Sprint Interval Training Group Research Articles

Eight weeks of high-intensity interval vs. sprint interval training effects on overweight and obese adolescents carried out during the cool-down period of physical education classes: randomized controlled trial.

The aim of this study was to evaluate the effect of sprint interval training (SIT) and [high intensive interval training (HIIT)] carried out during the cool-down period of the physical education classes on body composition, blood pressure variables (BP) and pulse rate (PR), and cardiorespiratory fitness of adolescents who are overweight and obese, and to compare the differences in enjoyment in response to SIT vs. HIIT. For this randomized controlled trial, forty-five adolescents were recruited from a high school and were randomly placed into three groups. SIT and HIIT trained for 8 weeks, twice a week, for 12 min/session. Experimental group (EG) 3 was the control, and they maintained their regular physical education class schedule. The SIT group performed 6 sets of 60 s of work (90-95%HRmax) / 60 s of rest (50-55%HRmax), and the HIIT group performed 3 sets of 2 min of work (80-85%HRmax) / 2 min of rest (50-55%HRmax). Both experimental groups showed a significant improvement in fat mass (FM) (%) and trunk FM (kg). In addition, EG2 reported a significance improvement in lean mass (kg), blood pressure BP (mmHG), systolic blood pressure (SBP) (mmHg), diastolic blood pressure (DBP) (mmHg), PR (bpm), and VO2max (ml/kg/min). The present study found that a HIIT protocol performed during the cool-down period of the physical education classes generated adaptations such as improvement in body composition, BP variables and PR, and cardiorespiratory fitness, in overweight and obese adolescents. In contrast, the group of overweight and obese adolescents who performed SIT showed limited benefits, with changes in fat mass only.

Five Weeks of Sprint Interval Training Improve Muscle Glycolytic Content and Activity But Not Time to Task Failure in Severe-Intensity Exercise.

This study examined the impact of a 5-wk sprint interval training (SIT) intervention on time to task failure (TTF) during severe-intensity constant work rate (CWR) exercise, as well as in glycolytic enzymatic content and activity, and glycogen content. Fourteen active males were randomized into either a SIT group ( n = 8) composed of 15 SIT sessions over 5 wk, or a control group ( n = 6). At pretraining period, participants performed i) ramp incremental test to measure the cardiorespiratory function; ii) CWR cycling TTF at 150% of the power output (PO) at the respiratory compensation point (RCP-PO) with muscle biopsies at rest and immediately following task failure. After 5 wk, the same evaluations were repeated (i.e., exercise intensities matched to current training status), and an additional cycling CWR matched to pretraining 150% RCP-PO was performed only for TTF evaluation. The content and enzymatic activity of glycogen phosphorylase (GPhos), hexokinase (HK), phosphofructokinase (PFK), and lactate dehydrogenase (LDH), as well as the glycogen content, were analyzed. Content of monocarboxylate transporter isoform 4 (MCT4) and muscle buffering capacity were also measured. Despite improvements in total work performed at CWR posttraining, no differences were observed for TTF. The GPhos, HK, PFK, and LDH content and activity, and glycogen content also improved after training only in the SIT group. Furthermore, the MCT4 concentrations and muscle buffering capacity were also improved only for the SIT group. However, no difference in glycogen depletion was observed between groups and time. Five weeks of SIT improved the glycolytic pathway parameters and total work performed; however, glycogen depletion was not altered during CWR severe-intensity exercise, and TTF remained similar.

The impact of sprint interval training versus moderate intensity continuous training on blood pressure and cardiorespiratory health in adults: a systematic review and meta-analysis.

Although aerobic exercise is the primary modality recommended for the treatment of hypertension, it remains unclear whether high-intensity all-out sprint interval training (SIT) can result in greater reductions of blood pressure (BP) and cardiorespiratory health. This systematic review aims to compare the impact of SIT versus Moderate-intensity continuous training (MICT) on improvements in resting systolic blood pressure (SBP), diastolic blood pressure (DBP) and maximal oxygen uptake (VO2 max) among adults. We conducted a systematic search of three online databases (PubMed, Embase, and Web of Science) from January 2000 to July 2023 to identify randomized controlled trials that compared the chronic effects of SIT versus MICT on BP in participants with high or normal blood pressure. We extracted information on participant characteristics, exercise protocols, BP outcomes, and intervention settings. Furthermore, the changes in VO2 max between the two groups were analyzed using a meta-analysis. The pooled results were presented as weighted means with 95% confidence intervals (CI). Out of the 1,874 studies initially were found, eight were included in this review, totaling 169 participants. A significant decrease in SBP (MD = -2.82 mmHg, 95% CI [-4.53 to -1.10], p=0.08, I2 =45%) was observed in the SIT group compared to before the training, but no significant decrease in DBP (MD = -0.75 mmHg, 95% CI [-1.92 to 0.42], p=0.16, I2 = 33%) was observed. In contrast, both SBP (MD = -3.00 mmHg, 95% CI [-5.31 to -0.69], p=0.68, I2 = 0%) and DBP (MD = -2.11 mmHg, 95% CI [-3.63 to -0.60], p=0.72, I2 = 0%) significantly decreased in the MICT group with low heterogeneity. No significant difference was found in resting SBP and DBP between SIT and MICT after the intervention. Both SIT and MICT significantly increased VO2 peak, with SIT resulting in a mean difference (MD) of 1.75 mL/kg/min (95% CI [0.39-3.10], p=0.02, I2 = 61%), and MICT resulting in a mean difference of 3.10 mL/kg/min (95% CI [1.03-5.18], p=0.007, I2 = 69%). MICT was more effective in improving VO2 peak (MD = -1.36 mL/kg/min, 95% CI [-2.31 to 0.40], p=0.56, I2 = 0%). Subgroup analysis of duration and single sprint time showed that SIT was more effective in reducing SBP when the duration was ≥8 weeks or when the sprint time was <30 s. Our meta-analysis showed that SIT is an effective intervention in reducing BP and improving cardiorespiratory fitness among adults. Consequently, SIT can be used in combination with traditional MICT to increase the variety, utility, and time efficiency of exercise prescriptions for different populations.

