Showing papers on "Interval training published in 2009"
426 citations
TL;DR: The efficacy of a high intensity exercise protocol, involving only ~250 kcal of work each week, to substantially improve insulin action in young sedentary subjects is remarkable and can be used as a strategy to reduce metabolic risk factors in young and middle aged sedentary populations who otherwise would not adhere to time consuming traditional aerobic exercise regimes.
Abstract: Traditional high volume aerobic exercise training reduces cardiovascular and metabolic disease risk but involves a substantial time commitment. Extremely low volume high-intensity interval training (HIT) has recently been demonstrated to produce improvements to aerobic function, but it is unknown whether HIT has the capacity to improve insulin action and hence glycemic control. Sixteen young men (age: 21 ± 2 y; BMI: 23.7 ± 3.1 kg·m-2; VO2peak: 48 ± 9 ml·kg-1·min-1) performed 2 weeks of supervised HIT comprising of a total of 15 min of exercise (6 sessions; 4–6 × 30-s cycle sprints per session). Aerobic performance (250-kJ self-paced cycling time trial), and glucose, insulin and NEFA responses to a 75-g oral glucose load (oral glucose tolerance test; OGTT) were determined before and after training. Following 2 weeks of HIT, the area under the plasma glucose, insulin and NEFA concentration-time curves were all reduced (12%, 37%, 26% respectively, all P < 0.001). Fasting plasma insulin and glucose concentrations remained unchanged, but there was a tendency for reduced fasting plasma NEFA concentrations post-training (pre: 350 ± 36 v post: 290 ± 39 μmol·l-1, P = 0.058). Insulin sensitivity, as measured by the Cederholm index, was improved by 23% (P < 0.01), while aerobic cycling performance improved by ~6% (P < 0.01). The efficacy of a high intensity exercise protocol, involving only ~250 kcal of work each week, to substantially improve insulin action in young sedentary subjects is remarkable. This novel time-efficient training paradigm can be used as a strategy to reduce metabolic risk factors in young and middle aged sedentary populations who otherwise would not adhere to time consuming traditional aerobic exercise regimes.
407 citations
TL;DR: It was found that 3 months of twice weekly high-intensity exercise sessions reduced several known cardiovascular risk factors in obese adolescents more than that observed after a multitreatment strategy, which was initiated as hospital treatment.
Abstract: The aim of the present study was to compare the effects of a multidisciplinary approach (MTG) and aerobic interval training (AIT) on cardiovascular risk factors in overweight adolescents. A total of 62 overweight and obese adolescents from Trondelag County in Norway, referred to medical treatment at St Olav's Hospital, Trondheim, Norway, were invited to participate. Of these, 54 adolescents (age, 14.0 +/- 0.3 years) were randomized to either AIT (4 x 4 min intervals at 90% of maximal heart rate, each interval separated by 3 min at 70%, twice a week for 3 months) or to MTG (exercise, dietary and psychological advice, twice a month for 12 months). Follow-up testing occurred at 3 and 12 months. VO(2max) (maximal oxygen uptake) increased more after AIT compared with MTG, both at 3 months (11 compared with 0%; P<0.01) and 12 months (12 compared with -1%; P<0.01). AIT enhanced endothelial function compared with MTG at both 3 months (absolute change, 5.1 compared with 3.9%; P<0.01) and 12 months (absolute change, 6.3 compared with 1.0%; P<0.01). AIT was favourable compared with MTG in reducing BMI (body mass index), percentage of fat, MAP (mean arterial blood pressure) and increasing peak oxygen pulse. In addition, AIT induced a more favourable regulation of blood glucose and insulin compared with MTG. In conclusion, the novel findings of the present proof-of-concept study was that 3 months of twice weekly high-intensity exercise sessions reduced several known cardiovascular risk factors in obese adolescents more than that observed after a multitreatment strategy, which was initiated as hospital treatment. Follow-up at 12 months confirmed that AIT improved or maintained these risk factors to a better degree than MTG.
342 citations
TL;DR: In this article, the authors compared the effects of AIT versus MCT on peak oxygen uptake (Vo(2peak) in cardiac patients and found that AIT was more effective than MCT.
301 citations
TL;DR: Cellular and molecular mechanisms of myocardial adaptation to exercise training are discussed and hypothesized that high-intensity aerobic interval training results in a greater beneficial adaptation of the heart compared with that observed after low-to-moderate exercise intensity.
