Six Weeks of Hip Joint Training Using a Novel Multihip Joint Board Improves Sprint Performance in Competitive Collegiate Male Sprinters.

ABSTRACT: Nakata, H, Nakanishi, Y, Otsuki, S, Mizuno, M, Connor, J, and Doma, K. Six weeks of hip joint training using a novel multihip joint board improves sprint performance in competitive collegiate male sprinters. J Strength Cond Res 36(10): 2891-2897, 2022-In a previous study, we identified the possibility that hip joint training using a multihip joint board (MHJB) may increase the cross-sectional area (CSA) of the psoas major (PM) muscle and improve sprint performance. However, the preliminary study reported descriptive findings because of a limited sample size. Therefore, we aimed to investigate and statistically infer the effects of the MHJB training protocol with a larger sample of male collegiate sprinters. The sprinters were randomly assigned to either the MHJB group ( n = 7) or the control group ( n = 7). The MHJB protocol consisted of 7 separate exercises targeting the development of the hip musculature, all using the MHJB device. The MHJB group undertook the MHJB protocol 3 times per week for 6 weeks, after their normal daily workout, whereas the control group completed their normal daily workout without the MHJB protocol. Sprint performance was recorded from official 100-m competitions before, and after, the 6-week training period. At the end of the training period, significantly greater improvement in PM CSA and 100-m sprint was noted in the MHJB group compared with the control group. These findings confirm the efficacy of MHJB training for increasing PM CSA and improve sprint performance in competitive male sprinters.

High-intensity interval training improves respiratory and cardiovascular adjustments before and after initiation of exercise.

Purpose: High-intensity interval training (HIIT) may induce training-specific physiological adaptations such as improved respiratory and cardiovascular adjustments before and after the onset of high-intensity exercise, leading to improved exercise performance during high-intensity exercise. The present study investigated the effects of HIIT on time-dependent cardiorespiratory adjustment during maximal exercise and before and after initiation of high-intensity exercise, as well as on maximal exercise performance. Methods: 21 healthy male college students were randomly assigned to HIIT group (n = 11) or control group (n = 10). HIIT group performed training on a cycle ergometer once a week for 8 weeks. The training consisted of three bouts of exercise at 95% maximal work rate (WRmax) until exhaustion. Before and after the HIIT program, dynamic cardiorespiratory function was investigated by ramp and step exercise tests, and HIIT-induced cardiac morphological changes were assessed using echocardiography. Results: HIIT significantly improved not only maximal oxygen uptake and minute ventilation, but also maximal heart rate (HR), systolic blood pressure (SBP), and time to exhaustion in both exercise tests (p < 0.05). Time-dependent increases in minute ventilation (VE) and HR before and at the start of exercise were significantly enhanced after HIIT. During high-intensity exercise, there was a strong correlation between percent change (from before to after HIIT program) in time to exhaustion and percent change in HRmax (r = 0.932, p < 0.001). Furthermore, HIIT-induced cardiac morphological changes such as ventricular wall hypertrophy was observed (p < 0.001). Conclusion: We have demonstrated that HIIT at 95% WRmax induces training-specific adaptations such as improved cardiorespiratory adjustments, not only during maximal exercise but also before and after the onset of high-intensity exercise, improvement of exercise performance mainly associated with circulatory systems.