Physiological and Performance Adaptations to Interval Training in Endurance-Trained Cyclists: An Exploratory Systematic Review and Meta-Analysis

Background: In endurance cycling, both high-intensity interval training (HIIT) and sprint interval training (SIT) have become popular training modalities due to their ability to elicit improvements in performance. Studies have attempted to ascertain which form of interval training might be more beneficial for maximising cycling performance as well as a range of physiological parameters, but an amalgamation of results which explores the influence of different interval training programming variables in trained cyclists has not yet been conducted.&#x0D; Objective: The aims of this study were to: (1) systematically investigate training interventions to determine which training modality, HIIT, SIT or low- to moderate-intensity continuous training (LIT/MICT), leads to greater physiological and performance adaptations in trained cyclists; and (2) determine the moderating effects of interval work-bout duration and intervention length on the overall HIIT/SIT programme.&#x0D; Data Sources: Electronic database searches were conducted using SPORTDiscus and PubMed.&#x0D; Study Selection: Inclusion criteria were: (1) at least recreationally-trained cyclists aged 18–49 years (maximum/peak oxygen uptake [V̇O2max/V̇O2peak] ≥45 mL·kg-1·min-1); (2) training interventions that included a HIIT or SIT group and a control group (or two interval training groups for direct comparisons); (3) minimum intervention length of 2 weeks; (4) interventions that consisted of 2–3 weekly interval training sessions­.&#x0D; Results: Interval training leads to small improvements in all outcome measures combined (overall main effects model, SMD: 0.33 [95%CI = 0.06 to 0.60]) when compared to LIT/MICT in trained cyclists. At the individual level, point estimates favouring HIIT/SIT were negligible (Wingate model: 0.01 [95%CI = -3.56 to 3.57]), trivial (relative V̇O2max/V̇O2peak: 0.10 [95%CI = -0.34 to 0.54]), small (absolute V̇O2max/V̇O2peak: 0.28 [95%CI = 0.15 to 0.40], absolute maximum aerobic power/peak power output: 0.38 [95%CI = 0.15 to 0.61], relative absolute maximum aerobic power/peak power output: 0.43 [95%CI = -0.09 to 0.95], physiological thresholds: 0.46 [95%CI = -0.24 to 1.17]), and large (time-trial/time-to-exhaustion: 0.96 [95%CI = -0.81 to 2.73]) improvements in physiological/performance variables compared to controls, with very imprecise interval estimates for most outcomes. In addition, intervention length did not contribute significantly to the improvements in outcome measures in this population, as the effect estimate was only trivial (βDuration: 0.04 [ 95%CI = -0.07 to 0.15]). Finally, the network meta-analysis did not reveal a clear superior effect of any HIIT/SIT types when directly comparing interval training differing in interval work-bout duration.&#x0D; Conclusion: The results of the meta-analysis indicate that both HIIT and SIT are effective training modalities to elicit physiological adaptations and performance improvements in trained cyclists. Our analyses highlight that the optimisation of interval training prescription in trained cyclists cannot be solely explained by interval type or interval work-bout duration and an individualised approach that takes into account the training/competitive needs of the athlete is warranted.

Aerobic high-intensity intervals improve V̇O2max more than supramaximal sprint intervals in females, similar to males.

