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Showing papers on "Interval training published in 1998"


Journal ArticleDOI
TL;DR: It was concluded that relatively brief but intense sprint training can result in an increase in both glycolytic and oxidative enzyme activity, maximum short-term power output, and VO2 max.
Abstract: Our purpose was to examine the effects of sprint interval training on muscle glycolytic and oxidative enzyme activity and exercise performance. Twelve healthy men (22 +/- 2 yr of age) underwent intense interval training on a cycle ergometer for 7 wk. Training consisted of 30-s maximum sprint efforts (Wingate protocol) interspersed by 2-4 min of recovery, performed three times per week. The program began with four intervals with 4 min of recovery per session in week 1 and progressed to 10 intervals with 2.5 min of recovery per session by week 7. Peak power output and total work over repeated maximal 30-s efforts and maximal oxygen consumption (VO2 max) were measured before and after the training program. Needle biopsies were taken from vastus lateralis of nine subjects before and after the program and assayed for the maximal activity of hexokinase, total glycogen phosphorylase, phosphofructokinase, lactate dehydrogenase, citrate synthase, succinate dehydrogenase, malate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase. The training program resulted in significant increases in peak power output, total work over 30 s, and VO2 max. Maximal enzyme activity of hexokinase, phosphofructokinase, citrate synthase, succinate dehydrogenase, and malate dehydrogenase was also significantly (P < 0.05) higher after training. It was concluded that relatively brief but intense sprint training can result in an increase in both glycolytic and oxidative enzyme activity, maximum short-term power output, and VO2 max.

463 citations


Journal ArticleDOI
TL;DR: It is suggested that for untrained elderly adults, an interval training programme at the intensity of Vth may be well-tolerated clinically and may significantly improve both maximal aerobic power and submaximal exercise tolerance.
Abstract: This study assessed clinical and cardiorespiratory responses after an interval training programme in sedentary elderly adults using the ventilatory threshold (Vth) as the index of exercise training intensity. A selection of 22 subjects were randomized into two groups: 11 subjects served as the training group (TG) and the others as controls (CG). Maximal exercise tests were performed on a treadmill before (T0), each month (T1, T2) and after the 3-month interval training programme period (T3). The TG subjects were individually trained at the heart rate corresponding to Vth measured at T0, T1 and T2 as the breakpoint in the oxygen uptake-carbon dioxide production relationship. Their training programme consisted of walking/jogging sessions on a running track twice a week. The sessions consisted of varying durations of exercise alternating with active recovery in such a way that the subjects slowly increased their total exercise time from an initial duration of 30 min to a final duration of 1 h. During training the heart rate was continuously monitored by a cardiofrequency meter. Compared with the daily activities of the controls, no training programme-related injuries were observed in TG. Moreover, programme adherence (73%) and attendance (97.3%) were high. The maximal oxygen uptake and Vth were increased in TG, by 20% (P<0.05) and 26% (P<0.01), respectively. Interval training at Vth also significantly increased maximal O2 pulse (P<0.05) and maximal ventilation (P<0.01). A significant decrease in submaximal ventilation (P<0.05) and heart rate (P<0.01) was also noted. These results would suggest that for untrained elderly adults, an interval training programme at the intensity of Vth may be well-tolerated clinically and may significantly improve both maximal aerobic power and submaximal exercise tolerance.

