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Suhara, H, Nariai, M, Takagi, T, Akiyama, K, Nagashima, J, and Shiraki, H. Relationship of clubhead speed with explosive power and muscle strength of the hip and trunk joints of elite golfers. J Strength Cond Res XX(X): 000-000, 2022-In golf, the driving distance of the ball is affected by the clubhead speed (CHS) on impact. We aimed to clarify the relationship between CHS and explosive power and muscle strength of the hip and trunk muscles in elite golfers (male age: 19.6 ± 1.9 years, male handicap: 4.4 ± 0.9, female age: 17.7 ± 1.4 years, and female handicap: 6.2 ± 0.7). A correlational design was used to assess the relationships between CHS and strength (hip extension-flexion and trunk rotation of peak torque at an isokinetic 60 and 180°·s-1 angular velocity) and CHS and power (countermovement jump [CMJ]; peak power and jump height; backward overhead medicine ball [BOMB] throw). Fourteen each of male and female elite golfers were included. The CHS during the golf swing was measured using a Doppler radar measurement device (Trackman). A correlation analysis between each measurement and CHS (p ≤ 0.05) was conducted. We found that the peak torque of right hip extension at an angular velocity of 180°/s (male, r = 0.67; female, r = 0.61), peak CMJ power (male: r = 0.63, female: r = 0.75), and BOMB throw distance (male, r = 0.6; female, 0.6) were positively correlated with CHS in both male and female golfers. These results suggest that the extensor strength of the lower extremities and trunk, centered on the hip joint in the sagittal plane, is important for physical fitness and muscle strength measurement related to CHS. Conversely, concentric trunk rotator strength and CHS were not correlated, suggesting that concentric trunk rotator strength may not be actively involved in CHS.

This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432). We conducted literature searches of PubMed and Ichushi-Web and used the Jonna Briggs Institute critical appraisal checklist to assess the quality. Of the 77 studies included in the meta-analysis, significant odds ratios (ORs) were obtained for eight factors associated with primary dysmenorrhea (PD): age ≥ 20 years (OR: 1.18; 95% confidence interval [CI]: 1.04–1.34), body mass index (BMI) < 18.5 kg/m2 (OR: 1.51; 95% CI: 1.01–2.26), longer menstrual periods (OR: 0.16; 95% CI: 0.04–0.28), irregular menstrual cycle (OR: 1.28; 95% CI: 1.13–1.45), family history of PD (OR: 3.80; 95% CI: 2.18–6.61), stress (OR: 1.88; 95% CI: 1.30–2.72), sleeping hours < 7 h (OR: 1.19; 95% CI: 1.04–1.35), and bedtime after 23:01 (OR: 1.30; 95% CI: 1.16–1.45). Two factors were associated with severity of PD (moderate vs. severe): BMI < 18.5 kg/m2 (OR: 1.89; 95% CI: 1.01–3.54) and smoking (OR: 1.94; 95% CI: 1.08–3.47). PD severity (mild vs. severe) and prevalence of premenstrual syndrome were associated with BMI < 18.5 kg/m2 (OR: 1.91; 95% CI: 1.04–3.50) and smoking (OR: 1.86; 95% CI: 1.31–2.66), respectively. The identified risk factors could be utilized to construct an appropriate strategy to improve menstrual symptoms and support women’s health.

Objective: In 2020, coronavirus disease-2019 (COVID-19) became the cause of a pandemic. In response, the Japan Sports Agency issued warnings about secondary damage to health, such as the threat to physical and mental well-being due to the lack of exercise in this situation. In this study, we report on cross-sectional and longitudinal examinations of standing trunk flexion to evaluate how temporary long-term school closures affected musculoskeletal function in elementary school students. Patients and Methods: All children in one public elementary school in T-city during the school years 2019 and 2020 were included in this study. A digital forward flexion meter was used to measure standing trunk flexion. Results: In this study, 284 (284/289: 98.3%) and 266 (266/274: 97.1%) children in school years 2020 and 2019, respectively, were found to have valid data for cross-sectional analysis. The standing trunk flexion did not show significant differences between grades or sexes. In the longitudinal analysis, the results of the comparison of standing trunk flexion in children for two consecutive years revealed significant differences only between grades 3 and 4 (P