Maximal oxygen uptake (V̇O2max ) is a pivotal factor for aerobic endurance performance. Recently, aerobic high-intensity interval training (HIIT) was documented to be superior to sprint interval training (SIT) in improving V̇O2max in well-trained males. However, as mounting evidence suggests that physiological responses to training are sex-dependent, examining the effects of HIIT versus SIT on V̇O2max , anaerobic capacity, and endurance performance in females is warranted. We randomized 81 aerobically well-trained females (22 ± 2 years, 51.8 ± 3.6 mL∙kg-1 ∙min-1 V̇O2max ), training three times weekly for 8 weeks, to well-established protocols: (1) HIIT 4 × 4 min at ~95% of maximal aerobic speed (MAS), with 3 min active recovery (2) SIT 8 × 20 s at ~150% of MAS, with 10 s passive recovery (3) SIT 10 × 30 s at ~175% of MAS, with 3.5 min active recovery. Only HIIT 4 × 4 min increased V̇O2max (7.3 ± 3.1%), different from both SIT groups (all p < 0.001). Anaerobic capacity (maximal accumulated oxygen deficit) increased following SIT 8 × 20 s (6.5 ± 10.5%, p < 0.05), SIT 10 × 30 s (14.4 ± 13.7%, p < 0.05; different from HIIT 4 × 4 min, p < 0.05). SIT 10 × 30 s resulted in eight training-induced injuries, different from no injuries following HIIT 4 × 4 min and SIT 8 × 20 s (p < 0.001). All groups improved long-distance (3000-meter) and sprint (300-meter) running performance (all p < 0.001). SIT protocols improved sprint performance more than HIIT 4 × 4 min (p < 0.05). Compared to previous male results, no increase in V̇O2max following SIT 8 × 20 s (p < 0.01), and a higher injury rate for SIT 10 × 30 s (p < 0.001), were evident. In aerobically well-trained women, HIIT is superior to SIT in increasing V̇O2max while all-out treadmill running SIT is potentially more harmful.

Serum Osteocalcin, Sclerostin and Lipocalin-2 Levels in Adolescent Boys with Obesity over a 12-Week Sprint Interval Training.

The aim of the study was to examine the effects of supervised cycling sprint interval training (SIT) on serum osteocalcin, lipocalin-2 and sclerostin levels, and bone mineral characteristics among obese adolescent boys. Untrained obese adolescent boys aged 13.4 ± 0.3 were assigned to either a 12-week SIT group (3 sessions/week), or a non-exercising control group who continued with their habitual everyday life. Serum osteocalcin, lipocalin-2 and sclerostin concentrations, and bone mineral values were assessed before and after intervention. After 12-week intervention, where 14 boys in both groups ended the study, there were no significant differences in serum osteokine levels between the groups after 12 weeks, while whole body bone mineral content and lower limb bone mineral density increased in the SIT group (p < 0.05). Change in body mass index was negatively correlated with the change in osteocalcin (r = -0.57; p = 0.034), and positively correlated with the change in lipocalin-2 levels (r = 0.57; p = 0.035) in the SIT group. Supervised 12-week SIT intervention improved bone mineral characteristics, but did not change osteocalcin, lipocalin-2 or sclerostin levels in adolescent boys with obesity.

Two weeks of arm cycling sprint interval training enhances spinal excitability to the biceps brachii.

The present study aimed to investigate whether a 2-wk arm cycling sprint interval training (SIT) program modulated corticospinal pathway excitability in healthy, neurologically intact participants. We employed a pre-post study design with two groups: 1) an experimental SIT group and 2) a nonexercising control group. Transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid electrical stimulation (TMES) of corticospinal axons were used at baseline and post-training to provide indices of corticospinal and spinal excitability, respectively. Stimulus-response curves (SRCs) recorded from the biceps brachii were elicited for each stimulation type during two submaximal arm cycling conditions [25 watts (W) and 30% peak power output (PPO)]. All stimulations were delivered during the mid-elbow flexion phase of cycling. Compared with baseline, performance on the time-to-exhaustion (TTE) test at post-testing was improved for members of the SIT group but was not altered for controls, suggesting that SIT improved exercise performance. There were no changes in the area under the curve (AUC) for TMS-elicited SRCs for either group. However, the AUC for TMES-elicited cervicomedullary motor-evoked potential SRCs were significantly larger at post-testing in the SIT group only (25 W: P = 0.012, d = 0.870; 30% PPO: P = 0.016, d = 0.825). This data shows that overall corticospinal excitability is unchanged following SIT, whereas spinal excitability is enhanced. Although the precise mechanisms underlying these findings during arm cycling at post-SIT are unknown, it is suggested that the enhanced spinal excitability may represent a neural adaptation to training.NEW & NOTEWORTHY Two weeks of arm cycling sprint interval training (SIT) improves subsequent aerobic exercise performance and induces changes within the descending corticospinal pathway. Specifically, spinal excitability is enhanced following training, whereas overall corticospinal excitability does not change. These results suggest that the enhanced spinal excitability may represent a neural adaptation to training. Future work is required to discern the precise neurophysiological mechanisms underlying these observations.

