Showing papers on "Interval training published in 2008"
TL;DR: Given the markedly lower training volume in the SIT group, these data suggest that high‐intensity interval training is a time‐efficient strategy to increase skeletal muscle oxidative capacity and induce specific metabolic adaptations during exercise that are comparable to traditional ET.
Abstract: Low-volume ‘sprint’ interval training (SIT) stimulates rapid improvements in muscle oxidative capacity that are comparable to levels reached following traditional endurance training (ET) but no study has examined metabolic adaptations during exercise after these different training strategies. We hypothesized that SIT and ET would induce similar adaptations in markers of skeletal muscle carbohydrate (CHO) and lipid metabolism and metabolic control during exercise despite large differences in training volume and time commitment. Active but untrained subjects (23 ± 1 years) performed a constant-load cycling challenge (1 h at 65% of peak oxygen uptake ( ˙ VO2peak) before and after 6 weeks of either SIT or ET (n = 5 men and 5 women per group). SIT consisted of four to six repeats of a 30 s ‘all out’ Wingate Test (mean power output ∼500 W) with 4.5 min recovery between repeats, 3 days per week. ET consisted of 40‐60 min of continuous cycling at a workload that elicited ∼65% ˙ VO2peak (mean power output ∼150 W) per day, 5 days per week. Weekly time commitment (∼1.5 versus ∼4.5 h) and total training volume (∼225 versus ∼2250 kJ week −1 ) were substantially lower in SIT versus ET. Despite these differences, both protocols induced similar increases (P < 0.05) in mitochondrial markers for skeletal muscle CHO (pyruvate dehydrogenase E1α protein content) and lipid oxidation (3-hydroxyacyl CoA dehydrogenase maximal activity) and protein content of peroxisome proliferator-activated receptor-γ coactivator-1α. Glycogen and phosphocreatine utilization during exercise were reduced after training, and calculated rates of whole-body CHO and lipid oxidation were decreased and increased, respectively, with no differences between groups (all main effects, P < 0.05). Given the markedly lower training volume in the SIT group, these data suggest that high-intensity interval training is a time-efficient strategy to increase skeletal muscle oxidative capacity and induce specific metabolic adaptations during exercise that are comparable to traditional ET.
1,151 citations
TL;DR: Exercise intensity was an important factor for improving aerobic capacity and reversing the risk factors of the metabolic syndrome.
Abstract: BACKGROUND: Individuals with the metabolic syndrome are 3 times more likely to die of heart disease than healthy counterparts. Exercise training reduces several of the symptoms of the syndrome, but ...
1,040 citations
TL;DR: High-intensity interval training is a potent time-efficient strategy to induce numerous metabolic adaptations usually associated with traditional endurance training and alter metabolic control during aerobic-based exercise.
Abstract: High-intensity interval training (HIT) is a potent time-efficient strategy to induce numerous metabolic adaptations usually associated with traditional endurance training. As little as six sessions of HIT over 2 wk or a total of only approximately 15 min of very intense exercise (approximately 600 kJ), can increase skeletal muscle oxidative capacity and endurance performance and alter metabolic control during aerobic-based exercise.
665 citations
TL;DR: It is concluded that SIT is a time-efficient strategy to elicit improvements in peripheral vascular structure and function that are comparable to ET, however, alterations in central artery distensibility may require a longer training stimuli and/or greater initial vascular stiffness than observed in this group of healthy subjects.
Abstract: Low-volume sprint interval training (SIT), or repeated sessions of brief, intense intermittent exercise, elicits metabolic adaptations that resemble traditional high-volume endurance training (ET)....
350 citations
TL;DR: An important contribution towards improved aerobic work capacity, endothelial function and cardiovascular health originates from strength training, which may serve as a substitute when whole-body aerobic exercise is contra-indicated or difficult to perform.
Abstract: Regular exercise training is recognized as a powerful tool to improve work capacity, endothelial function and the cardiovascular risk profile in obesity, but it is unknown which of high-intensity aerobic exercise, moderate-intensity aerobic exercise or strength training is the optimal mode of exercise. In the present study, a total of 40 subjects were randomized to high-intensity interval aerobic training, continuous moderate-intensity aerobic training or maximal strength training programmes for 12 weeks, three times/week. The high-intensity group performed aerobic interval walking/running at 85–95 % of maximal heart rate, whereas the moderate-intensity group exercised continuously at 60–70 % of maximal heart rate; protocols were isocaloric. The strength training group performed ‘high-intensity’ leg press, abdominal and back strength training. Maximal oxygen uptake and endothelial function improved in all groups; the greatest improvement was observed after high-intensity training, and an equal improvement was observed after moderate-intensity aerobic training and strength training. High-intensity aerobic training and strength training were associated with increased PGC-1α (peroxisome-proliferator-activated receptor γ co-activator 1α) levels and improved Ca 2+ transport in the skeletal muscle, whereas only strength training improved antioxidant status. Both strength training and moderate-intensity aerobic training decreased oxidized LDL (low-density lipoprotein) levels. Only aerobic training decreased body weight and diastolic blood pressure. In conclusion, high-intensity aerobic interval training was better than moderate-intensity aerobic training in improving aerobic work capacity and endothelial function. An important contribution towards improved aerobic work capacity, endothelial function and cardiovascular health originates from strength training, which may serve as a substitute when whole-body aerobic exercise is contra-indicated or difficult to perform.