OBJECTIVES Medial heel wedges are commonly prescribed to manage the weight-bearing response of hindfoot valgus and the total weight-bearing responses of the navicular and talus bones. Previous studies have reported that a medial heel wedge is effective in the management of musculoskeletal injuries. However, it remains unclear the effect of a medial heel wedge on the weight-bearing responses of footarch bones in vivo. To clarify the effects of a medial heel wedge on the weight-bearing response of hindfoot valgus and the total weight-bearing responses of the navicular and talus bones is necessary to understand how best to treat musculoskeletal injuries clinically. The purpose of our study was to clarify the effects of a medial heel wedge on the weight-bearing response of hindfoot valgus and the total weight-bearing responses of the navicular and talus bones.METHODS Twenty-five healthy males were analyzed. We obtained MRI scanning of the right foot under non-loading (NL) and full weight-bearing (FW) conditions. Participants wore two insole types, a flat insole and a medial heel wedge. To evaluate the weight-bearing response in hindfoot valgus, the hindfoot alignment view (HAV) was measured. We also measured navicular and talus bone positions and calculated the total positional changes of the navicular and talus bones (ΔTPCN, ΔTPCT) from the vertical and medial displacements using the Pythagorean theorem.RESULTS Significant interactions were observed with the HAV. Under both NL and FW conditions, the HAV was smaller on the medial heel wedge than on the flat insole. In addition, the ΔTPCN was significantly smaller on the medial heel wedge than on the flat insole. However, no significant differences were observed for ΔTPCT.CONCLUSIONS Our results suggest that use of a medial heel wedge decreases hindfoot valgus values under both NL and FW conditions and stabilizes the total weight-bearing response of the navicular bone.

Assessment of the total weight-bearing response of the navicular and talus bones is essential for evaluating the load absorption function. Although the weight-bearing response of the hindfoot valgus is likely related to the total weight-bearing response of the navicular and talus bones, this relationship is not well-understood. We evaluated the relationship between the total weight-bearing response of the navicular and talus bones and the weight-bearing response of the hindfoot valgus in the normal foot arch. Twenty-three males with normal foot arches were analyzed. We scanned the right foot of each participant under both non-loading and full weight-bearing conditions, using positional magnetic resonance imaging (pMRI). We measured the vertical and medial positions of the navicular and talus bones. The total positional changes of the navicular and talus bones (ΔTPCN and ΔTPCT, respectively) were calculated from the vertical and medial displacement values, using the Pythagorean theorem. To evaluate the weight-bearing response of the hindfoot valgus, the hindfoot alignment view (HAV) was measured. The difference in HAV (ΔHAV) between non-loading and full weight-bearing conditions was considered the weight-bearing response of the hindfoot valgus. Correlations between ΔTPCN, ΔTPCT, and ΔHAV were assessed using the Pearson correlation coefficient, and ΔTPCN and ΔTPCT were found to be moderately correlated with ΔHAV. Our study indicated that the total weight-bearing response of the navicular and talus bones correlated with the weight-bearing response of the hindfoot valgus in healthy adult males with normal foot arch.

The purpose of this study was to identify the dynamic factors contributing to pelvis angular velocity about its longitudinal axis (pelvis axial angular velocity) during the golf swing. Thirty-one right-handed skilled golfers (handicap, 3.5 ± 1.8) performed swings with a driver. The kinematic and kinetic data were collected using an optical motion analysis system and two force platforms. The dynamic factors (i.e., joint torque, gravitational force, motion-dependent forces and inertia forces) contributing to pelvis axial angular acceleration were calculated. The present study revealed that the left (lead) hip flexor and adductor torques as well as the right (trail) hip extensor and abductor torques were identified as the main contributors to pelvis axial angular velocity. These hip joint torques contributed not synchronously but sequentially to the pelvis. Although the knee joint torques contributed little to pelvis axial angular velocity directly, the knee joint torques might support the generation of large hip joint torques by regulating joint postures. These findings indicate that the functional coordination of the lower limb segments as well as the magnitude of the joint torques play an important role in rotating the pelvis.