Effect of supervised sprint interval training on cardiorespiratory fitness and body composition in adolescent boys with obesity

ABSTRACT This study examined the effect of a supervised 12-week sprint interval training (SIT) on cardiorespiratory fitness (CRF) and body composition in adolescent boys with obesity. Twenty-eight adolescents with obesity were allocated to either an intervention group (SIT) (13.1 ± 0.3 yrs; body mass index [BMI]: 30.3 ± 0.9 kg.m−2) or a control group (CONT) (13.7 ± 0.4 yrs; BMI: 32.6 ± 1.6 kg.m−2). The SIT group performed 4–6 × 30s “all-out” cycling bouts, interspersed with 4 min of recovery 3 days a week for 12 weeks. CRF was measured by direct peak oxygen consumption (VO2peak) defined as VO2peak per kg of body mass (mL.min−1kg−1) or by VO2peak per kg of lean body mass (mL.min−1LBM−1) and body composition was assessed by dual-energy X-ray absorptiometry. SIT intervention led to a significant and large between-group difference in VO2peak (p = 0.004; η2 = 0.29). Although SIT group had a significant reduction in body fat percentage (BF%) (from 41.1 ± 1.3% to 39.2 ± 1.5%; p = 0.006), there were no between-group differences in the change of the pre- and post-measures in BF% (p = 0.067). In conclusion, 12-week SIT is effective in increasing CRF and decreasing BF% in adolescent boys with obesity.

The Effect Of Eight-week Sprint Interval Training On Aerobic Ability Of Elite Female Badminton Players

Because of the fast ball speed, high swing frequency and short intervals, the badminton event requires athletes to complete fast running, sudden start or stop, change of direction and continuous high-intensity multiple shots on the field. There are high requirements for athletes' aerobic capacity. PURPOSE: The purpose of this study is to explore the effect of 8-week Sprint Interval Training (SIT) on enhancing the aerobic exercise ability of female badminton athletes from the perspective of oxygen transport and utilization. METHODS: Sixteen elite female badminton players were selected and random divided into experimental group (SIT group) and control group (CON group). The SIT group underwent three sprint interval trainings per week, including two power bike trainings and one multi-ball training. The CON group performed two Fartlek runs and one regular shuttlecock-feeding training per week for a total of eight weeks. Before and after intervention, the two groups of athletes were tested for aerobic capacity via YO-YO IR2, maximal oxygen uptake, lactate clearance rate, and the arterial occlusion muscle oxygen content test performed by Near Infrared Spectroscopy (NIRS) instrument. Subsequently, players' muscle oxygen consumption and other related parameters were compared between two groups using repeated-measures ANOVA, considering pre-post effect. RESULTS: The running distance of YO-YO IR2 of SIT group increased from 725 ± 132.9 m to 840 ± 126.5 m (p < 0.05). The VT-VO2 of SIT group increased from 1940.1 ± 112.8 ml/min to 2176.9 ± 78.6 ml/min (p < 0.05), VT/VO2max increased from 75 ± 4% to 82 ± 4% (p < 0.05), and the lactate clearance rate was raised from 21 ± 5% to 27 ± 4% (p < 0.05). The ΔO2Hb of SIT group decreased from 4.8 ± 0.5 μm to 4.4 ± 0.5 μm (p < 0.05), the oxygen consumption of muscle decreased from 0.62 ± 0.06 mlO2/min/100 g to 0.57 ± 0.06 mlO2/min/100 g (p < 0.05), and the full recovery time of O2Hb declined from 9.99 ± 1.9 s to 9.44 ± 1.5 s (p < 0.05), O2Hb over-recovery increased from 4.79 ± 0.5 μm to 5.19 ± 0.6 μm (p < 0.05). CONCLUSIONS: SIT can improve maximum aerobic working capacity, aerobic recovery ability and oxygen utilization efficiency by improving the oxygen uptake and utilization ability of badminton players’ skeletal muscles, thus boosting the their rapid repeated sprinting ability.

The Effect of Traditional Aerobic Exercise and Sprint Interval Training on Insulin Resistance in Men With Prediabetes: A Randomised Controlled Trial.

