Journal of Physical Fitness and Sports Medicine
Official journal of the Japanese Society Physical Fitness and Sports Medicine
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The Journal of Physical Fitness and Sports Medicine (JPFSM)
[Volume 13, Number 3 May 25, 2024]
Review Article
- Received: October 11, 2023 / Accepted: December 1, 2023
Abstract
Resistance exercise may empirically be believed to cause acutely increases in passive muscle stiffness in sports and rehabilitation. The acute increase in muscle stiffness limits the joint range of motion (ROM) and may indirectly increase the risk of musculoskeletal injuries and impair athletic performance in some sports events. Thus, a comprehensive understanding of resistance exercise-induced acute changes in passive muscle stiffness is essential in sports and clinical settings. Many studies have investigated acute changes in passive muscle stiffness after resistance exercise. However, no clear consensus has been reached, possibly because of differences in program variables (e.g., contraction mode, exercise ROM, and load) among studies. The present review aimed to provide an overview of the types of resistance exercises with different combinations of program variables that induce acute or insignificant changes in passive muscle stiffness (shear modulus assessed by ultrasound shear wave elastography). This review suggests that 1) muscle stiffness is acutely increased by eccentric-only resistance exercise with a combination of a wide ROM, a high load, and a high volume; 2) muscle stiffness is acutely decreased by eccentric-only resistance exercise with a combination of a wide ROM, long muscle lengths, and a long duration when exercise is performed with a low to moderate load and/or volume; 3) muscle stiffness does not acutely change after concentric-only resistance exercise; and 4) acute changes in stiffness after resistance exercise depend on measured muscles, joint positions, and time points.
Regular Article
- Received: October 4, 2023 / Accepted: December 26, 2023
Abstract
Whether decreases in adipose and lean tissue during body weight (BW) reduction differ between males and females is unclear. To investigate sex differences in changes in body composition and energy deficits during BW reduction, sexually mature 15-week-old rats were divided into a group euthanized before BW reduction (n = 6 males, n = 7 females) and a group euthanized after three days of fasting (n = 6 males, n = 6 females). Energy expenditure and BW were measured during the study period. Losses of lean tissue (ΔLT) and adipose tissue (ΔAT) were calculated using simultaneous equations based on ΔBW, which is the sum of ΔLT and ΔAT, and the energy lost from the body is the sum of the energy lost from ΔLT and ΔAT. BW reduction was significantly greater in males than in females, total energy expenditure was significantly greater in males than in females, and the energy required to reduce BW by 1 kg was significantly less in males (3304.8 kcal/kg [SD 327.5]) than in females (3893.0 kcal/kg [SD 356.5]). Both ΔLT and ΔAT were significantly greater in males than in females. The ΔLT:ΔAT ratio was significantly different between males (67:33) and females (57:43). Sex differences exist in the metabolic responses to BW reduction, and females lose more energy-dense adipose tissue during BW reduction than males, demonstrating that a greater energy deficit is required to reduce BW in female rats than in male rats.
Regular Article
- Received: October 25, 2023 / Accepted: January 5, 2024
Abstract
Excess accumulation of visceral fat induces insulin resistance in skeletal muscle and impairs glucose tolerance. Although weight loss improves glucose tolerance by reducing visceral fat mass, the effects of the speed of weight loss on glucose metabolism are unclear. This study compared the effects of long-term energy restriction–induced weight loss and short-term fasting–induced weight loss on glucose tolerance in rats fed a high-fat diet. After 2 weeks of high-fat diet feeding, male Wistar rats were subjected to either 30% calorie restriction for 2 weeks (CR) or 3-day fasting (FAST). After the intervention period, body weight and intra-abdominal fat mass decreased to a similar extent in both weight-loss groups. The maximum insulin-stimulated glucose uptake and GLUT-4 content in the epitrochlearis muscle were significantly higher in the FAST group than in both control rats fed ad libitum (CON) and the CR group, with no significant differences between the CON and CR groups. Blood glucose levels during the oral glucose tolerance test (OGTT) were similar in the CON and CR groups, but insulin levels were significantly lower in the CR group than in the CON group, indicating improved insulin resistance in the CR group. However, compared with the CON and CR groups, plasma glucose and insulin levels were significantly higher and lower, respectively, in the FAST group during the OGTT. These findings suggest that rapid weight loss through short-term fasting, in contrast to long-term energy restriction, may impair glucose tolerance by reducing insulin secretion capacity.