Since clubface orientation at impact affects ball direction and ball spin, the ability to control clubface orientation is one of the most important skills for golfers. This study presents a new method to describe clubface orientation as a function of the clubshaft motions (i.e., swing plane orientation, clubshaft angle in the swing plane, and clubshaft rolling angle) during a golf swing and investigates the relationships between the clubshaft motions and clubface orientation at impact. The club motion data of driver shots were collected from eight skilled golfers using a three-dimensional motion capture system. The degrees of influence of the clubshaft motions on the clubface orientation were investigated using sensitivity analysis. The sensitivity analysis revealed that the swing plane horizontal angle affected the clubface horizontal angle to an extent of 100%, that the clubshaft angle in the swing plane affected both the clubface vertical and horizontal angles to extents of 74 and 68%, respectively, and that the clubshaft rolling angle affected both the clubface vertical and horizontal angles to extents of -67 and 75%, respectively. Since the method presented here relates clubface orientation to clubshaft motions, it is useful for understanding the clubface control of a golfer.

Akemi Sawai,1,* Bryan J Mathis,2,* Hiroaki Natsui,3 Alexander Zaboronok,2 Risa Mitsuhashi,1 Yuki Warashina,4 Noboru Mesaki,4 Hitoshi Shiraki,4 Koichi Watanabe4 1Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan; 2Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan; 3Faculty of Sports and Health Sciences, Japan Women’s College of Physical Education, Setagaya-ku, Tokyo, Japan; 4Faculty of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan *These authors contributed equally to this work Introduction: Menstrual dysfunction, musculoskeletal injury, and poor nutrition combine to form the female athlete triad (FAT), which results in serious health consequences for affected athletes. To this point, the risk factors of this phenomenon have not been fully explored in Japanese female college athletes. Additionally, the effect of competitive level on FAT risk factors has also not been reported. Therefore, we aimed to examine FAT risk factors in Japanese female athletes of various sports as well as examine the impact of competitive level on FAT.Methods: A Japanese-language survey was completed by 531 athletes and 20 nonathletes at two Japanese universities and answers with regard to menstrual status, musculoskeletal injury, nutrition, and other variables were analyzed based on classification of the sports into nine distinct groups based on activity type. Sport intensity, training volume, and competitive levels were used to further classify each sport. One-way ANOVA and the Bonferroni post hoc test using SPSS were carried out to analyze significance for relationships between sport intensity and FAT risk factors. Additionally, the relationship between competitive level and FAT risk factors was analyzed by ANOVA and Bonferroni post hoc tests.Results: Sport intensity was positively correlated with a delay in menarche as well as dysmenorrhea and poor nutrition while musculoskeletal injury was correlated with repetitive, high-training volume sports. Lower competitive levels increased dysmenorrhea but did not impact injury status or nutrition.Conclusion: Sport intensity and training volume, but not competitive level, are the critical factors affecting FAT risk in Japanese female college athletes. Keywords: athletes, dysmenorrhea, FAT, female, Japanese, triad