IntroductionPrediabetes is an intermediate stage with hyperglycaemia below the threshold of diabetes mellitus. Insulin resistance is a significant factor in its pathogenesis. Lifestyle modifications are suggested and found to be more beneficial in this stage. Moderate-intensity exercise for 30 to 45 minutes a day is routinely recommended but has low compliance, and lack of time is a significant deterrent. Sprint interval training (SIT) is an alternate exercise regimen with higher intensity and less time requirement. The present study compares the effect of a three-month intervention of traditional aerobic exercise and sprint interval training on insulin resistance in prediabetic men.MethodsThe study subjects were males aged 25 to 40 years with prediabetes as per the American Diabetes Association criteria of fasting and two-hour plasma glucose levels. The study is a parallel-group randomised trial with one arm (AE group) involved in the traditional aerobic exercise (brisk walking) for 30 minutes, five days a week. The other arm was the sprint interval training (SIT) group performing an ‘all-out’ run effort for one minute followed by a recovery rest period of one and a half minutes, completing one cycle of two and half minutes. Four such cycles were completed in each session. Thus, the exercise sessions were just 10 minutes daily, three days a week. The duration of the intervention was three months. One hundred and sixty participants were recruited after screening and randomly assigned in a 1:1 ratio to the two groups. The primary outcome measure was insulin resistance estimated by homeostasis model assessment -estimated insulin resistance (HOMA-IR). The secondary outcome measures were fasting plasma glucose and serum insulin, glycated haemoglobin, body mass index and waist-hip ratio.ResultsThe mean age of the AE group was 30.7 ± 3.3 years, and the SIT group was 31 ± 3.4 years. Seventy-two men from the AE group and 74 from the SIT group completed the study. After the three-month AE and SIT exercise, the per-protocol analysis reflected a significant reduction in insulin resistance, i.e., HOMA-IR (3.6 ± 1.1 to 3 ± 1.2, p<0.0001) after traditional aerobic exercise. Similarly, the HOMA-IR was significantly reduced after sprint interval training (3.3 ± 1.2 to 2.5 ± 1, p<0.0001). The intention-to-treat analysis also found that the reductions in HOMA-IR after both exercise protocols were statistically significant. The change in insulin resistance compared for the SIT vs AE group was not statistically significant. Secondary outcome measures HbA1c, fasting glucose, fasting insulin, BMI, and waist-hip ratio showed significant improvement with AE and SIT. ConclusionsThe sprint interval training similarly improved insulin resistance and other parameters compared to the traditional exercise group. SIT can be a time-efficient exercise protocol suggested as a part of lifestyle modification for men with prediabetes.

Exercise Is Medicine…and the Dose Matters.

The cellular events underpinning exercise adaptation have long been studied since Holloszy's novel findings in rodents over 50 years ago (Holloszy, 1967). Contemporary advances in laboratory techniques have allowed researchers to further explore physiological adaptations to physical activity, and much attention has been given to elucidating the distinct biochemical responses to exercise of varying intensities. More specifically, comparison of high intensity interval training (HIIT) or sprint interval training (SIT), to moderate intensity continuous training (MICT) has been an area of great interest among exercise physiologists. Spearheading these investigations, Burgomaster and colleagues provided evidence for robust and comparable metabolic adaptations when 6-weeks of low-volume SIT was pitted against conventional MICT, despite markedly reduced total training volume in the SIT group (66% less time, 90% less energy expenditure) (Burgomaster et al., 2008). Follow-up studies supporting these findings have provided continued enthusiasm for HIIT/SIT as a time-efficient strategy to improve cardiometabolic health (Gillen and Gibala, 2014; Gillen et al., 2016; Wolfe et al., 2020). HIIT has since become one of the most popular fitness trends as reported by the American College of Sports Medicine (ACSM) (#5 in 2021 survey) (Thompson, 2021). While we acknowledge these findings and are advocates for HIIT, we feel as though it is also important to appreciate the discrepant nature of HIIT and MICT, which may foster unique physiological adaptations with relevant health implications. Few, if any of these adaptations are mutually exclusive, but their magnitude may vary in a manner that should be considered to when determining exercise prescription.

The Effect of Eight-Week Sprint Interval Training on Aerobic Performance of Elite Badminton Players.

This study was aimed to: (1) investigate the effects of physiological functions of sprint interval training (SIT) on the aerobic capacity of elite badminton players; and (2) explore the potential mechanisms of oxygen uptake, transport and recovery within the process. Thirty-two elite badminton players volunteered to participate and were randomly divided into experimental (Male-SIT and Female-SIT group) and control groups (Male-CON and Female-CON) within each gender. During a total of eight weeks, SIT group performed three times of SIT training per week, including two power bike trainings and one multi-ball training, while the CON group undertook two Fartlek runs and one regular multi-ball training. The distance of YO-YO IR2 test (which evaluates player’s ability to recover between high intensity intermittent exercises) for Male-SIT and Female-SIT groups increased from 1083.0 ± 205.8 m to 1217.5 ± 190.5 m, and from 725 ± 132.9 m to 840 ± 126.5 m (p < 0.05), respectively, which were significantly higher than both CON groups (p < 0.05). For the Male-SIT group, the ventilatory anaerobic threshold and ventilatory anaerobic threshold in percentage of VO2max significantly increased from 3088.4 ± 450.9 mL/min to 3665.3 ± 263.5 mL/min (p < 0.05),and from 74 ± 10% to 85 ± 3% (p < 0.05) after the intervention, and the increases were significantly higher than the Male-CON group (p < 0.05); for the Female-SIT group, the ventilatory anaerobic threshold and ventilatory anaerobic threshold in percentage of VO2max were significantly elevated from 1940.1 ± 112.8 mL/min to 2176.9 ± 78.6 mL/min, and from 75 ± 4% to 82 ± 4% (p < 0.05) after the intervention, which also were significantly higher than those of the Female-CON group (p < 0.05). Finally, the lactate clearance rate was raised from 13 ± 3% to 21 ± 4% (p < 0.05) and from 21 ± 5% to 27 ± 4% for both Male-SIT and Female-SIT groups when compared to the pre-test, and this increase was significantly higher than the control groups (p < 0.05). As a training method, SIT could substantially improve maximum aerobic capacity and aerobic recovery ability by improving the oxygen uptake and delivery, thus enhancing their rapid repeated sprinting ability.