[Volume 13, Number 4 July 25, 2024] Special Issue
Review
- Received: August 17, 2023 / Accepted: September 11, 2023
Abstract
The purpose of this narrative review is to outline pelvic injuries caused by sports, and to clarify their trends, treatment, and management. We describe the rehabilitation for sports injuries of the pelvis, with a focus on pelvic avulsion injuries and pelvic bone stress fractures. This narrative review of fifteen articles published in the last 10 years (from 2013 to 2023) reveals a dearth of new rehabilitation knowledge regarding sports-induced pelvic injuries.
Review
- Received: August 8, 2023 / Accepted: September 11, 2023
Abstract
This review is based on the literature published between 2000 and 2023 and presents an up-to-date evidence-based discussion of anatomical considerations relevant to the management of pelvic trauma. In addition, it discusses the significance of the pelvic ligaments in stabilizing the pelvic ring and of bone mineral density (BMD) in fragility fracture of the pelvis (FFP), which is becoming increasingly common in today’s aging societies. Following an overview of the anatomy and function of the sacroiliac joint (SIJ), the pubic symphysis, and the surrounding ligaments, the suitability of the widely used Young-Burgess classification of high-energy impact pelvic ring fractures, which emphasizes the role of the ligaments in pelvic ring injuries, is discussed. Based on the current body of knowledge, using 2.5 cm of pubic symphysis diastasis as the determinant for surgical intervention for anterior-posterior compression fracture is questioned, and evaluation under anesthesia and lateral stress radiography for accurate diagnosis and treatment planning is proposed instead. The review underscores the need for further research on how the pelvic ligaments can provide optimal stability in the treatment of various types of pelvic fracture. On the other hand, for fragility fracture of pelvis (FFP) in older adults caused by low-energy trauma, the emphasis is on the fragility of the bones. To better manage FFP, the importance of understanding the distribution of BMD in the pelvis is highlighted. Dual-energy X-ray absorptiometry is a common method for measuring BMD, but it has drawbacks. The advantages of measuring BMD using Hounsfield units on computed tomography scans as an alternative method are discussed. An understanding of these issues may lead to better management of the increasing number of FFP cases in older people with reduced BMD.
Review
- Received: December 11, 2023 / Accepted: February 13, 2024
Abstract
Pelvic fractures, accounting for 2–8% of skeletal injuries, present a significant burden in patients with trauma. High-energy incidents often result in severe pelvic trauma accompanied by comorbidities leading to high mortality rates. Managing these complications adds complexity to the treatment process, particularly in older patients who experience longer recovery times and higher injury severity. To improve the long-term quality of life, a multidisciplinary approach is essential. However, rehabilitation feasibility is influenced by the patient’s condition and pelvic fixation stability, necessitating individualized treatment. This study investigated the rehabilitation status and long-term outcomes of older patients with severe polytrauma and pelvic ring fractures caused by high-energy trauma. The results revealed that 79.2% of the patients achieved full weight-bearing, with a median time of 41.5 days, and eventually 58.3% were discharged home. Complications were observed in 83.3% of the patients, with various challenges affecting successful home discharge. Multidisciplinary rehabilitation programs are promising for optimizing outcomes and facilitating recovery in vulnerable patient populations. Still, larger, more focused studies are needed to gain more comprehensive insights into the treatment and recovery of older patients with pelvic ring fractures and severe polytrauma. Understanding these factors is crucial for guiding clinical decision-making and improving long-term outcomes in this population.