Single-legged drop jumps (SDJ), single-legged repetitive jumps (SRJ), and single-legged side hops (SSH) are often used as plyometric training and functional performance tests. Differences in the kinetics and kinematic characteristics of lower extremity joints during these jumps are unclear.The purpose of this study was to investigate the joint motion and mechanical work of the takeoff leg from foot contact to foot-off during SDJ, SRJ, and SSH in the sagittal and frontal planes in female athletes. It was hypothesized that the joint motion and mechanical work of the lower extremity joints during the SDJ and SRJ would be larger than the SSH in the sagittal plane, those during the SSH would be larger than the SDJ and SRJ in the frontal plane, and during SRJ would be larger than SDJ.Cross-sectional study.Seventeen female collegiate athletes participated and performed the SDJ (0.15-m box height), and SRJ and SSH (by crossing two lines 0.3 m apart). Three-dimensional coordinate data and ground reaction forces were collected. Contact time, jump height, jump index (i.e., the jump height divided by the contact time) of the SDJ and SRJ, and the total times of the SSH were calculated. Range of motion (ROM) from touchdown to the lowest center of mass, and the positive and negative (mechanical) work from touchdown to foot-off were analyzed.There were no significant differences in jump performance variables. Compared to the SSH, the SDJ and SRJ had significantly larger ankle and knee ROM and positive and negative work at the lower extremity joints, except for positive work at the hip joint, in the sagittal plane (p 0.05). Compared to the SDJ and SRJ, the SSH had a significantly larger ankle ROM and positive work at the knee joint in the frontal plane (p 0.05). Compared to the SDJ, the SRJ had a significantly larger ROM and negative work at each lower extremity joint in the frontal plane (p 0.05).Although there were no significant differences in the jump performance variables, different characteristics of the takeoff leg ROM and mechanical work were found between three kinds of rebound-type jump tests. These findings may help clinicians choose jump methods to assess lower extremity function and to design plyometric training programs in sports and clinical fields.3b.

Controlled laboratory study.To clarify whether differences in surface stability influence trunk muscle activity.Lumbar stabilization exercises on unstable surfaces are performed widely. One perceived advantage in performing stabilization exercises on unstable surfaces is the potential for increased muscular demand. However, there is little evidence in the literature to help establish whether this assumption is correct.Nine healthy male subjects performed lumbar stabilization exercises. Pairs of intramuscular fine-wire or surface electrodes were used to record the electromyographic signal amplitude of the rectus abdominis, the external obliques, the transversus abdominis, the erector spinae, and lumbar multifidus. Five exercises were performed on the floor and on an unstable surface: elbow-toe, hand-knee, curl-up, side bridge, and back bridge. The EMG data were normalized as the percentage of the maximum voluntary contraction, and data between doing each exercise on the stable versus unstable surface were compared using a Wilcoxon signed-rank test.With the elbow-toe exercise, the activity level for all muscles was enhanced when performed on the unstable surface. When performing the hand-knee and side bridge exercises, activity level of the more global muscles was enhanced when performed on an unstable surface. Performing the curl-up exercise on an unstable surface, increased the activity of the external obliques but reduced transversus abdominis activation.This study indicates that lumbar stabilization exercises on an unstable surface enhanced the activities of trunk muscles, except for the back bridge exercise.

PURPOSE: To determine the patterns of electromyographic (EMG) responses and torques of upper extremity muscles in overhead throwers during maximal, eccentric muscle action for shoulder flexion (Flex_), abduction (Abd_) and diagonal activities (Dia_) with full glenohumeral internal rotation, at 60, 120, and 180°/s on the dynamometer. METHODS: Seven asymptomatic subjects (7 men, 4 women) who participate in overhead sports at least three days a week volunteered to participate in this study. Subjects were randomly performed with the test procedure which consisted of at least 5 grade maximal-effort repetitions on the three different testing conditions, at 60, 120, and 180°/s on the dynamometer, while we assessed muscle activation of the anterior deltoid (AD), middle deltoid (MD), posterior deltoid (PD), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and biceps brachii (BB) muscles by surface electromyography. EMG data was expressed as a percentage of maximum voluntary isometric contraction (%MVIC) that was obtained from the highest root mean square (RMS, 50ms) of each muscle and was normalized and averaged. RESULT: AD muscle elicited lower muscle activity during Dia_ than Flex_ and Abd_, (P. MD and MT muscle activities were significantly greater for the faster speed than for the slower speed as 60°/s during Abd_(P than Flex_, and Abd_, and it was significantly greater for the faster speed than slower speed during Dia_ (P