52 citations


Journal ArticleDOI
TL;DR: It is concluded that similar mechanisms may be responsible for the slow component of V˙O2 kinetics and for the fatigue following the training session.
Abstract: Elevated oxygen uptake (VO2) during moderate-intensity running following a bout of interval running training has been studied previously. To further investigate this phenomenon, the VO2 response to high-intensity exercise was examined following a bout of interval running. Well-trained endurance runners were split into an experimental group [maximum oxygen uptake, VO2max 4.73 (0.39)l x min(-1)] and a reliability group [VO2max 4.77 (0.26)l x min(-1)]. The experimental group completed a training session (4 x 800 m at 1 km x h(-1) below speed at VO2max, with 3 min rest between each 800-m interval). Five minutes prior to, and 1 h following the training session, subjects completed 6 min 30 s of constant speed, high-intensity running designed to elicit 40% delta (where delta is the difference between VO2 at ventilatory threshold and VO2max; tests 1 and 2, respectively). The slow component of VO2 kinetics was quantified as the difference between the VO2 at 6 min and the VO2 at 3 min of exercise, i.e. deltaVO2(6-3). The deltaVO2(-3) was the same in two identical conditions in the reliability group [mean (SD): 0.30 (0.10)l x min(-1) vs 0.32 (0.13)l x min(-1)]. In the experimental group, the magnitude of the slow component of VO2 kinetics was increased in test 2 compared with test 1 by 24.9% [0.27 (0.14)l x min(-1) vs 0.34 (0.08)l x min(-1), P < 0.05]. The increase in deltaVO2(6-3) in the experimental group was observed in the absence of any significant change in body mass, core temperature or blood lactate concentration, either at the start or end of tests 1 or 2. It is concluded that similar mechanisms may be responsible for the slow component of VO2 kinetics and for the fatigue following the training session. It has been suggested previously that this mechanism may be linked primarily to changes within the active limb, with the recruitment of alternative and/or additional less efficient fibres.

24 citations


Journal ArticleDOI
TL;DR: This training improves specific force and endurance of the UL, by acting centrally as reflected by oxygen pulse increase, as well as peripherally as shown by morphologic changes.
Abstract: The effects of a 6 weeks interval training with a wheelchair ergometer on the power and endurance of the upper limbs (UL) were studied in ten young able-bodied males. All subjects performed a maximal progressive test (10 W/2 min) on a wheelchair ergometer to measure the ventilation (VE), respiratory exchanges (VO2, VCO2) and oxygen pulse (O2p) at the maximal tolerated power (MTP) and ventilatory threshold (VT). Endurance capacity was measured with the tailored 45 min Square Wave Endurance Exercise Test (SWEET) from MTP and VT. Arm and forearm perimeters, diameters and skinfold thickness were also measured. The subjects were divided into a control group (CG n = 5) and a training group (TG n = 5; 3 SWEET sessions/week/6-week) with matched physical characteristics. Training the UL resulted in significant increases of parameters at MTP (power + 63%, peak VO2 + 33%, O2 pulse + 25%) and at VT (power + 125%, VO2 + 48%, O2 pulse + 33%). The UL diameter and perimeter significantly increased, and the skinfold thickness decreased. None of these variables showed a significant change in the CG. We conclude that this training improves specific force and endurance of the UL, by acting centrally as reflected by oxygen pulse increase, as well as peripherally as shown by morphologic changes.

23 citations


Journal ArticleDOI
TL;DR: After only three weeks of training, the improvement in aerobic capacity was similar to that reported after longer training periods using continuous methods, and a new interval training method which allows intense exercise stimuli on peripheral muscles with minimal cardiac strain was developed.
Abstract: Standardized guidelines for exercise training for patients with chronic congestive heart failure (CHF) have not been established. In the past, CHF patients involved in exercise training studies demonstrated a wide range of cardiac and functional impairment, with an ejection fraction between 18 and 35% and a peak VO2 between 12.2 and 25.4 ml/kg/min on average. For determination of training intensity, a VO2 between 40 and 70% of peak VO2 and/or training heart rate between 60 and 80% of peak heart rate was used. There was also a wide range for frequency (between 3 and 7 times per week) and duration of training (between 20 and 60 min per session). For aerobic exercise training only continuous training methods were applied. We have developed a new interval training method which allows intense exercise stimuli on peripheral muscles with minimal cardiac strain. After only three weeks of training, the improvement in aerobic capacity was similar to that reported after longer training periods using continuous methods. To determine work rate for work phases of interval training, a special steep ramp test was developed. By analysis of acute physical responses to this testing procedure and to the interval training, both were proven to be tolerable in CHF patients, even if their ejection fraction is as low as 13%, or peak cardiac index not greater than 1.61/m2/min, and peak VO2 less than 8.5 ml/kg/min.

