolism after physical training

To estimate physical training effects quantitatively, the relationship between tissue sensitivity to exogenous insulin (glucose metabolism determined by euglycemic insulin-clamp technique) and maximal oxygen uptake (VO2 max) was defined in 9 well-trained athletes and 14 untrained subjects with normal glucose tolerance. Tissue sensitivity to exogenous insulin in the athletes was significantly higher than in the controls (P less than 0.001). Seven untrained subjects continued the physical exercise program. After physical training for 1 month, glucose metabolism increased from 40.3 +/- 3.9 mumol/kg/min to 42.2 +/- 4.4 mumol/kg/min (P less than 0.05) and VO2 max also increased significantly (P less than 0.05). During euglycemic hyperinsulinemia, both plasma FFA (P less than 0.001) and glycerol (P less than 0.05) decreased rapidly after physical training. Glucose metabolism directly correlated with VO2 max (P less than 0.001). These results suggest that the euglycemic insulin-clamp technique provides a reliable estimate of training effects, tissue sensitivity to physiologic hyperinsulinemia is 46% higher in trained athletes, and physical training improves insulin sensitivity not only in glucose metabolism but also in lipid metabolism.     

Specificity of run training on VO2 max and heart rate cganges during running and swimming

To further evaluate the specificity of aerobic training, maximum physiologic measures (VO2, VE, HR, and R) and submaximal exercise heart rate were determined in control (N = 8) and experimental (N = 11) subjects prior to and following 10-week interval run training. Experimental subjects significantly increased (P less than 0.01) treadmill VO2 max by 252 ml O2 or 6.3%. This was siginificantly larger (P less than 0.01) than the 87 ml O2 or 2.6% increase (P less than 0.05) observed during swimming. Max HR decreased significantly in both forms of exercise. In addition, heart rate at two submaximal work levels during running and swimming was significantly lower after training.No changes in metabolic and physiologic measures were demonstrated for the controls after the 10-wk period. These results further support the concept of the specificity of the metabolic adaptation to aerobic training and strongly suggest that local adaptations in skeletal muscle significantly contribute to improvement in VO2 max. However, running may produce a general training adaptation in maximal and submaximal heart rate.     

Failure of target heart rate to accurately monitor intensity during aerobic dance

Fourteen untrained females (age 19 +/- 1, range 18-21) were studied to examine the heart rate-VO2 relationship during a single aerobic dance training session. These findings were used to help explain the changes in VO2max resulting from an aerobic dance training program. VO2max and body composition were determined before and after an 8 wk training period. In addition, the heart rate-VO2 responses to an aerobic dance training session were monitored and compared to the heart rate responses of treadmill jogging performed at the same VO2. The aerobic dance session elicited a significantly lower oxygen pulse than did treadmill exercise (7.2 +/- 0.3 vs 8.1 +/- 0.8 ml.beat-1; P less than 0.01). There were no significant changes in percent body fat, whereas VO2max increased by 11% (34.4 +/- 0.9 vs 38.1 +/- 0.8 ml.kg-1.min-1; P less than 0.05). No significant changes in any of the parameters tested were observed in 10 untrained controls. These findings indicate that the heart rate elicited from aerobic dance represents a lower relative exercise intensity (VO2) than that of running. Therefore, the assumption that aerobic dance training produces the same cardiovascular adaptations as running training when performed at the same target rate may be unwarranted.     

Aerobic high-intensity intervals improve VO2max more than moderate training

PURPOSE: The present study compared the effects of aerobic endurance training at different intensities and with different methods matched for total work and frequency. Responses in maximal oxygen uptake (VO2max), stroke volume of the heart (SV), blood volume, lactate threshold (LT), and running economy (CR) were examined. METHODS: Forty healthy, nonsmoking, moderately trained male subjects were randomly assigned to one of four groups:1) long slow distance (70% maximal heart rate; HRmax); 2)lactate threshold (85% HRmax); 3) 15/15 interval running (15 s of running at 90-95% HRmax followed by 15 s of active resting at 70% HRmax); and 4) 4 x 4 min of interval running (4 min of running at 90-95% HRmax followed by 3 min of active resting at 70%HRmax). All four training protocols resulted in similar total oxygen consumption and were performed 3 d.wk for 8 wk. RESULTS: High-intensity aerobic interval training resulted in significantly increased VO2max compared with long slow distance and lactate-threshold training intensities (P<0.01). The percentage increases for the 15/15 and 4 x 4 min groups were 5.5 and 7.2%, respectively, reflecting increases in V O2max from 60.5 to 64.4 mL x kg(-1) x min(-1) and 55.5 to 60.4 mL x kg(-1) x min(-1). SV increased significantly by approximately 10% after interval training (P<0.05). CONCLUSIONS:: High-aerobic intensity endurance interval training is significantly more effective than performing the same total work at either lactate threshold or at 70% HRmax, in improving VO2max. The changes in VO2max correspond with changes in SV, indicating a close link between the two.     