Regular Article
- Received: December 11, 2023 / Accepted: February 13, 2024
Abstract
Pelvic fractures, accounting for 2–8% of skeletal injuries, present a significant burden in patients with trauma. High-energy incidents often result in severe pelvic trauma accompanied by comorbidities leading to high mortality rates. Managing these complications adds complexity to the treatment process, particularly in older patients who experience longer recovery times and higher injury severity. To improve the long-term quality of life, a multidisciplinary approach is essential. However, rehabilitation feasibility is influenced by the patient’s condition and pelvic fixation stability, necessitating individualized treatment. This study investigated the rehabilitation status and long-term outcomes of older patients with severe polytrauma and pelvic ring fractures caused by high-energy trauma. The results revealed that 79.2% of the patients achieved full weight-bearing, with a median time of 41.5 days, and eventually 58.3% were discharged home. Complications were observed in 83.3% of the patients, with various challenges affecting successful home discharge. Multidisciplinary rehabilitation programs are promising for optimizing outcomes and facilitating recovery in vulnerable patient populations. Still, larger, more focused studies are needed to gain more comprehensive insights into the treatment and recovery of older patients with pelvic ring fractures and severe polytrauma. Understanding these factors is crucial for guiding clinical decision-making and improving long-term outcomes in this population.
[Volume 13, Number 5 September 25, 2024]
Short Review Article
- Received: November 27, 2023 / Accepted: January 23, 2024
Abstract
About half of young Japanese women have a cold constitution, which heightens susceptibility to cold syndrome. In recent years, new findings on the physiological features of a cold constitution have increased. Cold constitution lowers the quality of daily life, so coldness and the related complaints need to be alleviated. Single dynamic exercise transiently relieves coldness via the warm-up effect. Exercise training decreases sensitivity to cold under normal temperature conditions and enhances peripheral cutaneous vasodilatory responses in young women with a cold constitution. This review provides an overview of the physiological characteristics of women’s cold constitution and the acute and chronic effects of physical exercise as a countermeasure.
Regular Article
- Received: August 4, 2023 / Accepted: February 7, 2024
Abstract
This study examined the effects of distractions on ratings of perceived exertion (RPE) and affective responses during acute high intensity cycling exercises. Eighteen young males (age: 22.2±1.7 years) visited the laboratory on four sessions. Participants performed three experimental trials following an incremental maximal test. During the three trials, participants performed cycling exercises at 70% VO2max for 20 min under three conditions: control, active distraction, and involuntary distraction. The participants rated their overall and peripheral RPE at 5 min intervals during the 20 min cycling period. Participants’ affective responses were assessed before and after cycling including positive engagement (PE), negative affect (N-affect), and tranquility. There were no significant differences in RPEs among the three conditions. For affective responses, a significant main effect of condition was seen only for N-affect. This study suggested that active and involuntary distractions do not influence perceived exertion when participants perform 20-min vigorous-intensity exercises. One possible reason for the result is that inadequate method used as active distraction. Further research is required to examine the appropriate methods that promote distraction from bodily sensations during high-intensity exercise.
Regular Article
- Received: November 16, 2023 / Accepted: February 16, 2024
Abstract
Early cardiopulmonary resuscitation (CPR) intervention is critical for saving individuals experiencing sudden cardiac arrest. Manikins are considered useful for CPR training, but their level of realism is low, given the visible structural differences in the chests of biological men and women. However, to our knowledge, no study has examined whether a patient’s sex has an impact on the performance of chest compression. Therefore, this study aimed to investigate the quality of chest compressions in female patients, in relation to the rescuers’ posture. This single-center cross-sectional study was conducted from July to October 2023 on 34 healthcare professional university students. Two postures for chest compression were analyzed: 1) kneeling beside the patient’s chest (conventional compression) and 2) straddling the patient (straddle compression). The mean age of the 34 participants (18 men and 16 women) was 21.2±0.6 years. Significant differences were found in mean compression depth (p = 0.005) and appropriate compression ratio (p = 0.013) between the conventional and straddle compression but not in other parameters. In conclusion, the rescuers’ posture during chest compression in female patients affects the compression depth and depth ratio. The straddle compression may facilitate the provision of well-balanced compressions of appropriate depth and depth ratio. These findings can be applied to CPR training and provide guidance for administering chest compressions to female patients.