14 citations


Journal ArticleDOI
TL;DR: It was demonstrated that interval training induced slight thermoregulatory changes unrelated to changes in V˙O2max and it suggested that M˙ during cold exposure could be related mainly to the level of V�'O2 max observed before training, since increases in V’O1max did not modify M�’.
Abstract: It has previously been demonstrated that metabolic heat production (M˙) during cold exposure at rest was related to maximal oxygen uptake (O2max). Consequently, an increase in O2max could allow an increase M˙ in the cold. The aim of the present study was therefore to test this hypothesis. Eight male volunteers undertook interval training (periods of 25% V˙O2max of 30-s duration and 110% V˙O2max of 60-s duration until exhaustion, five times a week over 8 weeks) to increase V˙O2max. Both before and after this physical training, they were subjected to a 10∘, 5∘ and 1∘C 2-h cold air test in a climatic chamber. During the cold exposure, rectal temperature (Tre), tympanic temperature (Tty), mean skin temperature (\(\)) and M˙ were measured as well as the time to onset of shivering (t) and body temperatures (\(\)) at t. The results showed that physical training involved an increase in O2max (14%–15%, P < 0.05). During the cold exposure, Tre was higher after training both at 10∘,5∘ and 1∘C (P < 0.05) whereas \(\) were not significantly changed. However, an increase in the sensitivity of the thermoregulatory system was attested by a decreased t at higher \(\) These slight physiological changes found after training were not related to the increases in V˙O2max. In conclusion, this study demonstrated that interval training induced slight thermoregulatory changes unrelated to changes in V˙O2max and it suggested that M˙ during cold exposure could be related mainly to the level of V˙O2max observed before training, since increases in V˙O2max did not modify M˙.

14 citations



Journal ArticleDOI
TL;DR: Congestive heart failure patients who exercise regularly can increase exercise tolerance, decrease dyspnea and fatigue, reduce the risk of arrhythmias, and improve quality of life.
Abstract: Congestive heart failure (CHF) patients who exercise regularly can increase exercise tolerance, decrease dyspnea and fatigue, reduce the risk of arrhythmias, and improve quality of life. Initial stress testing is important for assessing a patient's physiologic response to exercise and for establishing a target heart rate for an individualized exercise program. Patients may need to begin aerobic exercise with interval training and progress slowly. Strength exercise is also useful. Exercise used along with the customarily prescribed CHF medications improves symptoms more than either modality alone.

3 citations



01 Jan 1998
TL;DR: In this paper, the authors investigated the possibility of identifying changes in running kinematics and blood lactate during sprint running with different recovery times during interval type training and found that the stride rate was the most sensible variable for experimental conditions among those studied.
Abstract: INTRODUCTION: The use of interval training for improving exercise performance reduces fatigue and enhances the muscular work done. That is why it has been recommended for sprint training. When studying high intensity, short term exercises of about 10 s, there were found to be decreases in performance and increases in lactate concentrations, specially when the recovery time was short (30 to 60s). Biomechanical changes due to fatigue have been studied mostly in long-distance running. The present work was designed to verify the possibility of identifying changes in running kinematics and blood lactate during sprint running with different recovery times during interval type training. METHODS AND PROCEDURES: Six individuals executed 3 series of 5 x 50m sprints at maximum velocity, with pauses of 30, 60 and 120 s respectively. For each individual there were collected: a) video images of the first, third and fifth sprint, using the panning technic through the complete course, with reference targets each 5 m. Velocity, stride lenght and rate were calculated for each 5 m section; b) blood samples for lactate analysis after the first, third, fifth sprint and at 1, 3, 5, 7 and 10 minutes of recovery. RESULTS AND DISCUSSION: With 30s pauses, there were decreases in velocity and stride rate and increases in stride lenght through the 5 repetitions, while during the 120 s pauses these differences were attenuated. There were no significant differences between the lactate concentrations at the different pause systems. The stride rate was found to be the most sensible variable for experimental conditions among those studied. The increases observed in stride lenght were sufficient to compensate the decreases in stride rate, thus maintaining the velocity, only when fatigue was not severe. At the 5th sprint, with 30s pause, stride lenght returned to values observed at the 1st sprint, thus reducing velocity to a greater extent. CONCLUSIONS: The fact that we could not identify significant changes in blood lactate concentrations between the different series of sprints may suggest that lactate concentration measurements are not efficient indicators of fatigue in this kind of exercise, as they are for others. Therefore, stride rate could be usefull for identifying fatigue when there are no significant decreases in velocity or changes in blood lactate concentrations.

1 citations