Abstract: We hypothesized that high-intensity aerobic interval training results in a greater beneficial adaptation of the heart compared with that observed after low-to-moderate exercise intensity. This is supported by recent epidemiological, experimental, and clinical studies. Cellular and molecular mechanisms of myocardial adaptation to exercise training are discussed in this review
286 citations
01 Jan 2009
TL;DR: In this paper, the impact of interval and continuous training with untrained to moderately trained subjects does not support the current interval craze, but the evidence does suggest that short intense training bouts and longer continuous exercise sessions should both be a part of effective endurance training.
Abstract: Endurance training involves manipulation of intensity, duration, and frequency of training sessions. The relative impact of short, high-intensity training versus longer, slower distance training has been studied and debated for decades among athletes, coaches, and scientists. Currently, the popularity pendulum has swung towards high-intensity interval training. Many fitness experts, as well as some scientists, now argue that brief, high-intensity interval work is the only form of training necessary for performance optimization. Research on the impact of interval and continuous training with untrained to moderately trained subjects does not support the current interval craze, but the evidence does suggest that short intense training bouts and longer continuous exercise sessions should both be a part of effective endurance training. Elite endurance athletes perform 80 % or more of their training at intensities clearly below their lactate threshold and use high-intensity training surprisingly sparingly. Studies involving intensification of training in already well-trained athletes have shown equivocal results at best. The available evidence suggests that combining large volumes of low-intensity training with careful use of high-intensity interval training throughout the annual training cycle is the best-practice
190 citations
TL;DR: Both HIT and HBT were found to be effective training modes for adolescent handball players, however, HBT should be considered as the preferred training method due to its higher game-based specificity.
Abstract: This study compared the effect of high-intensity interval training (HIT) versus specific game-based handball training (HBT) on handball performance parameters. Thirty-two highly-trained adolescents (15.5+/-0.9 y) were assigned to either HIT (n=17) or HBT (n=15) groups, that performed either HIT or HBT twice per week for 10 weeks. The HIT consisted of 12-24 x 15 s runs at 95% of the speed reached at the end of the 30-15 Intermittent Fitness Test (V(IFT)) interspersed with 15 s passive recovery, while the HBT consisted of small-sided handball games performed over a similar time period. Before and after training, performance was assessed with a counter movement jump (CMJ), 10 m sprint time (10 m), best (RSAbest) and mean (RSAmean) times on a repeated sprint ability (RSA) test, the V(IFT) and the intermittent endurance index (iEI). After training, RSAbest (-3.5+/-2.7%), RSAmean (-3.9+/-2.2%) and V(IFT) (+6.3+/-5.2%) were improved (P<0.05), but there was no difference between groups. In conclusion, both HIT and HBT were found to be effective training modes for adolescent handball players. However, HBT should be considered as the preferred training method due to its higher game-based specificity.
189 citations
TL;DR: A clinically relevant protective effect of acute exercise on the vasculature that is clearly exercise intensity dependent and tightly related to exercise-induced antioxidant capacity is revealed.
166 citations
TL;DR: In this article, a 6-month supervised high-intensity interval exercise training program was shown to reduce the late luminal loss of stents in stable or unstable angina in patients with coronary artery disease.
149 citations
Journal Article•
TL;DR: Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers and further improves middle distance swimming performance, while two weekly sessions of dry land strength training improves the swimming force.
Abstract: A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11) or a control group (n = 9) from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre- and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high- intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers. Key pointsTwo weekly sessions of dry land strength training improves the swimming force.Two weekly sessions of high-intensity endurance training did not cause improved endurance capacity.It may seem that dry land strength training can improve middle distance performance.
121 citations
TL;DR: The use of HIIT to induce significant aerobic improvements is effective and efficient and chronic BA supplementation may further enhance HIIT, improving endurance performance and lean body mass.