317 citations
TL;DR: It is suggested that the RSA training protocol used in this study can be an effective training strategy for inducing aerobic and football-specific training adaptations.
Abstract: The aim of this study was to compare the effects of high-intensity aerobic interval and repeated- sprint ability (RSA) training on aerobic and an- aerobic physiological variables in male football players. Forty-two participants were randomly assigned to either the interval training group (ITG, 4 × 4 min running at 90 - 95 % of HRmax; n = 21) or repeated-sprint training group (RSG, 3 × 6 maximal shuttle sprints of 40 m; n = 21). The following outcomes were measured at base- line and after 7 weeks of training: maximum oxy- gen uptake, respiratory compensation point, football-specific endurance (Yo-Yo Intermittent Recovery Test, YYIRT), 10-m sprint time, jump height and power, and RSA. Significant group × time interaction was found for YYIRT (p = 0.003) with RSG showing greater improvement (from 1917 ± 439 to 2455 ± 488 m) than ITG (from 1846 ± 329 to 2077 ± 300 m). Similarly, a signifi- cant interaction was found in RSA mean time (p = 0.006) with only the RSG group showing an improvement after training (from 7.53 ± 0.21 to 7.37 ± 0.17 s). No other group × time interactions were found. Significant pre-post changes were found for absolute and relative maximum oxygen uptake and respiratory compensation point (p < 0.05). These findings suggest that the RSA training protocol used in this study can be an ef- fective training strategy for inducing aerobic and football-specific training adaptations. " soccer l " aerobic power
289 citations
TL;DR: It is said that the 30-15IFT leads to an MRS that simultaneously takes into account various physiological qualities elicited when performing shuttle intermittent runs, and appears to be an accurate reference speed for getting players with different physiological profiles to a similar level of cardiorespiratory demand and thus for standardizing training content.
Abstract: The objective of this study was to gather evidence supporting the accuracy of the 30-15 Intermittent Fitness Test (30-15IFT) for individualizing interval training of young intermittent sport players. In 59 young intermittent sport players (age, 16.2 +/- 2.3 years), we observed the relationships between the maximal running speed (MRS) reached at the end of the 30-15IFT (MRS30-15IFT) and physiological variables elicited by shuttle intermittent runs, including maximal oxygen uptake, explosive power of lower limbs, and the ability to repeat intense exercise bouts through cardiorespiratory recovery kinetics during exercise. To observe the capacity of the 30-15IFT to prescribe suitable running intensities for interval training sessions, we compared heart rates (HRs) reached during 3 series of intermittent runs, where distances were set according to the MRS30-15IFT and to MRS reached with 2 popular continuous field tests: the University of Montreal track test and the 20-m shuttle run test. The results show that the MRS30-15IFT is significantly correlated with all physiological variables elicited by shuttle intermittent runs (P < 0.05). Although mean HR were not different among the 3 series of intermittent runs, HR recorded during the runs based on MRS30-15IFT presented significantly less interindividual variation than when the continuously determined MRS were used as reference speeds. In conclusion, we can say that the 30-15IFT leads to an MRS that simultaneously takes into account various physiological qualities elicited when performing shuttle intermittent runs. For scheduling interval training sessions, the MRS30-15IFT appears to be an accurate reference speed for getting players with different physiological profiles to a similar level of cardiorespiratory demand and thus for standardizing training content.
288 citations
TL;DR: While selected markers of training adaptation were enhanced with twice a day training, the performance of a 1-h time trial undertaken after a 60-min steady-state ride was similar after once daily or twice every second day training programs.
