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.

Effects of social network incentives and financial incentives on physical activity and social capital among older women: a randomized controlled trial.

BACKGROUND: Financial incentives have been used to increase physical activity. However, the benefit of financial incentives is lost when an intervention ends. Thus, for this study, we combined social network incentives that leverage the power of peer pressure with financial incentives. Few reports have examined the impact of physical activity on social capital. Therefore, the main goal of this study was to ascertain whether a combination of two incentives could lead to more significant changes in physical activity and social capital during and after an intervention. METHODS: The participants were 39 older women over 65 years of age in Kumamoto, Japan. The participants were randomly divided into a financial incentive group (FI group) and a social network incentive plus financial incentive group (SNI + FI group). Both groups underwent a three-month intervention. Measurements of physical activity and social capital were performed before and after the intervention. Additionally, the effects of the incentives on physical activity and social capital maintenance were measured 6 months postintervention. The financial incentive group received a payment ranging from US$4.40 to US$6.20 per month, depending on the number of steps taken during the intervention. For the other group, we provided a social network incentive in addition to the financial incentive. The SNI + FI group walked in groups of three people to use the power of peer pressure. RESULTS: A two-way ANOVA revealed that in terms of physical activity, there was a statistically significant interaction between group and time (p = 0.017). The FI group showed no statistically significant improvement in physical activity during the observation period. In terms of the value of social capital, there was no significant interaction between group and time. CONCLUSION: Our results suggest that social network incentives, in combination with financial incentives, are more effective for promoting physical activity than financial incentives alone among older women and that these effects can continue after an intervention. In the meantime, further studies should be conducted on the effect of physical activity on social capital. TRIAL REGISTRATION: UMIN000038080 , registered on 09/22/2019 (Retrospectively registered).

A vertical load applied towards the trunk unilaterally increases the bilateral abdominal muscle activities.

[Purpose] It is considered that evaluation of the vertical trunk function is important, because humans stand and move with two legs. To evaluate this, a novel method named Trunk Righting Test has been reported. The purpose of this study was to examine the trunk muscle activity during a TRT using electromyogram analysis. [Participants and Methods] This study included 7 healthy volunteer males. The TRT evaluated the supportability of the posture after moving 10 cm laterally from the sitting position using a hand-held dynamometer. The TRT measurements were analyzed separately at the measurement side (ipsilateral side) and at the non-measurement side (contralateral side). The measurements were obtained bilaterally, and the evaluated muscles included the rectus abdominis, internal oblique, external oblique, multifidus, and transversus abdominis. The measured value was expressed as a percentage after comparing with the value at the maximum voluntary contraction (% MVC) for standardization. The changes in the muscle activities in the sitting position and TRT were evaluated. [Results] All the muscle activities significantly increased during the TRT in contrast to that in the sitting posture. [Conclusion] The load support of the trunk on one side during the TRT was significant in all the muscles on both the sides, which increased the muscle activity, in contrast to that in the sitting position.

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.

The effects of vertical trunk supportability improvement on one-leg rebound jump efficiency.

The purpose of this study was to examine the effects of vertical trunk supportability improvement on activities. The study participants were 36 people. Trunk function and physical performance were evaluated using the following tests: trunk righting test (TRT), maximal isometric knee extensor strength test, side hop test, triple hop distance test, stabilometry of one-leg standing, and one-leg rebound jump. The measurement was performed three times: pre-trunk training (pre), post-trunk training for 1 month (post), and 2 months after the second measurement (detraining). Details of trunk training: Two sets of 30-s maximal lateral reach exercises on each side, following the four sets of 15-s maximal raising trunk exercises on each side. The results with TRT in post-training were significantly larger than those in pre-and detraining. Similarly, the results with one-leg rebound jump efficiency in post-training were significantly larger than those in pre-and detraining. Our findings indicate that jump efficiency changes in proportion to the change in vertical trunk supportability.

The effects of toe grip training on physical performance and cognitive function of nursing home residents.

BACKGROUND: Toe grip-related training requires individuals to actively exercise muscles that are not frequently used; therefore, it may improve not only toe grip strength but also cognitive function. The purpose of this study was to examine the effects of toe grip-related training on predictors of physical performance and cognitive function in nursing home residents. METHODS: A total of 35 nursing home residents (35 left and 35 right feet; mean age, 82.1 ± 7.9 years) were included in this study. The participants were divided into two groups: a training group and a control group. The Mini-Mental State Examination (MMSE) was used to assess the cognitive function of the participants, and the Fall Risk Index (FRI) was used to evaluate the risk of falls. Toe grip-related physical function was also assessed. Baseline endpoints were evaluated and the effects of toe grip-related training were examined following a 12-week training intervention. RESULTS: The training group showed significant improvements in MMSE score, FRI score, toe grip strength, and the toe skill (TS) test; however, the control group did not show these changes. The training group showed significant increases in Δ MMSE, Δ toe grip strength, and Δ TS (right foot) than the control group. Stepwise regression analysis revealed that Δ toe grip strength is an independent factor of Δ MMSE. CONCLUSIONS: Toe grip training improves not only toe grip strength itself, but also cognitive function. Furthermore, change in toe grip strength was an independent factor of change in MMSE in those populations. TRIAL REGISTRATION: UMIN, UMIN000027437 . Registered on 26 May 2017.

