International journal of sports medicine最新文献

Iron and vitamin D deficiencies can affect athletes' health and performance. However, the epidemiology and associated risk factors remain unclear. Forty-three elite female athletics athletes (20.2 ± 1.9 years) were included. A survey regarding the training schedule and Eating Attitudes Test-26, body composition, bone mineral density, and serum 25-hydroxyvitamin D (25(OH)D) and ferritin levels were assessed. Mean serum 25(OH)D and ferritin levels were 25.2 ± 5.5 ng/mL and 29.0 ± 13.2 ng/mL, respectively, and 83.7% and 41.9 % of athletes had vitamin D and ferritin insufficiency, respectively. Serum 25(OH)D level was negatively correlated with the number of rest days per week (Coefficient, -6.19; 95% confidence interval [CI], -9.82--2.57; p = 0.002), and serum ferritin level was negatively correlated with body mass index (Coefficient, -3.87; 95% CI, -7.57--0.16; p = 0.041). Performance levels were positively correlated with serum vitamin D levels (Coefficients, 7.25; 95% CI, 0.25-14.25; p = 0.043) and negatively correlated with EAT-26 scores (Coefficient, -7.30; 95% CI, -12.61--1.98; p = 0.009) and body fat percentage (Coefficient, -13.26; 95% CI, -24.66--1.86; p = 0.025). Vitamin D and ferritin insufficiencies are prevalent among Japanese female athletics athletes. Serum vitamin D level was related to performance level.

Running performance is crucial for triathlon performance. However, the prior bout of cycling may affect the running split time. This study compared the triathletes' cycling plus running (C+R) time, when cycling was performed at three different intensities and running was maximal. A total of 38 athletes (21 males and 17 females) were included. Body composition, maximal oxygen uptake, and functional threshold power (FTP) was evaluated. The participants visited the laboratory three times to cycle 20 km at 80%, 85%, or 90% FTP (in randomized order) and run 5 km as fast as possible. Males ran faster after cycling at 80% FTP than after cycling at 90% FTP (mean difference=35.1 s; CI% 2.2, 68.1 s; p=0.035). The C+R time was faster when cycling at 90% FTP than at 80% FTP (mean difference=57.7 s; CI% 26.1, 89.3 s; p<0.001). For females, no significant difference was observed in the running time after cycling at 80%, 85%, or 90% FTP. The C+R time was faster when cycling at 90% FTP than at 80% FTP (mean difference=80.9 s; CI% 29.7, 132.1 s; p=0.002). In conclusion, to optimize triathlon performance, male and female athletes should cycle at a minimum of 90% FTP.

This study assessed the repeated sprint performance in relation to circadian rhythm during different menstrual cycle phases (MCP). Twelve volunteer eumenorrheic women team sport athletes performed 5×6-s cycling sprints in morning (9 am to 10 am) and evening (6 pm to 7 pm) sessions during the mid-follicular (FP, 6^th-10^th d) and luteal phases (LP, 19^th-24^th d). Body weight, oral body temperature, resting heart rate and lactate levels together with estradiol, progesterone and cortisol levels were determined before tests. Relative peak and mean power and performance decrements were determined as performance variables and maximum heart rate, lactate and ratings of perceived exertion were determined as physiological variables. Evening body temperatures were significantly higher. Cortisol levels were higher in the morning and in the FP. Resting lactate levels did not vary with MCP or time of day, but a significant MCP x time of day interaction was observed. Body weight showed no change according to time of day and MCP. There was no significant effect of MCP and time of day on performance and physiological variables, in contrast, maximum lactate values were notably higher in the evening. In conclusion, MCP and time of day need not be considered during repeated sprint exercises of eumenorrheic women athletes.

The proliferation of wearable devices, especially over the past decade, has been remarkable. Wearable technology is used not only by competitive and recreational athletes but is also becoming an integral part of healthcare and public health settings. However, despite the technological advancements and improved algorithms offering rich opportunities, wearables also face several obstacles. This review aims to highlight these obstacles, including the prerequisites for harnessing wearables to improve performance and health, the need for data accuracy and reproducibility, user engagement and adherence, ethical considerations in data harvesting, and potential future research directions. Researchers, healthcare professionals, coaches, and users should be cognizant of these challenges to unlock the full potential of wearables for public health research, disease surveillance, outbreak prediction, and other important applications. By addressing these challenges, the impact of wearable technology can be significantly enhanced, leading to more precise and personalized health interventions, improved athletic performance, and more robust public health strategies. This paper underscores the transformative potential of wearables and their role in advancing the future of exercise prescription, sports medicine and health.

Bridging exercises are commonly performed by people with low back pain (LBP). However, the effect of the contraction mode in a bridging exercise on the hemodynamics of the low back muscle has not been investigated in people with and without LBP. The objective of this study was to assess the effect of the mode of bridging exercise on oxygenation of the low back muscle. A near-infrared spectroscopy was used to measure hemodynamic responses of the erector spinae between isometric and dynamic bridging exercises in 16 healthy participants. The results demonstrated that during exercise, the isometric bridging exercise significantly decreased oxyhemoglobin and deoxy-hemoglobin compared to the dynamic bridging exercise (oxyhemoglobin, t=- 3.109, p=0.007, Cohen's d=0.68 and deoxy-hemoglobin, t=- 2.193, P=0.046, Cohen's d=0.60). The results also demonstrated that after exercise, the dynamic bridging exercise induced a significantly higher oxygenation response (oxygenation, t=- 2.178, P=0.048, Cohen's d=0.43). This study indicates that the dynamic bridging exercise is more effective in improving oxygenation of low back muscles.

