The aim of this study was to investigate the effects of acute high-intensity interval training (HIIT) on immune function and oxidative stress in male canoe/kayak athletes who were well trained. A total of 22 participants were voluntarily recruited with an age range of 15.9 ± 2.3 years, height of 172.2 ± 5.5 cm, body mass of 63.30 ± 6.95 kg, and body fat of 13.77 ± 3.76%. The modified Wingate kayaking test on a kayak ergometer was performed by all participants. Blood samples were collected at three different time points: before the test (Pre-T), immediately after (Post-T), and 3 h post-test (Post-3 h). Saliva samples were collected at two different time points: before the test (Pre-T) and 3 h after the test (Post-3 h). Results indicated that acute canoe/kayak ergometry HIIT had significant effects on the percentages and counts of leukocytes, neutrophils, lymphocytes, and lymphocyte subsets. Additionally, it resulted in increased total LPS-stimulated neutrophil elastase release and alterations in plasma concentrations of superoxide dismutase, catalase, and TBARS. These findings suggest that conventional kayak HIIT regimens can have short-term effects on immune function and induce oxidative stress in athletes.

This study sought to compare the biomechanical parameters of the lower extremities during a countermovement jump in elderly people who are engaged in frequent practice of tai chi chuan (TCG) and in the general population of healthy elderly people (HG). Each group included 12 participants. Ten Vicon Motion System infrared cameras and two Kistler force plates were employed for measurement. The jump height, duration, centre of mass (COM) displacement, joint ROM, and upward velocity were analysed in this study. Motion analysis and force platform data were combined to calculate joint moments and powers during the takeoff phase. The data were analysed using independent sample t-tests. The results showed that the tai chi chuan practitioner group (0.13 m) achieved 44% higher jump heights (p < 0.05). The COM displacement during squatting was lower in the TCG (0.25 m) than in the HG (0.19 m) (p < 0.05). The knee and ankle ROMs of the TCG were higher than those of the HG (p < 0.05). Peak knee moment 23% and peak knee power 32% higher in TCG compared to the HG (p < 0.05), suggesting that frequent practice of tai chi chuan may slow the rate of knee degeneration.

Background: It is known that lower-limb muscle strength is easily maintained in elderly people who practice Tai Chi, although it is necessary to maintain lower-limb muscle strength even as age increases in order to prevent falls. However, the effect of long-term Tai Chi practice and age on lower-limb ability is unclear in middle-aged and elderly people. This research was designed to compare lower-extremity parameters during a countermovement jump between middle-aged and elderly individuals who frequently practice Tai Chi Chuan and individuals in the general population who constituted the healthy group. Methods: There were four groups, and each group included 12 participants. Ten Vicon motion system infrared cameras and two Kistler force plates were used. The data were standardized and analysed using independent-measure two-way ANOVA. Results: The statistical results showed that there was no interaction between the age factor and exercise type factor. The statistics of age factor also showed that age may decrease the jump height (36.36%), peak knee power (24.74%) and peak ankle power (21%) during the take-off phase. In the exercise type factor, long-term Tai Chi training significantly increased the jump height (60%), peak knee moment (19.80%), peak ankle moment (8.06%), peak hip power (29.80%), peak knee power (31.23%) and peak ankle power (16.88%) during the take-off phase. Conclusion: This study shows that long-term Tai Chi training can slow ageing-related functional decline. According to the results of this study, middle-aged and elderly people are encouraged to regularly perform Tai Chi exercises to increase the strength of various muscle groups in the lower limbs and slow the lower-limb muscle changes caused by ageing.

Background/Objectives: While previous evidence has shown that using free weights for resistance training is a more practical approach to enhancing strength, there is a relatively low prevalence of free-weight resistance training among adolescent kayak/canoe athletes. Therefore, this study aims to assess the impact of free-weight resistance training on body composition and various performance factors among adolescent canoe/kayak athletes. Methods: Twenty-seven young sprint kayakers and canoeists (14 ± 1 years; 164 ± 7 cm; 56 ± 8 kg) completed this study. Following baseline assessments, athletes were randomly divided into two training groups: the free-weight resistance training group (FW) or the control group (C). The FW group underwent free-weight resistance training sessions twice weekly for 24 weeks. The C group maintained their regular bodyweight training sessions during the same timeframe. All participants performed both the pre- and post-training assessments for the following dependent variables: body composition, upper-body power, upper-body isometric muscle strength, isometric mid-thigh pull, core strength, countermovement jump, balance, anaerobic ability, and aerobic performance. Results: After 24 weeks of training, the free-weight resistance training group exhibited a significant increase in body weight (from 56 ± 5 kg to 58 ± 4 kg, p < 0.05) and improvements in the number of straight leg raise repetitions (from 23 ± 6 to 26 ± 4, p < 0.05) compared to the control group. However, the two groups observed no significant differences between upper-body isometric muscle strength, power, balance, and anaerobic/aerobic performance. Conclusions: A 24-week training duration might be insufficient for novice participants in resistance training. Future research should consider incorporating an adaptation period or a learning phase for movements before training, thereby enhancing the efficacy of free-weight resistance training in increasing strength.

This study aimed to investigate the effects of three sprint start techniques: block, three-point, and standing starts on 50-meter sprint performance and neuromuscular control. Sixteen collegiate male sprinters, all of whom were Division I athletes from the National Taiwan University of Sport's track and field program, were recruited to complete three randomized trials for each of the three start conditions. Electromyography, joint kinematics, and spatiotemporal gait analyses were used to assess reaction time, movement time, segmental velocity, lower-limb muscle activation, joint motion, and step patterns across steps 1 to 9 during the initial sprint phase. A one-way repeated-measures ANOVA ( α = .05) was applied for statistical analysis. The results demonstrated that the block start yielded the shortest movement time ( p < .001) and the highest velocity ( p < . 01). The three-point start outperformed the standing start in terms of 50 m average sprint velocity ( p < .001), peak gastrocnemius activation at the ankle ( p < . 01), and rectus femoris activation at the knee ( p < .001). These advantages were accompanied by greater pre-activation of key muscle groups and enhanced ankle and knee joint stability from the set position through the initial sprint phase. These findings suggest that the three-point start may serve as a practical alternative in scenarios where starting blocks are unavailable and could be implemented in youth training programs or cross-sport performance testing contexts.