Abstract: We determined the effects of a cycle training program in which selected sessions were performed with low muscle glycogen content on training capacity and subsequent endurance performance, whole body substrate oxidation during submaximal exercise, and several mitochondrial enzymes and signaling proteins with putative roles in promoting training adaptation. Seven endurance-trained cyclists/triathletes trained daily (High) alternating between 100-min steady-state aerobic rides (AT) one day, followed by a high-intensity interval training session (HIT; 8 × 5 min at maximum self-selected effort) the next day. Another seven subjects trained twice every second day (Low), first undertaking AT, then 1–2 h later, the HIT. These training schedules were maintained for 3 wk. Forty-eight hours before and after the first and last training sessions, all subjects completed a 60-min steady-state ride (60SS) followed by a 60-min performance trial. Muscle biopsies were taken before and after 60SS, and rates of substrate oxidation were determined throughout this ride. Resting muscle glycogen concentration (412 ± 51 vs. 577 ± 34 μmol/g dry wt), rates of whole body fat oxidation during 60SS (1,261 ± 247 vs. 1,698 ± 174 μmol·kg−1·60 min−1), the maximal activities of citrate synthase (45 ± 2 vs. 54 ± 1 mmol·kg dry wt−1·min−1), and β-hydroxyacyl-CoA-dehydrogenase (18 ± 2 vs. 23 ± 2 mmol·kg dry wt−1·min−1) along with the total protein content of cytochrome c oxidase subunit IV were increased only in Low (all P < 0.05). Mitochondrial DNA content and peroxisome proliferator-activated receptor-γ coactivator-1α protein levels were unchanged in both groups after training. Cycling performance improved by ∼10% in both Low and High. We conclude that compared with training daily, training twice every second day compromised high-intensity training capacity. While selected markers of training adaptation were enhanced with twice a day training, the performance of a 1-h time trial undertaken after a 60-min steady-state ride was similar after once daily or twice every second day training programs.
286 citations
TL;DR: This study demonstrated that 18 h of repeated high-intensity exercise sessions over 6 weeks (3 d.week-1) is a powerful method to increase whole-body and skeletal muscle capacities to oxidize fat and carbohydrate in previously untrained individuals.
Abstract: High-intensity aerobic interval training (HIIT) is a compromise between time-consuming moderate-intensity training and sprint-interval training requiring all-out efforts. However, there are few dat...
284 citations
TL;DR: It is demonstrated that exercise training reduces the impact of the metabolic syndrome and that the magnitude of the effect depends on exercise intensity.
Abstract: Aims The recent development of a rat model that closely resembles the metabolic syndrome allows to study the mechanisms of amelioration of the syndrome by exercise training. Here, we compared the effectiveness for reducing cardiovascular risk factors by exercise training programmes of different exercise intensities. Methods and results Metabolic syndrome rats were subjected to either continuous moderate-intensity exercise (CME) or high-intensity aerobic interval training (AIT). AITwas more effective than CME at reducing cardiovascular disease risk factors linked to the metabolic syndrome. Thus, AIT produced a larger stimulus than CME for increasing maximal oxygen uptake (VO2max; 45 vs. 10%, P , 0.01), reducing hypertension (20 vs. 6 mmHg, P , 0.01), HDL cholesterol (25 vs. 0%, P , 0.05), and beneficially altering metabolism in fat, liver, and skeletal muscle tissues. Moreover, AIT had a greater beneficial effect than CME on sensitivity of aorta ring segments to acetylcholine (2.7- vs. 2.0-fold, P , 0.01), partly because of intensity-dependent effects on expression levels of nitric oxide synthase and the density of caveolae, and a greater effect than CME on the skeletal muscle Ca 2þ handling (50 vs. 0%, P , 0.05). The two exercise training programmes, however, were equally effective at reducing body weight and fat content. Conclusion High-intensity exercise training was more beneficial than moderate-intensity exercise training for reducing cardiovascular risk in rats with the metabolic syndrome. This was linked to more superior effects on VO2max, endothelial function, blood pressure, and metabolic parameters in several tissues. These results demonstrate that exercise training reduces the impact of the metabolic syndrome and that the magnitude of the effect depends on exercise intensity.
213 citations
TL;DR: Circuit training alone induced strength and power improvements that were significantly greater than when resistance and endurance training were combined, irrespective of the intrasession sequencing.
