The Effects of Incorporating Dry-land Short Intervals to Long Aerobic-dominant In-Water Swimming Training on Physiological Parameters, Hormonal Factors, and Performance: A Randomized-Controlled Intervention Study

A Comparative Analysis of High-Intensity Technique-Specific Intervals and Short Sprint Interval Training in Taekwondo Athletes: Effects on Cardiorespiratory Fitness and Anaerobic Power

Technique-specific high-intensity interval training (HIITTS) has been proven to be an effective method to enhance the sport-specific bio-motor abilities of taekwondo athletes. However, studies regarding its effects on comprehensive measures of cardiorespiratory fitness are limited. Furthermore, there is a lack of clarity regarding the extent of individual adaptations to this method compared to HIIT in the form of repeated sprints (HIITRS). This study compared the individual adaptations to HIITRS and HIITTS on cardiorespiratory fitness and anaerobic power in trained taekwondo athletes (age = 19.8 ± 1.3 years; body mass = 75.4 ± 9.1 kg; height = 1.73 ± 0.0 .m). All participants completed three sessions per week of a 60-minute regular taekwondo training. Following the 60-minute training, participants completed 3 sets of 10 × 4 s all-out HIITRS or same sets of repeated kicks with both legs (HIITTS) over a 6-week training period. In both groups, rest intervals were set at 15 seconds between efforts and one minute between sets. Before and after the training period, participants underwent a series of lab- and field-based tests to evaluate cardiorespiratory fitness and bio-motor abilities. Both interventions resulted in significant improvements in maximum oxygen uptake (V̇O2max), O2 pulse (V̇O2/HR), first ventilatory threshold (VT1), second ventilatory threshold (VT2), cardiac output (Q̇max), stroke volume (SV), peak power output (PPO), average power output (APO), squat jump (SJ), and countermovement jump (CMJ). However, linear speed (20-m speed time) and taekwondo-specific agility test (TSAT) only responded to HIITRS. HIITRS resulted in greater changes in V̇O2max, V̇O2/HR, VT2, and Q̇max, and higher percentage of responders in measured parameters than HIITTS. In addition, HIITRS elicited lower inter-individual variability (CV) in percent changes from pre- to post-training in all measured variables. These results suggest that incorporating 3 sessions per week of HIITRS into regular taekwondo training results in significantly greater and more homogenized adaptations in cardiorespiratory fitness and bio-motor abilities than HIITTS among trained taekwondo athletes.

Adaptations to Optimized Interval Training in Soccer Players: A Comparative Analysis of Standardized Methods for Individualizing Interval Interventions

Accurately prescribing supramaximal interval training facilitates targeting desired physiological adaptations. This study compared the homogeneity of adaptations in cardiorespiratory parameters to supramaximal [i.e., intensities beyond maximal aerobic speed (MAS)] interval interventions prescribed using anaerobic speed reserve (ASR), the speed attained at the end of 30-15 Intermittent Fitness Test (VIFT), and MAS. Using repeated-measures factorial design, and during the off-season phase of the athletes' yearly training cycle, thirty national-level soccer players (age = 19 ± 1.6 years; body mass = 78.9 ± 1.6 kg; height = 179 ± 4.7 cm; Body fat = 11 ± 0.9%) were randomized to interventions consisting of 2 sets of 6, 7, 8, 7, 8, and 9-min intervals (from 1st to 6th week), including 15 s running at Δ%20ASR (MAS + 0.2 × ASR), 120%MAS, or 95%VIFT followed by 15 s passive recovery. All ASR, VIFT, and MAS programs sufficiently stimulated adaptive mechanisms, improving relative maximal oxygen uptake [V̇O2max (p < 0.05; ES = 1.6, 1.2, and 1.1, respectively)], absolute V̇O2max (p < 0.05; ES = 1.5, 1.1, and 0.7), ventilation [V̇E (p < 0.05; ES = 1.6, 1.1, and 1.1)], O2 pulse [V̇O2/HR (p < 0.05; ES = 1.4, 1.1, and 0.6)], first and second ventilatory threshold [VT1 (p < 0.05; ES = 0.7, 0.8, and 0.7) and VT2 (p < 0.05; ES = 1.1, 1.1, and 0.8)], cardiac output [Q̇max (p = 1.5, 1.0, and 0.7)], and stroke volume [SVmax (p < 0.05; ES = 0.9, 0.7, and 0.5)]. Although there was no between-group difference for the change in the abovementioned variables over time, supramaximal interval training prescribed using ASR and VIFT resulted in a lower coefficient of variation [CV (inter-individual variability)] in physiological adaptations compared to exercise intensity determined as a proportion of MAS. Expressing the intensity of supramaximal interval programs according to the athlete's ASR and VIFT would assist in accurately prescribing interventions and facilitate imposing mechanical and related physiological stimulus according to the athletes' physiological ceiling. Such an approach leads to identical stimulation across athletes with differing profiles and potentially facilitates more homogenized adaptations.