Ventilatory threshold and maximal oxygen uptake during cycling and running in female triathletes

Maximal oxygen uptake (VO2max) and the ventilatory threshold (Tvent) were measured during cycle ergometry (CE) and treadmill running (TR) in a group of 10 highly trained female triathletes. Tvent was defined as the VO2 at which the ventilatory equivalent for oxygen increased without a marked rise in the ventilatory equivalent for carbon dioxide. Female triathletes achieved a significantly higher mean (+/- SE) relative VO2max for running (63.6 +/- 1.2 ml.kg-1.min-1) than for cycling (59.9 +/- 1.3 ml.kg-1.min-1). When oxygen uptake measured at the ventilatory threshold was expressed as a percent of VO2max, the mean value obtained for TR (74.0 +/- 2.0% of VO2max) was significantly greater than the value obtained for CE (62.7 +/- 2.1% of VO2max). This occurred even though the total training time and intensity were similar for the two modes of exercise. Female triathletes had average running and cycling VO2max values that compared favorably with maximal oxygen uptake values previously reported for elite female runners and cyclists, respectively. However, mean running and cycling Tvent values (VO2 Tvent as%VO2max) were lower than recently reported values for single-sport athletes. The physiological variability between the triathletes studied and single-sport athletes may be attributed in part to differences in training distance or intensity, and/or to variations in the number of years of intense training in a specific mode of exercise. It was concluded that these triathletes were well-trained in both running and cycling, but not to the same extent as female athletes who only train and compete in running or cycling.     

Exercise metabolism in runners.

The purpose of this study was to re-examine the commonly accepted association between high maximum oxygen uptake (VO2 max) values and the characteristics of metabolic adaptation to endurance training. The metabolic responses of 9 active males and 8 endurance trained females were observed during one hour of treadmill running at two speeds. One speed was common to both groups (3.58 m s-1. Test 1) whereas the second speed represented approximately 62% VO2 max for each individual (Test 2). The VO2 max values of the males were significantly (p less than 0.01) higher than those of the females but observations of the respiratory exchange ratio and of the changes in the concentrations of metabolites were indicative of greater fat metabolism in the well-trained female group in both Tests. Thus the results of this study suggest that the benefits of endurance training are independent of the absolute values of VO2 max.     

Manipulating high-intensity interval training: effects on VO2max, the lactate threshold and 3000 m running performance in moderately trained males.

The aim of this study was to compare the effects of two high-intensity interval training (HIT) programmes on maximal oxygen uptake (.VO(2max)), the lactate threshold (LT) and 3000 m running performance in moderately trained male runners. .VO(2max), the running speed associated with .VO(2max) (V.VO(2max)), the time for which V.VO(2max) can be maintained (T(max)), the running speed at LT (v(LT)) and 3000 m running time (3000 mTT) were determined before and following three different training programmes performed for 10 weeks. Following the pre-test, 17 moderately trained male runners (V O(2max)=51.6+/-2.7ml kg(-1)min(-1)) were divided into training groups based on their 3000 mTT (Group 1, G(1), N=6, 8 x 60% of T(max) at V.VO(2max), 1:1 work:recovery ratio; Group 2, G(2), N=6, 12 x 30s at 130% V.VO(2max), 4.5 min recovery; control group, G(CON), N=5, 60 min at 75% V.VO(2max)). G(1) and G(2) performed two HIT sessions and two 60 min recovery run sessions (75% V.VO(2max)) each week. Control subjects performed four 60 min recovery run sessions (75% V.VO(2max)) each week. In G(1), significant improvements (p<0.05) following HIT were found in .VO(2max) (+9.1%), V.VO(2max) (+6.4%), T(max) (5%), v(LT) (+11.7%) and 3000 mTT (-7.3%). In G(2), significant improvements (p<0.05) following HIT were found in .VO(2max) (+6.2%), V.VO(2max)(+7.8%), T(max) (+32%) and 3000 mTT (-3.4%), but not in v(LT) (+4.7%; p=0.07). No significant changes in these variables were found in G(CON). The present study has shown that 3000 m running performance, .VO(2max), V.VO(2max), T(max) and v(LT) can be significantly enhanced using different HIT programmes in moderately trained runners, but that changes in performance and physiological variables may be more profound using prolonged HIT at intensities of V.VO(2max) with interval durations of 60% T(max).     