Abstract: The purpose of this study was to examine the influence of the sequence order of high-intensity endurance training and circuit training on changes in muscular strength and anaerobic power. Forty-eight physical education students (ages, 21.4 +/- 1.3 years) were assigned to 1 of 5 groups: no training controls (C, n = 9), endurance training (E, n = 10), circuit training (S, n = 9), endurance before circuit training in the same session, (E+S, n = 10), and circuit before endurance training in the same session (S+E, n = 10). Subjects performed 2 sessions per week for 12 weeks. Resistance-type circuit training targeted strength endurance (weeks 1-6) and explosive strength and power (weeks 7-12). Endurance training sessions included 5 repetitions run at the velocity associated with Vo2max (Vo2max) for a duration equal to 50% of the time to exhaustion at Vo2max; recovery was for an equal period at 60% Vo2max. Maximal strength in the half squat, strength endurance in the 1-leg half squat and hip extension, and explosive strength and power in a 5-jump test and countermovement jump were measured pre- and post-testing. No significant differences were shown following training between the S+E and E+S groups for all exercise tests. However, both S+E and E+S groups improved less than the S group in 1 repetition maximum (p < 0.01), right and left 1-leg half squat (p < 0.02), 5-jump test (p < 0.01), peak jumping force (p < 0.05), peak jumping power (p < 0.02), and peak jumping height (p < 0.05). The intrasession sequence did not influence the adaptive response of muscular strength and explosive strength and power. Circuit training alone induced strength and power improvements that were significantly greater than when resistance and endurance training were combined, irrespective of the intrasession sequencing.
TL;DR: For short-term training of relatively untrained men, the Army's new Standardized Physical Training program and a weight-based training experimental program can produce similar, significant, and meaningful improvements in military physical performance.
Abstract: Various physical demands are placed on soldiers, whose effectiveness and survivability depend on their combat-specific physica fitness. Because sport training programs involving weight-basec training have proven effective, this study examined the value of such a program for short-term military training using combat-relevant tests. A male weight-based training (WBT) group (n = 15. mean ± SD: 27.0 ± 4.7 years, 173.8 ± 5.8 cm, 80.9 ± 12.7 kg) performed full-body weight-based training workouts, 3.2-km runs, interval training, agility training, and progressively loaded 8-km backpack hikes. A male Army Standardized Physical Training (SPT) group (n = 17; mean ± SD: 29.0 ± 4.6 years, 1 79.7 ± 8.2 cm, 84.5 ± 10.4 kg) followed the new Army Standardized Physical Training program of stretching, varied calisthenics, movement drills, sprint intervals, shuttle running, and distance runs. Both groups exercised for 1.5 hours a day, 5 days a week for 8 weeks. The following training-induced changes were statistically significant (P < 0.05) for both training groups: 3.2-km run or walk with 32-kg load (minutes), 24.5 ± 3.2 to 21.0 ± 2.8 (SPT) and 24.9 ± 2.8 to 21.1 ± 2.2 (WBT); 400-m run with 18-kg load (seconds), 94.5 ± 14.2 to 84.4 ± 11.9 (SPT) and 100.1 ± 16.1 to 84.0 ± 8.4 (WBT); obstacle course with 18-kg load (seconds), 73.3 ± 10.1 to 61.6 ± 7.7 (SPT) and 66.8 ± 10.0 to 60.1 ± 8.7 (WBT); 5 30-m sprints to prone (seconds), 63.5 ± 4.8 to 59.8 ± 4.1 (SPT) and 60.4 ± 4.2 to 58.9
2.7 (WBT); and 80-kg casualty rescue from 50 m (seconds), 65.8 ± 40.0 to 42.1 ± 9.9 (SPT) and 57.6 ± 22.0 to 44.2 8.8 (WBT). Of these tests, only the obstacle course showed significant difference in improvement between the two training groups. Thus, for short-term (i.e., 8-week) training of relatively untrained men, the Army's new Standardized Physical Training program and a weight-based training experimental program can produce similar, significant, and meaningful improvements in military physical performance. Further research would be needed to determine whether weight-based training provides an advantage over a longer training period.
TL;DR: The exercise model significantly improved functional capacity and quality of life compared with the control group in patients with CHF and Improvements in quality ofLife were significantly related to functional capacity.
Abstract: The aim of this study was to evaluate the effectiveness of a novel group-based aerobic interval training of high intensity on functional capacity and quality of life in patients with chronic heart failure (CHF) and examine the relation between changes in functional capacity and quality of life. Eighty patients with stable CHF (63 men, 17 women; mean age 70.1 ± 7.9 [SD] years; left ventricular ejection fraction 30 ± 8.5%) on optimal medical treatment were randomly assigned to either a 16-week group-based aerobic high-intensity interval training model twice weekly for 65 to 80 minutes/day (n = 40) or a control group (n = 40) that received standard care. Functional capacity was measured using the 6-minute walk test and cycle ergometer test. Quality of life was measured using the Minnesota Living with Heart Failure Questionnaire. After 16 weeks, functional capacity improved significantly in the exercise group compared with the control group measured using the 6-minute walk test (+58 vs −15 meters; p
TL;DR: The results support the implementation of a group-based aerobic interval training program to improve long-term effects on functional capacity and the quality of life in patients with chronic heart failure.