application/pdf, Purpose: This study was to investigate the patterns of electromyography (EMG) amplitude responses during maximal, eccentric muscle action with shoulder adduction and diagonal movement, at 6 different positions on the dynamometer. Methods: The participants for this investigation were 9 males and 5 females. Testing consisted of each subject performing eccentric muscle exercise of the dominant shoulder muscle at a velocity of 60°/sec and 180°/sec. Muscle activity values was recorded individually from six different muscles and peak torque values were extracted for each test from torque curves once. EMG data were normalized to the highest root mean square (RMS), and were expressed as a% maximum voluntary isometric contraction (%MVIC). Results: The posterior parts of upper extremity muscle complex generate overall high muscle activity (>40%MVIC) during all testing for eccentric muscle activity with diagonal shoulder movement. Posterior deltoid (PD), upper trapezius (UT), and middle trapezius (MT) muscles show differences between eccentric muscle action with shoulder adduction and eccentric muscle action with diagonal shoulder movement. Conclusion: The present results show that an improved understanding of muscle activity patterns during different movement may benefit many fields of athletic trainers, coaches, and athletes, in addition to assisting in injury prevention for throwers, and even rehabilitation after injury.

The aim of this study was to investigate the immediate effects of trunk stabilization exercise (SE) and conventional trunk exercise (CE) programs on jump performance. 13 adolescent male soccer players performed 2 kinds of jump testing before and immediate after 3 experimental conditions: SE, CE, and non-exercise (NE). The SE program consisted of the elbow-toe, hand-knee, and back bridge, and the CE program consisted of the sit-up, sit-up with trunk rotation and back extension. Testing of a countermovement jump (CMJ) and rebound jump (RJ) were performed to assess jump performance. Jump height of the CMJ and RJ-index, contact time, and jump height of the RJ were analyzed. The RJ index was improved significantly only after SE (p=0.017). However, contact time and jump height did not improve significantly in the SE condition. Moreover, no significant interaction or main effects of time or group were observed in the CMJ. Consequently, this study showed the different immediate effect on the RJ between the SE and CE, and suggested the possibility that the SE used in this study is useful as a warm-up program to improve the explosive movements.

Professional golfers travel extensively during the tournament season, making it difficult to maintain their health and physical strength. Such problems as menstrual disorders and low bone mineral density have been reported with female athletes, and the difficulty of maintaining a good physical condition has been pointed out.This study investigates the current condition of professional female golfers with regard to their physical health and eating habits as the first step in devising a regimen to improve their physical condition. A questionnaire survey of such aspects as physical characteristics, food intake frequency, health condition, and nutrition was conducted on 104 professional female golfers. A total of 60 responses (58%) were usable and demonstrate a deterioration of physical condition during the tournament season. The respondents also expressed a desire to acquire information about nutrition from a dietitian or doctor.

The goal of our studies is to examine the mechanism of the muscle output of the shoulder joint. In this paper we compared and quantified electromyographic muscle activities and the onset order of the rotator cuff and shoulder superficial muscles in relation to the change in concentric torque generated by performing shoulder external rotation.Twenty-four healthy male subjects (mean age 23.3) without any history of shoulder injury participated in the experiments. A Cybex 770 dynamometer was used to control the load and the angle of motion; the range of loads was 0-18 Nm, the range of motion was 75-0 degrees of internal rotation, and the angular velocity of the movements was fixed at 15 deg/sec. Electromyographs (EMGs) were recorded using surface electrodes placed on the shoulder superficial muscles and intramuscular wire electrodes from the rotator cuff. The raw EMG signals for each load were separated into five equal parts (each covering 15 degrees), which were then separately rectified and integrated. The integrated EMG data, which was normalized against data for maximum voluntary contraction, was compared for each load and each angle condition.The results of this experiment clearly showed that the supraspinatus (SSP), middle deltoid (MD), and middle trapezius (MT), as well as infraspinatus (ISP), teres minor (TM), and posterior deltoid (PD) muscles took part in external rotational movements. The EMG-onsets of the rotator cuff were generally faster, and their muscle activities were greater, than in the superficial muscles. For each muscle, however, the degree of participation was markedly dependent on the load and angle of motion.The EMG-onset of the ISP was the fastest, and the muscle activity of the ISP was the highest of all muscles, irrespective of load or angle of motion. It is thus certain that the ISP plays an important role as both a stabilizer and a mover during external rotational movement. At low loads, the TM demonstrated a pattern of muscle activity similar to that of the ISP, but it was notable that muscle activity did not increase for loads greater than 30-40% MVC. On the other hand, the muscle activity of the SSP was lower than that of the TM in the area approaching full internal rotation and at low loads. As the load increased, however, muscle activity of the SSP became higher than that of the TM. The TM and the SSP, therefore, may have different functional roles depending on the situation; both muscles may contribute to external rotational movements as the supporting mover.The muscle activity of the MD was higher than that of the PD in the area approaching full internal rotation. Clearly, not only the PD but the MD also takes part in external rotational movements, depending on the angle of motion. The EMG-on-set of the MT was faster, and the muscle activity of the MT at low loads was higher, than seen in other superficial muscles. Moreover, the activity of the MT increased with increasing load and degree of external rotation. These results suggest that the MT assists the mover muscles by anchoring the scapula at low loads but adducting it at high loads and in the area of external rotation.