Toe grip strength in middle-aged individuals as a risk factor for falls.

BACKGROUND: Toe grip strength is the force of a toe on a surface. The objective of this study was to investigate the relationship between falls in middle-aged individuals and physical strength factors such as toe grip strength and knee extension strength. METHODS: The subjects were 194 middle-aged individuals (388 feet) who were independent in daily life, received no nursing care, and participated in a health sports event organized by a sports club. We evaluated the body composition, blood pressure, vascular age, systemic response, bone density, knee extension strength, and toe grip strength, and examined their relationship using a self-administered questionnaire survey. RESULTS: The fall, near-fall, and no fall groups included 7, 36, and 151 subjects, respectively; the high and low risk groups included 43 and 151 subjects, respectively. Logistic regression analysis was performed with risk of falls as the dependent variable, and factors that showed a significant difference in the comparison of the high and low risk groups as independent variables. In this analysis, toe grip strength and diastolic blood pressure were identified as independent risk factors for a fall. CONCLUSIONS: Toe grip strength is an independent risk factor for falls, and improvement of toe grip strength might prevent falls.

Smoking counteracts the favorable effect of exercise training on endothelial function in patients with type 2 diabetes.

BACKGROUND: Exercise training can improve endothelial function in patients with diabetes. We hypothesized that the favorable effect of exercise training on endothelial function in patients with diabetes is counteracted by cigarette smoking. PURPOSE: To assess whether there is a difference in the effect of exercise on endothelial function in smokers and non-smokers with type 2 diabetes. METHODS: We performed a 3-month controlled trial in 27 never-smoking and 17 smoking individuals with type 2 diabetes who participated in a home-based walking program. The percentage decrease in post-exercise ankle-brachial pressure index (ABI), which is an index of endothelial function, was assessed at baseline and after 3 months. RESULTS: Compared to the smoking group, the never-smoking group showed a more significant improvement in post exercise ABI during the 3 months of home-based training (interaction, P < 0.01). CONCLUSIONS: These results indicate that smoking may counteract the favorable effects of exercise training on endothelial function. Endothelial function plays an important role in the prevention of cardiovascular disease among patients with diabetes. Therefore, a Certified Diabetes Educator should strongly advise diabetic patients not to smoke.

Post-exercise ankle-brachial pressure index demonstrates altered endothelial function in the elderly.

BACKGROUND: The ankle-brachial pressure index (ABI), the ratio of the systolic blood pressure of the ankle to the systolic brachial pressure, is commonly measured at rest, but ABI values post-exercise enhance the sensitivity of the test and can be used to identify atherosclerotic vascular damage. However, it has not been established whether or not enhanced post-exercise ABI is also associated with endothelial dysfunction. We hypothesized that a decrease in post-exercise ABI is related to impaired endothelial function. PURPOSE: To investigate alterations in post-exercise ABI values and endothelial dysfunction in the elderly. METHODS: The study population comprised 35 men and women aged 51-77 years (mean age: 66 years). Patients with peripheral arterial disease or a history of heart failure were excluded. The ABI was estimated at rest and immediately after exercise. The exercise protocol comprised 2.5 min of active pedal flexion exercises at a speed of 60 times/min. Endothelial function was assessed by measuring flow-mediated vasodilation (FMD) in the brachial artery using ultrasound imaging. RESULTS: No correlation was found between FMD and the ABI at rest. However, a weak correlation was found between FMD and post-exercise ABI (r = 0.46, P = 0.06). A strong correlation was observed between FMD and a decrease in post-exercise ABI compared to baseline readings (r = -0.52, P = 0.01). Multiple linear regression analysis was used to generate a prediction equation for FMD using the percentage decrease in post-exercise ABI. Significant correlations were observed between the ultrasound imaging-measured FMD and the predicted FMD (R(2) = 0.27, P = 0.001). CONCLUSIONS: Post-exercise ABI appears to be a simple surrogate marker for endothelial function in the elderly, although larger studies are required for validation.