Abstract: Studies on the long-term effects of exercise training programs on functional capacity and the quality of life in patients with chronic heart failure (CHF) are sparse. The aim of this study was to evaluate the long-term effects of group-based, high-intensity interval training on functional capacity and the quality of life in 80 patients with stable CHF (mean age 70.1 ± 7.9 years) in New York Heart Association classes II to IIIB. Patients were randomized to either an exercise group (n = 40) or a control group (n = 40). The mean ejection fractions at baseline were 31 ± 8% in the exercise group and 31 ± 1% in the control group. The exercise group exercised twice a week for 4 months in addition to 4 consultations with a CHF nurse. Six-minute walking distance, workload and exercise time on a cycle ergometer test, and the quality of life were measured at baseline and 4 and 12 months after enrollment. After 4 months, functional capacity (6-minute walking distance +58 vs −15 m, p
TL;DR: The results suggest that increases in betam(in vitro) and MCT relative abundance are not linked to the degree of muscle lactate and H+ accumulation during training and that training that results in a decrease in H- accumulation and an increase in PCr resynthesis can actually reduce the decrease in muscle H+ during the recovery from supramaximal exercise.
Abstract: The purpose of this study was to investigate the effects of high-intensity interval training (3 days/wk for 5 wk), provoking large changes in muscle lactate and pH, on changes in intracellular buff...
TL;DR: Lactate and rate of perceived exertion was monitored in 6 male subjects training for and competing in a mixed martial arts event held in Butte, Montana to determine the metabolic demands of the sport and the effectiveness of the prebout interval training programs chosen to help prepare the competitors for this event.
Abstract: Lactate and rate of perceived exertion (RPE) was monitored in 6 male subjects training for and competing in a mixed martial arts event held in Butte, Montana, to determine 1) the metabolic demands of the sport and 2) the effectiveness of the prebout interval training programs chosen to help prepare the competitors for this event. The training lactate measurements ranged from 8.1 to 19.7 mmol.L, and the training RPE levels ranged from 15 to 19 on Borg's Category Scale of perceived exertion, the scores of which ranged from 6 to 20. The postbout lactate measurements ranged from 10.2 to 20.7 mmol.L, and the post-bout RPE measurements ranged from 13 to 19. Of the 4 subjects that had both training and postbout lactate measurements, 3 had obtained lactate levels during training that exceeded lactate levels immediately after the bout. This indicated that, when using lactate measurements as a benchmark, the conditioning training was effective for these 3 athletes. When we used RPE scores as a benchmark, the conditioning was effective for all 4 subjects because all subjects reached 18-19 during their training, which was at least as high as their reported post-bout RPE levels.
TL;DR: The obese women with or without diabetes perceived the intermittent exercise as being less hard than the continuous exercise, and a training program based on intermittent exercises produced beneficial effects on obesity and type 2 diabetes.
Abstract: Introduction:Exercise has beneficial effects on obesity and diabetes treatments. However, obese subjects do not closely adhere to training programs probably because of the monotony of the continuous exercise that is frequently proposed. To increase adherence to training programs, intermitten
TL;DR: It is shown that aerobic interval training increases the maximal rate of Ca2+ uptake by 30%.
Abstract: Objective Reduced activity of the sarcoplasmic reticulum Ca2+ ATPase-2a (SERCA-2a) contributes to myocardial dysfunction. Exercise training improves myocardial Ca2+-handling, but SERCA-2a function ...
TL;DR: In this paper, the authors proposed that interval training will provide a more powerful stimulus for improving insulin sensitivity than traditional low-to-moderate intensity aerobic conditioning, and further proposed that these affects will be due to greater changes in specific metabolic pathways associated with glycolysis, aerobic metabolism, beta-oxidation, and mitochondrial biogenesis.
TL;DR: It is demonstrated that junior soccer players may benefit from aerobic training to attenuate the decline in short-passing ability caused by a short bout of intermittent activities completed at the same pretraining workload.
Abstract: To examine the effects of aerobic interval training on the decline in short-passing ability caused by a short bout of high-intensity intermittent activities. For this randomized controlled trial, 2...
TL;DR: A clinical trial suggests that ITE can benefit CMT patients especially in their functional performance and subjective perception of pain and fatigue, and the improvement observed at the end of the first supervised period ITE was maintained after the second unsupervised home period, although there was no further improvement in performance and tolerance.