Effects of 7 successive days of unaccustomed prolonged exercise on aerobic performance and tissue damage in fitness joggers

The effects of 7 successive days of prolonged jogging on aerobic performance and biochemical markers of muscle and red blood cell damage were examined in 10 moderately fit men, ages 27 +/- 2 yr (mean +/- SE). The subjects jogged for 2 h per day at 78 +/- 4% of maximal heart rates and covered a total of 129 +/- 2 km, nearly eight times their regular weekly training distance. At baseline, maximal oxygen uptake (VO2max) during treadmill tests averaged 3.45 +/- 0.24 L/min, or 44.7 +/- 1.4 ml/kg/min. On follow-up tests 2d after the week of increased training, VO2max (3.56 +/- 0.17 L/min) and treadmill performance were not significantly improved. Body weight declined from 79.5 +/- 4.6 kg to 77.8 +/- 4.4 kg (p less than 0.05) because of reduced body fatness (16.8 +/- 2.3% to 13.6 +/- 1.7%, p less than 0.05). Weight-adjusted VO2max increased to 46.4 +/- 2.0 ml/kg/min (p less than 0.05). However, heart rate and systolic blood pressure were not significantly changed at rest, or during submaximal and maximal treadmill exercise. Mean hemoglobin concentration at treadmill testing declined from 14.9 +/- 0.3 g/dl to 13.3 +/- 0.3 g/dl (p less than 0.05). Leg muscle soreness, especially in the thigh region, persisted in all subjects after 3 d. Soreness was accompanied by chronic elevations (p less than 0.05) in serum levels of myoglobin, creatine kinase (CK), lactic dehydrogenase (LD), aminoaspartate, and the isoenzymes CK-MB and LD1,2. Serum haptoglobin levels after jogging fell from 86 +/- 9 mg/dl to 60 +/- 8 mg/dl (p less than 0.05), suggestive of footstrike hemolysis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Resistive training can reduce coronary risk factors without altering VO2max or percent body fat

Eleven healthy, untrained males (age = 44 +/- 1 yr; range = 40 to 55 yr) were studied to determine the effects of 16 wk of high-intensity resistive training on risk factors for coronary artery disease. Lipoprotein-lipid profiles, plasma glucose and insulin responses during an oral glucose tolerance test, and blood pressure at rest were determined before and after training. The training program resulted in a 13% increase in high-density lipoprotein-cholesterol (39 +/- 2 vs 44 +/- 3 mg.dl-1, P less than 0.05), a 43% increase in high-density lipoprotein-cholesterol (7 +/- 2 vs 10 +/- 2 mg.dl-1, P less than 0.05), a 5% reduction in low-density lipoprotein cholesterol (129 +/- 5 vs 122 +/- 5 mg.dl-1, P less than 0.05), and an 8% decrease in the total cholesterol/high-density lipoprotein-cholesterol ratio (5.1 +/- 0.3 vs 4.7 +/- 0.3, P less than 0.01), despite no changes in VO2max, body weight, or percent body fat. Glucose-stimulated plasma insulin concentrations during oral glucose tolerance testing were significantly lower, and supine diastolic blood pressure was reduced (P less than 0.05) as a result of the training program. No changes in any of these variables occurred in a sedentary control group. These findings indicate that resistive training can lower risk factors for coronary artery disease independent of changes in VO2max, body weight, or body composition.     

Reduced training maintains performance in distance runners

This investigation examined endurance runners during a 3-week reduction in training volume and frequency. Ten well-conditioned runners were monitored for 4 weeks while training at their normal weekly training distance (mean +/- SE) (81 +/- 5 km/week, 6 days/week). This period was designated as baseline training (BT). Sixty km/week were run at approximately 75% VO2max, and the remainder (21 km/week) at approximately 95% VO2max in the form of intervals and races. The runners then reduced weekly training volume (RT) by 70% of BT to 24 +/- 2 km/week and frequency by 17% to 5 days/week for 3 weeks. During RT 17 km/week was performed at approximately 75% VO2max and the remainder (7 km/week) at approximately 95% VO2max (intervals and races). The runners were tested weekly and performed 5-km races on a 200-m indoor track during Bt and after 2 and 3 weeks of RT. Maximal heart rate (HR) increased (P less than 0.05) by approximately 4 beats/min at RT week 3, which may have been associated with a decrease in estimated plasma volume (P less than 0.01) of 5.62 +/- 0.43%. Time to exhaustion during the VO2max tests increased (P less than 0.05) by 9.5% at RT week 3. No significant (P greater than 0.05) changes occurred with RT in body weight, % body fat, overall 5 km race times, VO2max, muscular power (vertical leap and Margaria power test), and citrate synthase activity (at 2 weeks of RT). No alterations in venous lactate, energy expenditure, and HR were observed during submaximal running at two speeds (approximately 65% and 85% VO2max) with RT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of marathon training on the plasma lactate response to submaximal exercise in middle-aged men.