Abstract: Background: Intermittent bouts of high-intensity exercise result in diminished stores of energy substrates, followed by an accumulation of metabolites, promoting chronic physiological adaptations. In addition, β-alanine has been accepted has an effective physiological hydrogen ion (H + ) buffer. Concurrent high-intensity interval training (HIIT) and β-alanine supplementation may result in greater adaptations than HIIT alone. The purpose of the current study was to evaluate the effects of combining β-alanine supplementation with high-intensity interval training (HIIT) on endurance performance and aerobic metabolism in recreationally active college-aged men. Methods: Forty-six men (Age: 22.2 ± 2.7 yrs; Ht: 178.1 ± 7.4 cm; Wt: 78.7 ± 11.9; VO2peak: 3.3 ± 0.59 l·min-1) were assessed for peak O 2 utilization (VO 2 peak), time to fatigue (VO 2TTE ), ventilatory threshold (VT), and total work done at 110% of pre-training VO2peak (TWD). In a double-blind fashion, all subjects were randomly assigned into one either a placebo (PL – 16.5 g dextrose powder per packet; n = 18) or β-alanine (BA – 1.5 g β-alanine plus 15 g dextrose powder per packet; n = 18) group. All subjects supplemented four times per day (total of 6 g/day) for the first 21-days, followed by two times per day (3 g/day) for the subsequent 21 days, and engaged in a total of six weeks of HIIT training consisting of 5–6 bouts of a 2:1 minute cycling work to rest ratio. Results: Significant improvements in VO 2 peak, VO 2TTE , and TWD after three weeks of training were displayed (p < 0.05). Increases in VO 2 peak, VO 2TTE , TWD and lean body mass were only significant for the BA group after the second three weeks of training.
TL;DR: Pro‐Q Diamond staining revealed changes in expression were associated with phosphorylated protein species, which provides novel information regarding muscle adaptation to interval training.
Abstract: No previous study has used proteomics to investigate the effects of exercise training on human skeletal muscle. Five recreationally active men completed a 6-wk training programme involving three sessions per week, utilising six 1-min bouts at maximum oxygen uptake (V O2max) interspersed with 4 min at 50% V O2max. Vastus lateralis was biopsied at standardised times before and after the training intervention. Protein expression profiling was performed using differential analysis of 2-DE gels; complemented with quantitative analysis (iTRAQ) of tryptic peptides from 1-DE gel lane-segments using LC-MALDI MS/MS. Interval training increased average V O2max (7%; p<0.001) and was associated with greater expression of mitochondrial components, including succinate dehydrogenase, trifunctional protein-α and ATP synthase α- and β-chains. 2-DE resolved 256 spots, and paired t-tests identified 20 significant differences in expression (false discovery rate <10%). Each differentially expressed gene product was present as multiple isoelectric species. Therefore, the differences in spot expression represent changes in post-transcriptional or post-translational processing. In particular, modulation of muscle creatine kinase and troponin T were prominent. Pro-Q Diamond staining revealed these changes in expression were associated with phosphorylated protein species, which provides novel information regarding muscle adaptation to interval training.
TL;DR: Patients with tetraplegia were able to improve their physical capacity through regular hand cycle interval training, without participant-reported shoulder-arm pain or discomfort.
Abstract: Background: Regular physical activity is important for people with tetraplegia to maintain fitness but may not always be easily integrated into daily life. In many countries, hand cycling has become a serious option for daily mobility in people with tetraplegia. However, little information exists regarding the suitability of this exercise mode for this population.
Objective: The purpose of this study was to evaluate the effects of a structured hand cycle training program in individuals with chronic tetraplegia.
Design: Pretraining and posttraining outcome measurements of physical capacity were compared.
Setting: Structured hand cycle interval training was conducted at home or in a rehabilitation center in the Netherlands.
Participants: Twenty-two patients with tetraplegia (American Spinal Injury Association Impairment Scale classification A-D) at least 2 years since injury participated.
Intervention: The intervention was an 8- to 12-week hand cycle interval training program.
Measures: Primary outcomes of physical capacity were: peak power output (POpeak) and peak oxygen uptake (Vo2peak), as determined in hand cycle peak exercise tests on a motor-driven treadmill. Secondary outcome measures were: peak muscle strength (force-generating capacity) of the upper extremities (as assessed by handheld dynamometry), respiratory function (forced vital capacity and peak expiratory flow) and participant-reported shoulder pain.
Results: Significant improvements following a mean of 19 (SD=3) sessions of hand cycle training were found in POpeak (from 42.5 W [SD=21.9] to 50.8 W [SD=25.4]), Vo2peak (from 1.32 L·min−1 [SD=0.40] to 1.43 L·min−1 [SD=0.43]), and mechanical efficiency, as reflected by a decrease in submaximal oxygen uptake. Except for shoulder abduction strength, no significant effects were found on the secondary outcomes.