Abstract: Exercise intolerance and undue fatigue are common complaints in patients with Charcot-Marie-Tooth (CMT) disease. Reduced physical ability is due directly to the disease, but it is also due to physical deconditioning. The aim of this study was to test whether 24 weeks of interval-training exercise (ITE) cycling can significantly improve physiological, neuromuscular, and functional capacities and alleviate fatigue in CMT patients. Eight CMT patients (4 CMT1A and 4 CMT2) participated in ITE for 3 nonconsecutive days per week. Cardiovascular fitness, muscle strength, fatigue resistance, and functional capacities were measured before and after 12 weeks of supervised hospital training and again after another 12 weeks of unsupervised home training. Training was well tolerated. There were significant improvements in cardiorespiratory capacities, isokinetic concentric strength, and functional ability measurements. All patients experienced an improvement in their self-reported visual analogic scale for fatigue and pain during training. However, there was no significant change in their isometric force production and indices of fatigue resistance after training. Although the improvement in exercise tolerance may be due in part to reversal of the deconditioning effect of their related sedentary lifestyle, this clinical trial suggests that ITE can benefit CMT patients especially in their functional performance and subjective perception of pain and fatigue. Moreover, the improvement observed at the end of the first supervised period ITE was maintained after the second unsupervised home period, although there was no further improvement in performance and tolerance.
TL;DR: Some indication is shown that situational high-intensity task training was more efficient than straight-line sprinting in improving anaerobic endurance measured by the 300-yard shuttle run test.
Abstract: The purpose of this study was to evaluate changes in anaerobic endurance in elite First-league soccer players throughout 2 consecutive seasons, in 2 phases, with and without high-intensity situational drills Eighteen soccer players were tested before and after the 8-week summer conditioning and again in the next season The measured variables included 300-yard shuttle run test, maximal heart rate, and maximal blood lactate at the end of the test During the first phase of the study, the traditional sprint training was performed only 2 x weeks and consisted of 15 bouts of straight-line sprinting In the second year the 4 x 4 min drills at an intensity of 90-95% of HRmax, separated by periods of 3-minute technical drills at 55-65% of HRmax were introduced Statistical significance was set at P
TL;DR: The 4 patients with chronic heart failure in this case series who participated in this program experienced improvements in physical capacity and quality of life and had no adverse events, consistent with recent evidence supporting the efficacy of high-intensity interval training in people with CHF.
Abstract: Background and Purpose: The purpose of this case report is to describe the responses of 4 patients with chronic heart failure (CHF) to a novel rehabilitation program: a group-based, high-intensity, interval-training program that includes aerobic, resistance, flexibility, and balance activities
Case Descriptions: Four patients (55–71 years of age) with CHF (New York Heart Association class III) participated in the rehabilitation program twice per week for 16 weeks Outcome measures included a 6-minute walk test (6MWT), a cycle ergometer test (aerobic capacity), and a quality-of-life questionnaire
Outcomes: Patients 1, 2, and 3 increased their aerobic capacity (17%, 25%, and 52%, respectively) Patient 4 did not complete the cycle ergometer test because of limitations associated with his pacemaker All patients increased their 6MWT distance (117, 66, 135, and 143 m for patients 1, 2, 3, and 4, respectively) No adverse events were reported
Discussion: The Norwegian Ullevaal Model of cardiac rehabilitation is a novel high-intensity, interval-training program The 4 patients with CHF in this case series who participated in this program experienced improvements in physical capacity and quality of life and had no adverse events These results are consistent with recent evidence supporting the efficacy of high-intensity interval training in people with CHF Randomized clinical trials are needed to evaluate the clinical efficacy of this group-based, high-intensity, aerobic interval-training program for patients with CHF
TL;DR: It is concluded that an exercise program that includes both high and low-intensity activities is more efficient to ensure the reduction of a greater number of cardiac risk variables.
Abstract: BACKGROUND: Aerobic exercise is an important ally in the fight against cardiovascular risk factors. However, the effects of high-intensity exercise on these factors are still poorly known. OBJECTIVE: To compare the effects of aerobic and anaerobic exercise protocols on cardiac risk factors. METHODS: 22 individuals with mean age of 40±8 years were distributed into the following groups: control (CO), endurance training (ET) and interval training (IT). The protocols lasted 12 weeks, three times a week, with intensities of 10% below and 20% above the anaerobic threshold (AnT). The following measurements were taken: total body mass (TBM), body mass index (BMI), waist circumference (WC), hip circumference (HC), and body composition, in addition to plasma concentrations of glucose (GLU), total cholesterol (CHO), and triglycerides (TG). Waist-hip ratio (WHR) and conicity index (C index) were also calculated. RESULTS: The TBM, BMI, WC, GLU, and body composition variables showed significant changes in the ET and IT groups. CHO and HC values were significantly reduced in the ET group, whereas WHR showed a significant reduction in the IT group. AnT and C index in the IT group were significantly different in relation to ET. CONCLUSION: In view of the differences found in the results of the variables studied in relation to the training performed, we conclude that an exercise program that includes both high and low-intensity activities is more efficient to ensure the reduction of a greater number of cardiac risk variables.