Four Minutes of Sprint Interval Training Had No Acute Effect on Improving Alertness, Mood, and Memory of Female Primary School Children and Secondary School Adolescents: A Randomized Controlled Trial.

We investigated whether a 4-min sprint interval training (SIT) protocol had an acute effect (15 min after) on improving alertness, mood, and memory recall in female students. Sixty-three children and 131 adolescents were randomly assigned to either a SIT or control (CON) group by the class Physical Education (PE) teachers. The SIT intervention was delivered twice a week for 3 weeks. SIT participants performed three, 20-s ‘all-out’ effort sprints interspersed with 60-s intervals of walking while CON group sat down and rested. PE lessons were arranged such that the first two sessions were to familiarise participants with the SIT protocol leading to acute assessments conducted on the third session. On that occasion, both groups rated their alertness and mood on a single-item hedonic scale and underwent an adapted memory recall test. The same assessments were administered to both groups fifteen minutes after delivery of SIT intervention. A 4-min SIT involving three, 20 s ‘all-out’ effort intensity sprints did not have an acute main effect on improving alertness, mood and, memory recall in female children (ηp2 = 0.009) and adolescents (ηp2 = 0.012). Students’ exercise adherence and feedback from PE teachers are indicatives of the potential scalability of incorporating SIT into PE programmes. Different work-to-rest ratios could be used in future studies.

Intellectual disability, exercise and aging: the IDEA study: study protocol for a randomized controlled trial

BackgroundPeople with intellectual disabilities (ID) have low levels of physical activity (PA) together with accelerated aging profiles. Adherence to PA interventions for persons with ID is low based on barriers such as motivation. The IDEA study aims to determine the effect of two types of exercise programs, continuous aerobic (CAEP) vs sprint interval training (SIT), designed for seniors with ID on health-related physical fitness, cardiovascular parameters, quality of life (QoL), and emotional and cognitive function.MethodsIn this trial, ninety seniors with ID between the ages of 40 and 75 yrs. from occupational health centers from the Autonomous Region of Catalonia (Spain) will be recruited. Participants will be randomly allocated to the CAEP, SIT, and control group. Both intervention groups will train 3 days/week, 1.5 h/day over 6 months. Outcome variables will be assessed at baseline, 6 months and 12 months. The outcome variables include weight, height, body composition, cardiorespiratory fitness, muscle strength, balance, flexibility, cardiovascular parameters (blood pressure, pulse-wave velocity, pulse-wave analysis), QoL and cognitive function. The intervention effect will be determined with mixed models with repeated measures to assess changes in the outcome variables over time (baseline to month 12) and between study arms. Relationship between variables will be analyzed with appropriate regression analyses.DiscussionVarious studies reported on CAEP and SIT as exercise interventions for persons with ID with beneficial outcomes on body composition, fitness and blood pressure. To our knowledge, this is the first trial designed to analyse the positive changes on fitness, PA levels, cardiovascular, QoL and cognitive function promoted by CAEP training and SIT in seniors with ID. The findings of this study will assist in the development of more effective exercise interventions to ensure better compliance and adherence to exercise in seniors with ID.Trial registrationThe trial is registered at the ISRCTN registry. Registration number: ISRCTN43594228. Registered 11 February 2019 – Retrospectively registered.

Heart Rate Variability Response Following Two Physical Activity Programs In Senior With Intellectual Disability

INTRODUCTION: Improvements on heart rate variability (HRV) in healthy persons were found following exercise programs. There are gaps in our knowledge about the response of the HRV in seniors with intellectual disability (ID) without Down Syndrome (DS). PURPOSE: To compare the HRV response before, during and after 6-minutes walking test (6MWT) in seniors with ID without DS after two different exercise programs. METHODS: Fifteen seniors with mild to moderate ID without DS participated in this study. Participants were randomly divided into 3 randomized groups: sprint interval training group (SITG), combined-aerobic exercise group (AEG) and control group (CG). Participants from the SITG and AEG performed exercise 3 times/wk, 1.5 hs, during 24 wks. The 6MWT was performed before and after the programs. The intervals between R waves (RRi) were registered at rest (10 min), during the 6MWT and during the recovery (10 min) with a Polar RS800CX. HRV was analyzed by linear measures (variance) and nonlinear measure (symbolic analysis - 0V% and 2UV%). 0%V indicates sympathetic and 2UV% parasympathetic modulation. RESULTS: Distance walked on 6MWT, variance and 0%V values do not present effect of group, moment or interaction. Better values on mean (p < .001) and 2UV% (p < .01) were founded in post-intervention in comparison with pre-intervention, but neither group effect nor interactions were observed. CONCLUSION: Despite there is a tendency showing better HRV response values after physical activity programs, it cannot be concluded that exercise promotes beneficial changes on HRV responses. We believe that future studies with larger sample size are necessary to get across the changes on autonomic cardiac function and exercise in seniors with ID without DS. Funding sources: MINECO (DEP2017-86862-C2-1-R); AGAUR (2019 FI_B 00893); Ministerio de Ciência e Tecnologia de Brasil (PDSE/CAPES 88881.189815/2018-01).