Choi, Y, Akazawa, N, Zempo-Miyaki, A, Ra, S-G, Shiraki, H, Ajisaka, R, and Maeda, S. Acute effect of high-intensity eccentric exercise on vascular endothelial function in young men. J Strength Cond Res 30(8): 2279-2285, 2016-Increased central arterial stiffness is as an independent risk factor for cardiovascular disease. Evidence regarding the effects of high-intensity resistance exercise on vascular endothelial function and central arterial stiffness is conflicting. The purpose of this study was to examine the effects of acute high-intensity eccentric exercise on vascular endothelial function and central arterial stiffness. We evaluated the acute changes in endothelium-dependent flow-mediated dilation (FMD), low-flow-mediated constriction (L-FMC), and arterial stiffness after high-intensity eccentric exercise. Seven healthy, sedentary men (age, 24 ± 1 year) performed maximal eccentric elbow flexor exercise using their nondominant arm. Before and 45 minutes after eccentric exercise, carotid arterial compliance and brachial artery FMD and L-FMC in the nonexercised arm were measured. Carotid arterial compliance was significantly decreased, and β-stiffness index significantly increased after eccentric exercise. Brachial FMD was significantly reduced after eccentric exercise, whereas there was no significant difference in brachial L-FMC before and after eccentric exercise. A positive correlation was detected between change in arterial compliance and change in FMD (r = 0.779; p ≤ 0.05), and a negative correlation was detected between change in β-stiffness index and change in FMD (r = -0.891; p < 0.01) with eccentric exercise. In this study, acute high-intensity eccentric exercise increased central arterial stiffness; this increase was accompanied by a decrease in endothelial function caused by reduced endothelium-dependent vasodilation but not by a change in endothelium-dependent vasoconstriction.

Summary.-Many studies of the psychological effects of physical location in small discussion groups and classrooms have indicated that seating positions in groups or classrooms are related to participation, personality, or perception. In this preliminary study, environmental perception of several positions occupied by Japanese participants and preference for location in a golf-practice situation were investigated. Analyses indicated that different positions in a group were differently perceived and that certain positions were preferred over others and the main reason for the preference was related to visibility. Such information could be useful for instructors in making a psychologically comfortable environment during golf practice. So far, a considerable number of studies have been made of the psychological associations of seating location in discussion groups or classroom situations (see Baker, 1984; Montello, 1988). These studies suggest that seating location in groups is related to participation in discussion or perception of participants (e.g., Caproni, Levine, O'Neal, McDonald, & Garwood, 1977; Pedersen, Polson, & Hinze, 1987), while, in sports sciences, the relation of playing positions in team sports to managerial recruitment has been discussed (e.g., Grusky, 1963). However, little research on the psychological meanings of the location occupied by participants in sports practice situations has been made, except Haber (1982) conducted a pilot study of spacing behavior in exercise and dance classes. It seems necessary to investigate the relations between participants' spacing behavior and various psychological variables in various sporting situations so that instructors could understand the effects of physical location on psychological states or learning and organize effective group lessons. In this paper, as a preliminary study of spacing behavior in sport practice, perception of several different positions occupied by learners, preference for playing positions, and its reason in a golf-practice situation were investigated. METHOD Subjects were 51 students (36 men, 15 women) from a Japanese university who participated in golf classes. Their mean age was 19.5 yr. (SD = 0.9). They were novice golfers because most subjects had never experienced golf except in the classes. All were observed to play golf right-handed during practice sessions.