Limitations: Common health complications, such as urinary tract infections, bowel problems, and pressure sores, led to dropout and nonadherence.
Conclusion: Patients with tetraplegia were able to improve their physical capacity through regular hand cycle interval training, without participant-reported shoulder-arm pain or discomfort.
TL;DR: Four weeks of HIT improves 2000-m time-trial performance and relative Vo2peak in competitive rowers, more than a traditional approach.
Abstract: Purpose: Several recent studies have reported substantial performance and physiological gains in well-trained endurance runners, swimmers, and cyclists following a period of high-intensity interval training (HIT). The aim of the current study was to compare traditional rowing training (CT) to HIT in well-trained rowers. Methods: Subjects included 5 male and 5 female rowers (mean ± SD; age = 19 ± 2 y; height = 176 ± 8 cm; mass = 73.7 ± 9.8 kg; Vo2peak = 4.37 ± 1.08 L·min−1). Baseline testing included a 2000-m time trial and a maximal exercise test to determine Vo2peak, 4-min all-out power, and 4 mmol·L−1 blood lactate threshold. Following baseline testing, rowers were randomly allocated to HIT or CT, which they performed seven times over a 4-wk period. The HIT involved 8 × 2.5-min intervals at 90% of the velocity maintained at Vo2peak, with individual recoveries returning to 70% of the subjects’ maximal heart rate between intervals. The CT intensity consisted of workloads corresponding to 2 and 3 mmol·L−1 ...
TL;DR: Exercise training programmes seem to have a favourable effect on prognosis, even if the results of Heart Failure: a Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION) remain controversial, emphasizing the difficulty in monitoring observance and the importance of compliance with a long-term exercise training programme.
TL;DR: The effects of an 8-week exercise intervention on aerobic fitness, android and gynoid fat mass, and blood lipids in overweight and obese participants was examined.
Abstract: We examined the effects of an 8-week exercise intervention on aerobic fitness, android and gynoid fat mass, and blood lipids in overweight and obese participants. Twenty-four sedentary participants (average BMI = 30 +/- 2 kg/m(2); 18 females, 6 males) were randomized into either interval training and diet education (INT group), continuous aerobic exercise and diet education (CON group), or diet education only (DIET group). Durations of exercise sessions were similar ( approximately 30 minutes), with both exercise groups completing the same amount of work. The INT and CON groups demonstrated significant improvements over time for VO(2 peak) (p < 0.01 and p < 0.05, ES = 1.1 and 1.2, respectively) and time to exhaustion on a graded exercise test (p < 0.01 and ES = 0.8 for both groups). Further, a large effect size (0.7) was recorded for the loss in android fat mass over time in the INT group only.
TL;DR: Data demonstrate that the exercise-induced increase in plasma IL-6 concentration in response to customary exercise is attenuated by previous exercise training, and that this attenuation appears to occur independent of carbohydrate availability during training.
Abstract: This aims of this study were to investigate the effects of carbohydrate availability during endurance training on the plasma interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α response to ...
TL;DR: HIIT appeared to be the primary stimulus effecting EMGFT or EEA, suggesting adaptations from HIIT may be more influential than increasing skeletal muscle carnosine levels on delaying fatigue in recreationally active men.
Abstract: The purpose of this study was to determine the effects of beta-alanine supplementation and high-intensity interval training (HIIT) on electromyographic fatigue threshold (EMGFT) and efficiency of electrical activity (EEA). A total of 46 men completed four, 2-min work bouts on a cycle ergometer. Using bipolar surface electrodes, the EMG amplitude was averaged and plotted over the 2-min. The resulting slopes were used to calculate EMGFT and EEA. Following initial testing, all participants were randomly assigned to either placebo (PL; n = 18), beta-alanine (BA; n = 18) or control groups (CON; n = 10). Following randomization, participants engaged in 6 weeks of HIIT training. Significant improvements in EMGFT and EEA resulted for both training groups. In conclusion, HIIT appeared to be the primary stimulus effecting EMGFT or EEA, suggesting adaptations from HIIT may be more influential than increasing skeletal muscle carnosine levels on delaying fatigue in recreationally active men.
TL;DR: It was concluded that an 8-week program of high-intensity interval training is effective in eliciting favorable changes in HDL-C and TC/HDL-C but not TC in young adult men with normal TC levels.