TL;DR: It is shown that an ITP with the modified ES-LCE can elicit marked improvements in ES- lCE performance, peak power output, peak metabolic and cardiorespiratory responses, and muscle strength in men with SCI, even in those subjects whose performance has plateaued during training on the standard ES- LCE.
Abstract: Computer-controlled electrical stimulation (ES)-induced leg cycle ergometer (ES-LCE) exercise can be beneficial for individuals with spinal cord injury (SCI), but exercise performance is often insufficient for eliciting continuous gains in cardiopulmonary training adaptations. The first purpose of this study was to determine whether a modified ES-LCE improved exercise performance and responses compared with the standard ES-LCE. Modifications to the ES-LCE included increased ES current amplitude (140-300 mA), added shank muscle activation, and increased ES firing angle ranges (+55 degrees). The second purpose was to evaluate the effects of a 6-week interval training program (ITP) with this modified methodology on ES-LCE exercise performance, peak metabolic and cardiorespiratory responses, and muscle strength in experienced and novice riders. No significantly different peak values for power output and stroke volume were found for the two systems, but the modified ES-LCE elicited significantly higher peak values for oxygen uptake (+22%), carbon dioxide production (+51%), pulmonary ventilation (+37%), cardiac output (+32%), heart rate (+19%), and blood lactate concentration (+50%). Power output, metabolic rate, and lower-limb muscle strength increased significantly following training. This study showed that an ITP with the modified ES-LCE can elicit marked improvements in ES-LCE performance (peak power output), peak metabolic and cardiorespiratory responses, and muscle strength in men with SCI, even in those subjects whose performance has plateaued during training on the standard ES-LCE.
TL;DR: It is demonstrated that moderate- to high-intense cardiovascular endurance and neuromuscular power training do not appear to be compatible when performed simultaneously and conventional baseball conditioning involving significant amounts of cardiovascular endurance training should be altered to include more speed/power interval training.
Abstract: Exercise professionals seeking to develop evidence-based training programs rely on several training principles demonstrated through research and professional experience. In an effort to further research examining these principles, an investigation was designed and completed to evaluate the compatibility of cardiovascular endurance and neuromuscular power training. Sixteen Division-I collegiate baseball players were divided into two training groups with lower body power measured before and after their college playing season. The two groups differed in training in that one group performed moderate- to high-intense cardiovascular endurance training 3-4 days per week throughout the season, while the other group participated in speed/speed endurance training. A significant difference between groups (P < .05) was identified in the change in lower body power during the baseball season. During the season, the endurance training group decreased an average of 39.50 +/- 128.03 watts while the speed group improved an average of 210.63 +/- 168.96 watts. These data demonstrate that moderate- to high-intense cardiovascular endurance and neuromuscular power training do not appear to be compatible when performed simultaneously. For baseball players, athletes who rely heavily on power and speed, conventional baseball conditioning involving significant amounts of cardiovascular endurance training should be altered to include more speed/power interval training.
Journal Article•
TL;DR: It is concluded that both continuous and intermittent training exercises were equally effective in improving t-peak and [La]peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ1) and removal (γ2) indexes.
Abstract: The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS) using field tests. Twenty-four male sport students were equally divided into continuous (CT) and intermittent (IT) physically trained groups. Another six participants acted as non-trained controls (CG). The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an incremental exercise test to assess their MAS, and a 30- second supra-maximal exercise followed by 30 minutes of active recovery to determine the individual blood lactate recovery curve. It was found that exercise training has significantly increased MAS (p < 0.001), the lactate exchange and removal abilities as well as the lactate concentrations at the beginning of the recovery ([La]-(0)); for both CT and IT groups; this was accompanied by a significant reduction of the time to lactate-peak. Nevertheless, the improvement in MAS was significantly higher (p < 0.001) post-intermittent (15.1 % ± 2.4) than post-continuous (10.3 % ± 3.2) training. The lactate-exchange and removal abilities were also significantly higher for IT than for CT-group (P<0.05). Moreover, IT-group showed a significantly shorter half-time of the blood lactate (t-½-[La]) than CT-group (7.2 ± 0.5 min vs 7.7 ± 0.3 min, respectively) (p < 0.05). However, no significant differences were observed in peak blood lactate concentration ([La]peak), time to reach [La]peak (t-[La]peak), and [La]-(0) between the two physically-trained groups. We conclude that both continuous and intermittent training exercises were equally effective in improving t-[La]peak and [La]peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ1) and removal (γ2) indexes. Key pointsCoaches and athletes need to be aware of the potentiality positive effects of exercise intensity.Improvements in physical fitness are associated with a concomitant increase in the lactate removal ability.In order to reduce lactate accumulation and increase maximal aerobic speed maximally, interval training method, with work speeds equal to 90% - 100% of MAS, may be the effective way when compared with continuous training method.