Twenty-one previously sedentary male volunteers (aged 35-50 years) undertook a defined marathon training programme lasting 30 weeks. At weeks 0 (T1), 15 (T2) and 30 (T3) they underwent measurement of maximal oxygen uptake (VO2 max), submaximal VO2 and submaximal plasma lactate concentration during cycle ergometry. No exercise was taken for 24-48 hours prior to testing. During training aerobic power increased significantly (p less than 0.001) from an initial VO2 max at T1 of 33.9 +/- 6 (mean +/- sd) ml.kg-1min-1 to 39 +/- 5.6 ml.kg-1min-1 at T2 but the T3 value of 39.2 +/- 5.2 ml.kg-1min-1 was not significantly different from that at T2. Plasma lactate concentration of 4 mmol.l-1 (OBLAw) occurred at a significantly (P less than 0.05) higher workload (155 +/- 28 w) at T2 compared with T1 (132 +/- 30 w) but the T3 figure was 137 +/- 34 w. OBLA VO2 at T1 was 2.04 +/- 0.42 l.min-1, at T2 was 2.24 +/- 0.04 l.min-1 but at T3 was 2.03 +/- 0.30 l.min-1 (T1:T2 P less than 0.05, T1:T3 NS). OBLA % VO2 max at T1 was 75 +/- 12%, at T2 was 73 +/- 11% but at T3 was 62 +/- 10% (T1:T2 NS, T1:T3 P less than 0.01).     

Longitudinal assessment of responses by triathletes to swimming, cycling, and running

Fourteen triathletes (eight male, six female) were tested four times (in February, May, August, and October) to monitor adaptations to training for a triathlon (1.9-km swim, 90.3-km bike, 21.1-km run). VO2max was measured during treadmill running (TR), cycle ergometry (CE), and tethered swimming (TS). Lactate threshold (LT), defined as the VO2 at a lactate concentration of 4 mM, was determined during TR and CE. In all sessions, TS VO2max was less than TR and CE (P less than 0.05), and CE was less than TR (P less than 0.05). Means for Session I were 57.4, 53.4, and 48.3 ml.min-1.kg-1 for TR, CE, and TS, respectively. Corresponding values for Session IV were 58.4, 56.0, and 47.8 ml.min-1.kg-1. The only significant increase in VO2max was for CE (5%). VO2 at the LT increased from Session I to IV for both TR (6%) and CE (10%); the LT for TR was at a higher VO2 than for CE in all sessions. The percent VO2max at LT for TR in Sessions I and IV was 80 and 85%, respectively. Analogous values for CE were 72 and 76%. The minimal increases in VO2max suggest that subjects had reached their potential in this parameter. Improvements in race performance were probably attained through peripheral adaptations, as suggested by increases in the VO2 at LT. The occurrence of the LT at a lower percent VO2max in cycling than in running suggests that the triathletes had greater potential for improvement in cycling.     

Effects of concurrent endurance and strength training on running economy and .VO(2) kinetics

PURPOSE: It has been suggested that endurance training influences the running economy (CR) and the oxygen uptake (.VO(2)) kinetics in heavy exercise by accelerating the primary phase and attenuating the .VO(2) slow component. However, the effects of heavy weight training (HWT) in combination with endurance training remain unclear. The purpose of this study was to examine the influence of a concurrent HWT+endurance training on CR and the .VO(2) kinetics in endurance athletes. METHODS: Fifteen triathletes were assigned to endurance+strength (ES) or endurance-only (E) training for 14 wk. The training program was similar, except ES performed two HWT sessions a week. Before and after the training period, the subjects performed 1) an incremental field running test for determination of .VO(2max) and the velocity associated (V(.VO2max)), the second ventilatory threshold (VT(2)); 2) a 3000-m run at constant velocity, calculated to require 25% of the difference between .VO(2max) and VT(2), to determine CR and the characteristics of the VO(2) kinetics; 3) maximal hopping tests to determine maximal mechanical power and lower-limb stiffness; 4) maximal concentric lower-limb strength measurements. RESULTS: After the training period, maximal strength were increased (P < 0.01) in ES but remained unchanged in E. Hopping power decreased in E (P < 0.05). After training, economy (P < 0.05) and hopping power (P < 0.001) were greater in ES than in E. .VO(2max), leg hopping stiffness and the .VO(2) kinetics were not significantly affected by training either in ES or E. CONCLUSION: Additional HWT led to improved maximal strength and running economy with no significant effects on the .VO(2) kinetics pattern in heavy exercise.