EFFECT OF DIFFERENT INTERVAL SPEED TRAINING ON ATHLETE REACTION

ABSTRACT Introduction: High-intensity Intermittent Training (HIIT) ranked first in the ACSM “2013 Global Training Methodology Survey”. Objective: To explore the influence of different speed training intervals on athlete reaction speed. Methods: Sixteen male bicycle athletes were randomly divided into two groups. The two groups then completed a six-week training routine (NT). The two groups then completed a six-week training routine , started 6 weeks of Sprint Interval Training (SIT) (a total of 12 lessons), with SIT instead of Normal Training (NT) live endurance training, and another training remains unchanged. Results: After 6 weeks of NT, Pmax GXT in the CG and DG groups decreased by 0.7% and 1.7%, respectively,as compared to the pre-training numbers. The difference was not statistically significant (P>0.05). And after 6 weeks of SIT, Pmax GXT increased significantly (P<0.05) in both experimental groupss,with increases of 9.2% and 10.2% for the CG and DG groups, respectively. Conclusions: The results show that intermittent training can effectively improve the aerobic metabolism of short-haul cyclists. As the power bicycle load and the training intensity and volume of the deceleration intermittent training program increase, the more significant the changes in aerobic capacity that can result in adaptability. Level of evidence II; Therapeutic studies - investigation of treatment results.

The Influence of Acute Sprint Interval Training on Cognitive Performance of Healthy Younger Adults

There is considerable evidence showing that an acute bout of physical exercises can improve cognitive performance, but the optimal exercise characteristics (e.g., exercise type and exercise intensity) remain elusive. In this regard, there is a gap in the literature to which extent sprint interval training (SIT) can enhance cognitive performance. Thus, this study aimed to investigate the effect of a time-efficient SIT, termed as “shortened-sprint reduced-exertion high-intensity interval training” (SSREHIT), on cognitive performance. Nineteen healthy adults aged 20–28 years were enrolled and assessed for attentional performance (via the d2 test), working memory performance (via Digit Span Forward/Backward), and peripheral blood lactate concentration immediately before and 10 minutes after an SSREHIT and a cognitive engagement control condition (i.e., reading). We observed that SSREHIT can enhance specific aspects of attentional performance, as it improved the percent error rate (F%) in the d-2 test (t (18) = −2.249, p = 0.037, d = −0.516), which constitutes a qualitative measure of precision and thoroughness. However, SSREHIT did not change other measures of attentional or working memory performance. In addition, we observed that the exercise-induced increase in the peripheral blood lactate levels correlated with changes in attentional performance, i.e., the total number of responses (GZ) (rm = 0.70, p < 0.001), objective measures of concentration (SKL) (rm = 0.73, p < 0.001), and F% (rm = −0.54, p = 0.015). The present study provides initial evidence that a single bout of SSREHIT can improve specific aspects of attentional performance and conforming evidence for a positive link between cognitive improvements and changes in peripheral blood lactate levels.

Divergent serum metabolomic, skeletal muscle signalling, transcriptomic and performance adaptations to fasted versus whey protein-fed sprint interval training

Sprint interval training (SIT) is a time efficient alternative to endurance exercise, conferring beneficial skeletal muscle metabolic adaptations. Current literature has investigated the nutritional regulation of acute and chronic exercise-induced metabolic adaptations in muscle following endurance exercise, principally comparing the impact of training in fasted and carbohydrate-fed (CHO) conditions. Alternative strategies such as exercising in low CHO, protein-fed conditions remain poorly characterised, specifically pertaining to adaptations associated with SIT. Thus, this study aimed to compare the metabolic and performance adaptations to acute and short term SIT in the fasted state with pre-exercise hydrolysed (WPH) or concentrate (WPC) whey protein supplementation. In healthy males, pre-exercise protein ingestion did not alter exercise-induced increases in PGC-1α, PDK4, SIRT1, and PPAR-δ mRNA expression following acute SIT. However, supplementation of WPC and WPH beneficially altered acute exercise-induced SIRT4 and CD36 mRNA expression, respectively. Pre-exercise protein ingestion attenuated acute exercise-induced increases in muscle pan-acetylation, and PARP1 protein content compared with fasted SIT. Acute serum metabolomic differences confirmed greater pre-exercise amino acid delivery in protein-fed compared with fasted conditions. Following 3 weeks of SIT, training-induced increases in mitochondrial enzymatic activity and exercise performance were similar across nutritional groups. Interestingly, resting muscle acetylation status was favourably regulated in WPH conditions following training. Such findings suggest pre-exercise WPC and WPH ingestion positively influences metabolic adaptations to SIT compared to fasted training, resulting in either similar or enhanced performance adaptations. Future studies investigating nutritional modulation of metabolic adaptations to exercise are warranted to build upon these novel findings.

Vitamin C and E Treatment Blocks Changes in Kynurenine Metabolism Triggered by Three Weeks of Sprint Interval Training in Recreationally Active Elderly Humans

The kynurenine pathway (KP) is gaining attention in several clinical fields. Recent studies show that physical exercise offers a therapeutic way to improve ratios of neurotoxic to neuroprotective KP metabolites. Antioxidant supplementation can blunt beneficial responses to physical exercise. We here studied the effects of endurance training in the form of sprint interval training (SIT; three sessions of 4–6 × 30 s cycling sprints per week for three weeks) in elderly (~65 years) men exposed to either placebo (n = 9) or the antioxidants vitamin C (1 g/day) and E (235 mg/day) (n = 11). Blood samples and muscle biopsies were taken under resting conditions in association with the first (untrained state) and last (trained state) SIT sessions. In the placebo group, the blood plasma level of the neurotoxic quinolinic acid was lower (~30%) and the neuroprotective kynurenic acid to quinolinic acid ratio was higher (~50%) in the trained than in the untrained state. Moreover, muscle biopsies showed a training-induced increase in kynurenine aminotransferase (KAT) III in the placebo group. All these training effects were absent in the vitamin-treated group. In conclusion, KP metabolism was shifted towards neuroprotection after three weeks of SIT in elderly men and this shift was blocked by antioxidant treatment.

Sprint Interval Training: Recovery Format, Enjoyment and Blood Pressure in Inactive Men

ABSTRACT Background: While the efficacy of sprint interval training (SIT) to provide positive health effects in inactive populations is established, feasibility is associated with enjoyment and safety, which are dependent on the acute physiological and perceptual responses. The recovery format likely influences physiological and perceptual responses that occur during and immediately after SIT. It was hypothesized that during SIT interspersed with active recovery periods, enjoyment and blood pressure (BP) values would be higher compared with passive recovery periods, in inactive participants. Methods: Twelve males (mean ± SD; age 23 ± 3 y) completed 3 exercise sessions on a cycle ergometer in a randomized order on separate days: (a) SIT with passive recovery periods between 4 bouts (SITPASS), (b) SIT with active recovery periods between 4 bouts (SITACT), and (c) SITACT with the 4 SIT bouts replaced with passive periods. BP was measured immediately after each bout and every 2 min during a 6 min recovery. Physical activity enjoyment was measured during postexercise recovery. Results: There were no significant differences in physical activity enjoyment or systolic BP between SITPASS and SITACT. Diastolic BP was lower during recovery in SITACT (P = 0.025) and SITPASS (P = 0.027), compared with resting BP. Furthermore, diastolic BP was lower after 6 min of recovery following SITPASS, compared with SITACT (P = 0.01). Conclusion: Exercise enjoyment and acute systolic BP responses were independent of SIT recovery format in inactive men. Reductions in diastolic BP were greater and more prolonged after SIT protocols that included passive recovery periods.