Hydrogen, as an antioxidant, may have the potential to mitigate fatigue and improve selected oxidative stress markers induced by strenuous exercise. This study focused on a previously unexplored approach involving pre-exercise inhalation of hydrogen-rich gas (HRG). Twenty-four healthy adult men first completed pre-laboratories to determine maximum cycling power (W_max) and maximum cycling time (T_max). Then they were subjected to ride T_max at 80% W_max and 60-70 rpm on cycle ergometers after inhaled HRG or placebo gas (air) for 60-minute in a double-blind, counterbalanced, randomized, and crossover design. The cycling frequency in the fatigue modeling process and the rating of perceived exertion (RPE) at the beginning and end of the ride were recorded. Before gas inhalation and after fatigue modeling, visual analog scale (VAS) for fatigue and counter-movement jump (CMJ) were tested, and blood samples were obtained. The results showed that compared to a placebo, HRG inhalation induced significant improvement in VAS, RPE, the cycling frequency during the last 30 seconds in the fatigue modeling process, the ability to inhibit hydroxyl radicals, and serum lactate after exercise (p<0.028), but not in CMJ height and glutathione peroxidase activity. The cycling frequency during the last 30 seconds of all other segments in the fatigue modeling process was within the range of 60-70 rpm. In conclusion, HRG inhalation prior to acute exercise can alleviate exercise-induced fatigue, maintain functional performance, and improve hydroxyl radical and lactate levels.

Large cohort studies have reported that former professional football players have an increased risk of mortality from neurodegenerative disease. Due to emerging concerns regarding the safety of heading the technique is now banned for players under 12. The aim of this systematic review was to evaluate the association between heading exposure and cognitive function in professional football players. A search strategy was devised and entered into seven electronic databases: MEDLINE, Embase, Web of Science, PsycINFO, CENTRAL, SportDiscus and PEDro. The search identified 563 records. After screening records and applying the eligibility criteria, nine cross-sectional studies (n = 925) were included in the review, investigating 452 current and 473 former players (859 males, 66 females). Six studies (n = 595) reported evidence for an association between heading and impaired cognitive function, while three studies (n = 330) reported no association. Diverse cognitive domains were investigated, which might underline the disparity in these results. The association between heading and cognitive function in professional football appears likely but remains inconclusive. Methodological heterogeneity and variability in the presentation of results limits the conclusions drawn. Prospective longitudinal studies using standardised methods, and including females, are required to provide evidence to support or refute an association.

This study aimed to evaluate the applicability of the 10-minute submaximal treadmill test (T10 test), a self-paced test, in determining critical speed (CS) and predicting running performance. Specifically, we sought to identify the percentage of T10 velocity (vT10) that runners performed in official distance races, and to compare physiological and performance indicators between sexes. 60 recreational runners (n = 34 males and n = 26 females) underwent a maximum incremental test, the novel T10 test, and ran 1200-m and 2400-m on the track. Runners self-reported their best performance times. Generalized Linear Model was used to compare running performances between sexes. For both males and females, the %vT10 in 5km, 10km, and half-marathon races occurred at 107.5% and 106.5%, 99.9% and 100.8%, and 92.6% and 97.1%, respectively. There was no interaction effect (p = .520) and no main effect of sex (p = .443). There was a main effect of distance (p < .001), indicating that %vT10 in the 5km race differed from that found in the 10km race (p = .012), as well as in the half-marathon (p < .001). Our findings suggest that %vT10 values can be used to determine pace in recreational endurance runners for race distances regardless of sex.

This study aimed to investigate the applicability of the Lactate Threshold (LT) to predict maximal oxygen uptake (˙VO_2max) and demarcate the boundary between the moderate- to heavy-intensity domain (HR_m-h) in old age in comparison to the most utilized methods. A cross-sectional validation study was conducted. Participants aged 61 to 77 performed a familiarization procedure, an incremental maximal exercise treadmill test (CPX) for ˙VO_2max determination, the Six-minute Walk Test (6MWT), and a discontinuous incremental field test for LT determination. Lower (P<0.01) internal effort was required for LT testing (76±8%HR_max) compared to 6MWT (92±9%HR_max). The application of the 6MWT reference equations overestimated ˙VO_2max by 10-23%. LTs better estimated the ˙VO_2max (r ≈0.90, SEE: ≈3.0] compared to the 6MWT (r=0.68, SEE=5.5). HR_m-h determined by the CPX differed (20%; P=0.001) from that obtained by LT. HR_m-h stratification indicated participants fall into the very light to the vigorous intensity domains. LT testing is more submaximal than the 6MWT, and is a valuable tool to estimate the ˙VO_2max in older male adults. Implementation of LT testing in physical activity programs might help improving the quality of aerobic exercise training in older men.