Abstract: This study examined the impact of an 8-week program of high-intensity interval training on high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and the atherogenic index (TC/HDL-C) in 36 untrained men ages 21-36 years. Participants were randomly assigned to an interval training group (n = 20) or a control group (n = 16). Participants in the experimental group performed 3.2 km of interval running (1:1 work:rest ratio) 3 times a week for 8 weeks at an intensity of 90% of maximal heart rate (~423 kcal per session). Results indicated significant pre- to posttraining changes in HDL-C (1.1 vs. 1.3 mmol·L-1, p 0.05) with interval training. It was concluded that an 8-week program of high-intensity interval training is effective in eliciting favorable changes in HDL-C and TC/HDL-C but not TC in young adult men with normal TC levels. Our findings support the recommendations of high-intensity interval training as an alternative mode of exercise to improve blood lipid profiles for individuals with acceptable physical fitness levels
TL;DR: It is suggested that Cr supplementation may enhance the effects of intense interval endurance training on endurance performance changes, and CP and AWC were not affected.
Abstract: The critical power test provides 2 measures, critical power (CP) and anaerobic working capacity (AWC). In theory, the CP measurement represents the maximal power output that can be maintained without fatigue, and AWC is an estimate of work capacity associated with muscle energy reserves. High-intensity interval training (HIIT) has been shown to be an effective training method for improving endurance performance, including VO2PEAK. In addition, creatine (Cr) supplementation has been reported to improve AWC without training; however, it has shown no effect on CP. The purpose of this study was to examine the effects of 4 weeks of HIIT with Cr supplementation on CP and AWC. Forty-two recreationally active men volunteered to participate in this study. Participants were randomly assigned to 1 of 3 groups: Cr (n = 16), 10 g Cr + 10 g dextrose; placebo (PL, n = 16), 20 g dextrose; control (CON, n = 10), no treatment. Before and after supplementation, each participant performed a maximal oxygen consumption test VO2PEAK on a cycle ergometer to establish peak power output (PPO). Participants then completed a CP test involving 3 exercise bouts with the workloads set as a percentage of their PPO to determine CP and AWC. After a 2-week familiarization period of training and supplementing, PPO, CP, and AWC were remeasured before an additional 4 weeks of HIIT and supplementation were completed. Training consisted of 5 sets of 2-minute exercise bouts with 1 minute rest in between performed on the cycle ergometer, with intensities based on PPO. A significant improvement in CP was observed in the Cr group (6.72% +/- 2.54%), whereas PL showed no significant change (3.87% +/- 2.30%), and CON significantly decreased (6.27% +/- 2.38%). Furthermore, no changes in AWC were observed in any of the groups after treatment. The current findings suggest that Cr supplementation may enhance the effects of intense interval endurance training on endurance performance changes.
TL;DR: Local ice therapy immediately following sprint-interval training was associated with greater decreases in both pro- and anti-inflammatory cytokines and anabolic hormones supporting some clinical evidence for possible negative effects on athletic performance.
Abstract: We evaluated the effect of cold ice-pack application following a brief sprint-interval training on the balance between anabolic mediators [growth hormone (GH), insulin-like growth factor-I (IGF-I), testosterone], catabolic markers (cortisol, IGFBP-1), and circulating pro [Interlukin-6 (IL-6) and IL-1β]- and anti-inflammatory cytokines [IL-1 receptor antagonist (IL-1ra)]. Twelve males, elite junior handball players performed 4 × 250 m treadmill run, at 80% of each individual’s maximal speed, followed by a rest period with and without local cold-pack application. Pre, immediately post, and 60-min post-exercise blood samples were drawn. Exercise was associated with a significant increase in IL-6, GH, IGFBP-3, and testosterone levels. Local cold-pack application was associated with significant decreases in IL-1β, IL-1ra, IGF-I, and IGFBP-3 and a greater increase of IGFBP-1 during recovery. Local ice therapy immediately following sprint-interval training was associated with greater decreases in both pro- and anti-inflammatory cytokines and anabolic hormones supporting some clinical evidence for possible negative effects on athletic performance.
TL;DR: It is demonstrated that, when the duration of exercise and work performed is the same, IE and CE influence the transcription of genes involved in oxidative metabolism in a similar manner.