TL;DR: In conclusion, periodized, running-specific strength training minimizes the loss of stride length that typically occurs in endurance runners during fatiguing running bouts.
Abstract: The purpose of this study was to determine the effects of a running-specific, periodized strength training program (performed over the specific period [8 weeks] of a 16-week macrocycle) on endurance-trained runners' capacity to maintain stride length during running bouts at competitive speeds. Eighteen well-trained middle-distance runners completed the study (personal bests for 1500 and 5000 m of 3 minutes 57 seconds +/- 12 seconds and 15 minutes 24 seconds +/- 36 seconds). They were randomly assigned to each of the following groups (6 per group): periodized strength group, performing a periodized strength training program over the 8-week specific (intervention) period (2 sessions per week); nonperiodized strength group, performing the same strength training exercises as the periodized group over the specific period but with no week-to-week variations; and a control group, performing no strength training at all during the specific period. The percentage of loss in the stride length (cm)/speed (m.s) (SLS) ratio was measured by comparing the mean SLS during the first and third (last) group of the total repetitions, respectively, included in each of the interval training sessions performed at race speeds during the competition period that followed the specific period. Significant differences (p < 0.05) were found in mean percentage of SLS loss between the 3 study groups, with the periodized strength group showing no significant SLS change (0.36 +/- 0.95%) and the 2 other groups showing a moderate or high SLS loss (-1.22 +/- 1.5% and -3.05 +/- 1.2% for the nonperiodized strength and control groups, respectively). In conclusion, periodized, running-specific strength training minimizes the loss of stride length that typically occurs in endurance runners during fatiguing running bouts.
Journal Article•
TL;DR: Heart rates during training and competition were significantly higher than maximum heart rates obtained during laboratory exercise testing, and training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment ofmaximum heart rate, but instead on maximum heart rate measure obtained either during training or during competition.
Abstract: A percentage of either measured or predicted maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate in athletes may be greater during competition or training than during laboratory exercise testing. Thus, the aim of the present investigation was to determine if endurance-trained runners train and compete at or above laboratory measures of 'maximum' heart rate. Maximum heart rates were measured utilising a treadmill graded exercise test (GXT) in a laboratory setting using 10 female and 10 male National Collegiate Athletic Association (NCAA) division 2 cross-country and distance event track athletes. Maximum training and competition heart rates were measured during a high-intensity interval training day (TR HR) and during competition (COMP HR) at an NCAA meet. TR HR (207 ± 5.0 b·min(-1); means ± SEM) and COMP HR (206 ± 4 b·min(-1)) were significantly (p < 0.05) higher than maximum heart rates obtained during the GXT (194 ± 2 b·min(-1)). The heart rate at the ventilatory threshold measured in the laboratory occurred at 83.3 ± 2.5% of the heart rate at VO2 max with no differences between the men and women. However, the heart rate at the ventilatory threshold measured in the laboratory was only 77% of the maximal COMP HR or TR HR. In order to optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate obtained either during training or during competition. Key pointsA percentage of maximum heart rate is commonly used to prescribe and measure exercise intensity. However, maximum heart rate may be greater during competition or training than during laboratory exercise testing.Heart rates during training and competition were significantly higher than maximum heart rates obtained during laboratory exercise testing.To optimize training-induced adaptation, training intensity for NCAA division 2 distance event runners should not be based on laboratory assessment of maximum heart rate, but instead on maximum heart rate measure obtained either during training or during competition.
TL;DR: The present study shows that breathing 100% oxygen enriched air during aerobic interval training in stable coronary artery disease patients does not improve peak oxygen uptake above the level attained with normoxic training.
Abstract: Objectives. To investigate whether hyperoxic aerobic interval training improves training quality in coronary artery disease patients. Design. Twenty-one stable coronary artery disease patients were recruited to hyperoxic (n=10) and normoxic (n=11) groups (age: 62.4±6.8 years). Patients underwent 30 supervised 4×4 minutes interval training sessions using treadmill walking, at 85–95% of peak heart rate. Results. Arterial saturation was significantly increased by 3% at pretest from normoxic to hyperoxic testing conditions. Peak oxygen uptake and stroke volume increased significantly by 16% and 17% (p<0.05) and by 16% and 18% (p<0.05) in the hyperoxic and normoxic training groups respectively. No difference was revealed between groups for peak oxygen uptake and stroke volume. Blood volumes were unchanged from pre to post training. Peak oxygen uptake measured in normoxia and hyperoxia in the hyperoxia training group revealed no difference. Conclusion. The present study shows that breathing 100% oxygen enriched...