A Better Approach To Improve Cardiovascular Function In Middle-aged, Inactive Human

PURPOSE: Investigate whether different aquatic aerobic exercise intensity modalities yield differential effects on vascular and endothelial function in middle-aged, inactive human METHODS: A randomized, controlled trial of middle-aged with inactive recipients 6 weeks of sprint interval training (SIT) or 6 weeks of moderate-intensity continued training (MICT). Outcomes included arterial stiffness, endothelial function, lipid metabolism, body composition and aerobic capacity. RESULTS: Twenty-six middle-aged with inactive human (mean age 41 years, 73% male) completed the study. The decrease (P<0.05) of [email protected] (augmentation index at HR of 75 beat/min) in SIT group was greater than MICT group. On the contrary, subendocardial viability ratio (SEVR) was elevated in the MICT (P<0.01) groups but not after SIT. Brachial artery BP decreased (P<0.01) by -8.1±1.5 mmHg after MICT exercise with no change in SIT. Both groups could significantly reduce fasting blood glucose (P<0.001), but only the decrease of total cholesterol was found in SIT (P<0.01). Brachial artery Flow-mediated vasodilation (FMD) was improved in both group, MICT only showed marginal significance(P=0.07)compared with SIT (P<0.05). SIT's relative VO2max and O2 pulse increased (P<0.05) by 8.4% and 8.6%, respectively, with no change in MICT. Both groups of interventions could reduce BMI (P<0.05), but SIT was mainly by increasing lean body mass (P<0.01) and decreasing fat mass (P<0.001), while the lean body mass of MICT did not change. CONCLUSIONS: The results of the present study demonstrate that short-term low-volume aquatic SIT is a time-efficient strategy to induce changes in arterial vascular stiffness, endothelial function, lipid metabolism and body composition during exercise that are comparable to changes induced by water-based traditional high-volume MICT.

Short-term Run Sit Improves Cardiovascular Health But Does Not Affect Body Composition In Undergraduate Students

The population around the world indicates that lack of time is the principal barrier to practice physical activity (PA). This perception is preponderant in undergraduate students (UE). The UE is a population characterized by show high levels of psychological stress and low PA levels; these conditions increase the risk to suffer metabolic diseases. The Sprint interval training (SIT) is a training modality that show an efficient time to modify cardiovascular variables and body composition in healthy, unhealthy population and athletes. However, the impact of SIT on UE is not completely catheterized. PURPOSE: To characterize the cardiovascular and anthropometric effects of short-term running SIT in UE. METHODS: 19 physically active males UE (age:22 ±2 yrs; weight:67±6.3 kg; height: 1.7±0.07 m) participated in this study. They were randomly assigned to control (CON) (n =9) or SIT (n =10). After baseline parameters (systolic and diastolic blood pressure -SBP and DBP-, resting heart rate (HRrest), resting double product (DP)) and body composition measurements were obtained, both groups performed a graded exercise test to determine VO2max and the running speed associated with their VO2max (sVO2peak). The exercise protocol consisted of 12 sessions (For sessions 1-3, participants ran at 100% sVO2peak with recovery periods at 40% sVO2peak, with interval ratios of 2:2 min for a total of three intervals; For sessions 4-7, the interval ratio was 2:1 min with 4 intervals and finally from the 8 to 12 session, the interval ratio was 2:1 with 5 intervals). Baseline cardiovascular, and body composition were repeated within 2 days post-intervention. RESULTS: Body composition did not change significantly by group or over time. In the SIT group, HRrest was significantly lower after training (p = 0.018). Resting SBP and DP were also decreased in the SIT group compared to CON (p <0.05). CONCLUSIONS: The data presented in the current study indicate that resting hemodynamic variables are improved by short-term run SIT in active males UE. Thus, the running SIT could be an alternative model of training with lower volume of activity for the improvement of cardiovascular health in UE. Further studies are necessary to establish the impact of the gender in response to run SIT.