Abstract: Purpose: There is a debate whether interval or traditional endurance training is the most effective stimulus of mitochondrial biogenesis. Here, we compared the effects of acute interval exercise (I ...
TL;DR: The data demonstrate that females did not respond to continuous or interval training in terms of increasing HSP content of the vastus lateralis muscle, while males displayed HSP adaptations to both training interventions.
Abstract: This study investigates the effects of short-term endurance training on heat shock protein (HSP) adaptations of male and female human skeletal muscle. The data demonstrate that females did not respond to continuous or interval training in terms of increasing HSP content of the vastus lateralis muscle. In contrast, males displayed HSP adaptations to both training interventions. These data provide a platform for future human studies to examine a potential gender-specific stress response to exercise.
TL;DR: Compared with CT, IT was well tolerated and produced similar improvements in exercise performance and quality of life.
Abstract: PURPOSE The purpose of this study was to compare the effects of interval training (IT) and continuous steady-pace training (CT) in patients with COPD. METHODS Patients (n = 21) (mean forced expiratory volume in 1 second ([FEV1] = 44.6% +/- 13.9%) were randomized to IT, and 20 patients (mean FEV1 = 41.7% +/- 12.6%) to CT. Outcome measures included 6-minute walk distance, maximal work capacity, endurance exercise time during constant workload exercise at 60% to 70% of maximal work capacity, and quality of life including fatigue and dyspnea. Participants exercised 3 times per week for 8 weeks, and total work was the same for both training regimens. RESULTS Significant improvement in mean score was observed in each variable within each of the 2 groups: 6-minute walk distance (IT = 158 +/- 178 ft, CT = 106 +/- 165 ft); maximal work capacity (IT = 10.0 +/- 13.0 W, CT = 11.5 +/- 13.1 W); endurance exercise time (IT = 15.0 +/- 12.5 minutes, CT = 18.7 +/- 10.6 minutes); and quality of life domains, fatigue (IT = 3.1 +/- 3.0, CT = 2.8 +/- 4.7), and dyspnea (IT = 4.4 +/- 5.3, CT = 5.4 +/- 5.1). There was no significant difference in the extent of improvement between the 2 training regimens for any of the outcome variables. CONCLUSION Compared with CT, IT was well tolerated and produced similar improvements in exercise performance and quality of life.
TL;DR: Based on the results of the single Wingate test, nonlinear measures, such as HR complexity, may be more sensitive in detecting subtle alterations in neurocardiac behaviour, compared with traditional measures of HR variability.
Abstract: Sprint interval training involves short bouts of high-intensity exercise and has produced training responses similar to those of endurance training. The effects of multiple supramaximal exercise bo...
TL;DR: It is suggested that interval-type physical activity was more reinforcing than continuous constant-load physical activity for children when exercising both >VT and
TL;DR: This work has shown that regular physical exercise is the most appropriate to improve aerobic capacity, but its effect still remained discussed in old people.
Abstract: Summary
Background: Ageing is known to be associated with a decrease in peak oxygen consumption (VO2peak) and maximal tolerated power (MTP). Regular physical exercise is the most appropriate to improve aerobic capacity, but its effect still remained discussed in old people.
Design: The aim of this study was to determine whether a short interval training session would be associated with improvements in exercise efficiency in aged subjects in both genders.
Methods: In all, 19 women and 16 men (65.4 ± 4.9 years) performed a cycle incremental exercise test before and after a 9-week period of aerobic interval training (twice a week, 30 min session where 6 × 4-min at the first ventilatory threshold alternated with 1-min at the second ventilatory threshold) with cycle ergometer. Minute ventilation (MV), O2 uptake (VO2) and CO2 output (VCO2) were measured breath-by-breath and by an open-circuit metabolic cart.
Results: Before training, maximal values of MV (MMV), VO2peak, heart rate, systolic blood pressure, MTP, blood lactate at MTP recovery and the power at the first (pVT1) and second ventilatory thresholds (pVT2) were higher in men compared with women. Nine weeks of interval training induced a significant increase in MMV, VO2peak, MTP, pVT1 and pVT2 and decrease in systolic blood pressure in the same way in men than in women, without any significant effect on their maximal heart rate values.
Conclusions: These findings suggest that the age-related declines in aerobic index are attenuated by a short exercise interval training sessions in women and men.