Background: Endurance exercise training decreases arterial stiffness, whereas high-intensity strength exercise training increases arterial stiffness. However, the mechanisms underlying the adaptations to the 2 types of exercise training remain unclear. Increased oxidative stress induces vasoconstriction and endothelial dysfunction. Plasma advanced oxidation protein products (AOPP)—a novel marker of oxidative stress—have recently been reported to be positively associated with arterial stiffness in healthy subjects. We hypothesized that AOPP are involved in the adaptation of arterial stiffness in different types of exercise training. Methods: We investigated plasma AOPP concentration and arterial stiffness in strength- and endurance-trained athletes. The subjects included young strength-trained athletes (SA group) (shot put, hammer, or javelin throwers; n = 12), endurance-trained athletes (EA group) (long- or middle-distance runners; n = 10), and sedentary individuals (Control group) (n = 12). We measured aortic pulse-wave velocity (PWV), systemic arterial compliance (SAC), and plasma AOPP concentrations. Results: PWV was higher in the SA than in the EA or control groups (SA: 6.48 ± 0.47, EA: 6.00 ± 0.67, Control: 5.65 ± 0.52 m/s, mean ± SD), and SAC was lower in the SA than in the EA or control groups (SA: 1.04 ± 0.24, EA: 1.56 ± 0.44, Control: 1.38 ± 0.35 ml/mmHg); thus, arterial stiffness was higher in the SA group. Plasma AOPP concentrations were higher in the SA group than in the EA group (SA: 31.7 ± 8.5, EA: 23.9 ± 6.9, Control: 27.2 ± 3.9 μmol/l). We found that plasma AOPP levels tended to be related to SAC (P = 0.073, r = −0.31). Conclusions: The present study provides a possibility that exercise training-induced oxidative stress may be partly involved in the mechanism underlying the adaptation of arterial stiffness in strength- and endurance-trained athletes.

Background: Endurance exercise training decreases arterial stiffness, whereas high-intensity strength exercise training increases arterial stiffness. However, the mechanisms underlying the different adaptations to these two types of exercise training are unclear. Oxidative stress induces vasoconstriction and endothelial dysfunction. Recently, plasma advanced oxidation protein products (AOPP), a new marker of oxidative stress, level has been reported to be positively associated with arterial stiffness in healthy subjects. We hypothesized that AOPP participates in the adaptation of arterial stiffness in different types of exercise training. The purpose of this study was to investigate plasma AOPP concentration and arterial stiffness in strength- and endurance-trained athletes. Methods: Young male strength-trained athletes (shot put, hammer, or javelin throwers; n=12; SA), endurance-trained athletes (long- or middle-distance runners; n=10; EA), and sedentary control human (n=12; C) participated in this study. We measured maximal handgrip strength, maximal oxygen uptake, aortic pulse wave velocity (APWV), which is an index of arterial stiffness, and plasma AOPP concentration. Results: Maximal handgrip strength was significantly greater in SA compared with C and EA. Maximal oxygen uptake was significantly greater in EA compared with C and SA. APWV was significantly higher in SA compared with C and EA. Plasma AOPP concentration was significantly higher in SA compared with in EA. The relationships of plasma AOPP concentrations to maximal handgrip strength (i.e., muscle strength) and maximal oxygen uptake (i.e., aerobic capacity) were linear (AOPP and muscle strength: r=0.42, AOPP and aerobic capacity: r= -0.46). Conclusion: The present study suggests that oxidative stress may participate in the mechanism underlying different adaptations of arterial stiffness in strength- and endurance-trained athletes. Key words: arterial stiffness; oxidative stress; endurance exercise training; strength exercise training