The effects of personalized sprint interval training and combined aerobic endurance and resistance training on insulin resistance and glycated hemoglobin in women with type 2 diabetes

Background and aims: Exercise training is a well-established therapeutic tool for treating type 2 diabetes. The purpose of this study is to examine the beneficial effects of personalized sprint interval training (SIT) and combined aerobic endurance and resistance training (Com) on insulin resistance and glycated hemoglobin A1c (HbA1c) concentration in women with type 2 diabetes. Methods: Fifty-two overweight female type 2 diabetic patients (age 45-60 years and body mass index [BMI] &gt; 30) with HbA1c value of 6.5% or higher and fasting blood glucose (FBG) ≥ 126 mg/dL (7.0 mmol/L) were selected. Participants were recruited from patients filed in the outpatient department of Shahrekord Hospital (Shahrekord, Iran) in 2016. The participants were assigned to SIT (n=17), Com (n=17), and control groups (n=18) according to HbA1c levels. The exercises included 10 weeks of Com and SIT. Results: HbA1c concentrations decreased significantly in SIT (P=0.002) and Com (P=0.006) groups. The dependent t-test revealed that differences were significant for the FBG in the SIT groups (P&lt;0.001). Serum insulin levels showed significant increases in the SIT (P&lt;0.001) and Com (P&lt;0.001) groups. Data showed significant differences in homeostasis model assessment-estimated insulin resistance (HOMA-IR) in SIT (P&lt;0.001) and Com (P&lt;0.001) groups. The analysis of covariance (ANCOVA) test showed significant differences in serum insulin (F=3.622, P=0.02) and HOMA-IR (F=5.511, P=0.0001) levels and no significant difference in HbA1c (F=0.597, P=0.556) and FBG concentrations (F=1.853, P=0.171). Conclusion: Results highlight that individualized exercise training, independent of the mode of training, is effective in improving glycemic control in overweight patients with type 2 diabetes.

The Effects of In-Season, Low-Volume Sprint Interval Training With and Without Sport-Specific Actions on the Physical Characteristics of Elite Academy Rugby League Players

To determine the utility of running-only and rugby-specific, in-season sprint interval interventions in professional rugby league players. Thirty-one professional academy rugby players were assigned to a rugby-specific (SITr/s, n = 16) or running-only (SITr, n = 15) sprint interval training group. Measures of speed, power, change of direction ability, prone Yo-Yo Intermittent Recovery Test (Yo-Yo IR1) performance, and heart rate recovery were taken before and after the 2-week intervention as were submaximal responses to the prone Yo-Yo IR1. Internal, external, and perceptual responses were collected during SITr/s and SITr, with well-being and neuromuscular function assessed before each session. Despite contrasting (possible to most likely) internal, external, and perceptual responses to the SIT interventions, possible to most likely within-group improvements in physical characteristics, heart rate recovery, and submaximal responses to the prone Yo-Yo IR1 were observed after both interventions. Between-group analysis favored the SITr/s intervention (trivial to moderate) for changes in 10-m sprint time, countermovement jump, change of direction, and medicine ball throw as well as submaximal (280-440m) high metabolic power, PlayerLoad™, and acceleration distance during the prone Yo-Yo IR1. Overall changes in well-being or neuromuscular function were unclear. Two weeks of SITr/s and SITr were effective for improving physical characteristics, heart rate recovery, and submaximal responses to the prone Yo-Yo IR1, with no clear change in well-being and neuromuscular function. Between-group analysis favored the SITr/s group, suggesting that the inclusion of sport-specific actions should be considered for in-season conditioning of rugby league players.

Effect of High-Intensity Interval Training Versus Sprint Interval Training on Time-Trial Performance: A Systematic Review and Meta-analysis.

Two forms of interval training commonly discussed in the literature are high-intensity interval training (HIIT) and sprint interval training (SIT). HIIT consists of repeated bouts of exercise that occur at a power output or velocity between the second ventilatory threshold and maximal oxygen consumption (VO2max). SIT is performed at a power output or velocity above those associated with VO2max. The primary objective of this study is to systematically review published randomized and pair-matched trials to determine which mode of interval training, HIIT versus SIT, leads to a greater improvement in TT performance in active and trained individuals. The second objective of this review is to perform a subgroup analysis to determine if there is a distinction between HIIT programs that differ in work-bout duration. SPORTDiscus (1800-present) and Medline with Full Text (1946-present) were used to conduct a systematic literature search. Studies were selected for the review if they met the following criteria: (1) individuals (males and females) who were considered at least moderately trained (~ 3-h per week of activity) as specified by the authors of the included studies; (2) between the ages of 18 and 45years; (3) randomized or pair-matched trials that included a HIIT and a SIT group; (4) provided detailed information about the interval training program; (5) were at least 2weeks in duration; (6) included a TT test that required participants to complete a set distance. A total of 6 articles met the inclusion criteria for the subjective and objective analysis. The pooled analysis was based on a random-effects model. There was no difference in the change in TT performance when comparing all HIIT versus SIT (0.9%; 90% CI -1.2-1.9%, p = 0.18). However, subgroup analysis based on duration of work interval indicated a 2% greater improvement in TT performance following long-HIIT (≥4min) when compared to SIT. There was no difference in change in VO2max/peak oxygen consumption (VO2peak) between groups. There was a moderate effect (ES = 0.70) in favor of HIIT over SIT in maximal aerobic power (MAP) or maximal aerobic velocity (MAV). The results of the meta-analysis indicate that long-HIIT may be the optimal form of interval training to augment TT performance. Additional research that directly compares HIIT exercise differing in work-bout duration would strengthen these results and provide further insight into the mechanisms behind the observed benefits of long-HIIT.