TL;DR: HIIT is an effective and time-efficient way to improve maximal endurance performance and creatine supplementation does not seem to further augment maximal oxygen consumption, greater than HIIT alone; however, Cr supplementation may improve submaximal exercise performance.
Abstract: High-intensity interval training has been shown to be a time-efficient way to induce physiological adaptations similar to those of traditional endurance training. Creatine supplementation may enhance high-intensity interval training, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of high-intensity interval training (HIIT) and creatine supplementation on cardiorespiratory fitness and endurance performance (maximal oxygen consumption (VO2PEAK), time-to-exhaustion (VO2PEAKTTE), ventilatory threshold (VT), and total work done (TWD)) in college-aged men. Forty-three recreationally active men completed a graded exercise test to determine VO2PEAK, VO2PEAKTTE, and VT. In addition, participants completed a time to exhaustion (TTE) ride at 110% of the maximum workload reached during the graded exercise test to determine TWD (TTE (sec) × W = J). Following testing, participants were randomly assigned to one of three groups: creatine (creatine citrate) (Cr; n = 16), placebo (PL; n = 17), or control (n = 10) groups. The Cr and PL groups completed four weeks of HIIT prior to post-testing. Significant improvements in VO2PEAK and VO2PEAKTTE occurred in both training groups. Only the Cr group significantly improved VT (16% vs. 10% improvement in PL). No changes occurred in TWD in any group. In conclusion, HIIT is an effective and time-efficient way to improve maximal endurance performance. The addition of Cr improved VT, but did not increase TWD. Therefore, 10 g of Cr per day for five days per week for four weeks does not seem to further augment maximal oxygen consumption, greater than HIIT alone; however, Cr supplementation may improve submaximal exercise performance.
TL;DR: The findings suggest that critical speed represents a transition point between two different sets of stroke parameter relationships – one for low-intensity aerobic swimming and one for high-intensity anaerobic swimming.
Abstract: The aim of this study was to determine whether a relationship exists between stroke parameters and critical swimming speed (which is defined as the speed that can theoretically be maintained without exhaustion). Stroke parameters (stroke rate and length) and velocity were recorded for each 25-m length during a controlled sprint interval training set in which participants swam one of the four competitive strokes at a range of intensities below, at, and above critical speed. Eleven participants (8 females, 3 males; age 17.9 ± 0.9 years) completed a progressive (descending) set of 8 × 100 m repetitions in a 25-m pool according to target times that ranged in intensity from 65% to 100% of the swimmer's best time (the intensity for each repetition increased by 5% throughout the set). The data showed that participants reached critical speed on the fourth repetition and that substantial and unpredictable changes in stroke parameters occurred once critical speed had been reached. Specifically, post-critic...
TL;DR: Results show no benefit of WBV on running performance recovery following a HIIT session, and it is shown that there may be acute alterations in metabolism 24 h following such a running session in well-trained, middle-aged runners.
Abstract: The main purpose of the present study was to examine the effects of acute whole body vibration (WBV) on recovery following a 3 km time trial (3 km TT) and high-intensity interval training (HIIT) (8 x 400 m). Post-HIIT measures included 3 km time-trial performance, exercise metabolism and markers of muscle damage (creatine kinase, CK) and inflammation (c-reactive protein, CRP). A second purpose was to determine the effects of a 3 km TT and HIIT on performance and metabolism the following day. Nine well-trained, middle-aged, male runners [(mean +/- SD) age 45 +/- 6 years, body mass 75 +/- 7 kg, VO2peak 58 +/- 5 ml kg(-1 )min(-1)] performed a constant pace run at 60 and 80% velocity at VO2peak (v VO2peak) followed by a 3-km TT and a 8 x 400-m HIIT session on two occasions. Following one occasion, the athletes performed 2 x 15 min of low frequency (12 Hz) WBV, whilst the other occasion was a non-WBV control. Twenty-four hours after each HIIT session (day 2) participants performed the constant pace run (60 and 80% v VO2peak) and 3 km TT again. There was a significant decrease in 3 km TT performance (~10 s) 24 h after the HIIT session (P 0.05). Creatine kinase was significantly elevated on day 2, though there were no differences between conditions (P > 0.05). VO2peak and blood lactate were lower on day 2 (P 0.05). These results show no benefit of WBV on running performance recovery following a HIIT session. However, we have shown that there may be acute alterations in metabolism 24 h following such a running session in well-trained, middle-aged runners.