[Volume 14, Number 1 January 25, 2025]
Regular Article
- Received: October 4, 2023 / Accepted: February 28, 2024
Abstract
Arm-cranking exercises combined with electrical muscle stimulation (EMS) of the lower limbs at maximum intensity enhance vascular endothelial function. To bring this procedure into clinical application, we examined the effects of acute arm-cranking exercise combined with lower-extremity EMS at different intensities on vascular endothelial function. The study included eight healthy adult males. After resting in the supine position, arm-cranking exercises were performed at an intensity of 50% VO2 max for 20 min, and the lower limb received EMS under three trials: maximum intensity trial (A+100%EMS trial), 50% intensity trial (A+50%EMS trial), and 25% intensity trial (A+25%EMS trial). Flow-mediated dilation (FMD), which reflects vascular endothelial function, was measured before and after the procedure, and the normalized FMD (nFMD) was calculated. The mean nFMD before and 30 min after the exercise was 0.8±0.3 and 2.3±1.8, respectively, in the A+100%EMS trial and 0.9±0.4 and 1.4±1.0, respectively, in the A+50%EMS trial, indicating a significant increase after exercise under both trials. No changes were observed in the A+25%EMS trial. The combination of arm-cranking exercise and 50% intensity EMS appears to be a clinically applicable program for improving vascular endothelial function, even with reduced exercise intensity.
Short Communication
- Received: February 1, 2024 / Accepted: April 1, 2024
Abstract
Weight loss reduces visceral fat and improves glucose tolerance. Our previous study found that weight loss from 3 consecutive days of fasting led to deteriorated glucose tolerance, but it is not clear whether this was due either to the physiological stress associated with consecutive fasting or that fasting itself. This study aimed to compare the effects of repetitive or consecutive fasting on intra-abdominal fat mass and glucose tolerance in rats fed a high-fat diet. After 2 weeks of high-fat diet feeding, male Wistar rats were divided into three groups matched for body weight: one group continued to receive the high-fat diet ad libitum for 2 weeks (control, CON); the second group fasted for the last 3 days (consecutive fasting, CF); and the third group repeated 1-day fasting three times with a 6-day ad libitum feeding interval (repetitive fasting, RF). Compared with the CON group, the intra-abdominal fat mass was significantly lower in the CF group after the intervention period, and there was a tendency for lower values in the RF group. During the oral glucose tolerance test, plasma glucose level was significantly higher in both fasting groups compared with the CON group, while that in the CF group was significantly higher than that in the RF group. Compared with the CON group, the CF group had significantly lower plasma insulin level, with a tendency for lower levels in the RF group. These findings suggest that even when fasting days are dispersed over multiple occasions, insulin secretion capacity may decrease in a similar manner to consecutive fasting, leading to a deterioration in glucose tolerance.
Regular Article
- Received: December 26, 2023 / Accepted: April 23, 2024
Abstract
The mitochondria are highly plastic organelles. Exercise training alters mitochondrial dynamics (mitochondrial fission and fusion) in skeletal muscles and improves overall mitochondrial function by altering mitochondrial morphology and forming new networks. However, changes in mitochondrial dynamics over time during exercise have not previously been observed. In the present study, we examined the changes in mitochondrial fission and fusion protein expression in rats over four weeks of endurance swimming training. The expression of the GTPase protein dynamin-related protein 1 (Drp1), a mitochondrial fission protein, increased during the early phase of the training period. In contrast, the expression of optic atrophy type 1 (OPA1), a mitochondrial fusion protein, was increased in the late phase of the training period. These data suggest that mitochondrial fission was increased in the early phase, and mitochondrial fusion was initiated partially in the late phase, of the training period. In conclusion, mitochondrial dynamics may be modulated depending on the phase of muscular adaptation to exercise training. This modulation contributes to enhanced mitochondrial function in skeletal muscle.
[Volume 14, Number 2 March 25, 2025]
Regular Article
- Received: January 15, 2024 / Accepted: April 24, 2024
Abstract
Glucose has been reported to reduce the expression of L-type amino acid transporter 1 (LAT1) protein in C2C12 myocytes. We therefore hypothesized that increased dietary carbohydrate and energy intake would reduce LAT1 protein expression in rodent skeletal muscle. Here, we tested this hypothesis. In Experiment 1 to examine the effects of dietary carbohydrate intake, male Sprague Dawley (SD) rats were divided into low-carbohydrate (low-CHO) and high-carbohydrate (high-CHO) diet groups. Each group was fed a low-CHO (20% carbohydrate) or high-CHO (70% carbohydrate) diet, respectively. Total energy intakes of both groups were matched by pair feeding. In Experiment 2 to examine the effects of dietary energy intake, rats were divided into low-Energy diet (fed 68% of ad libitum energy intake) and high-Energy diet (ad libitum) groups. After 7 days of dietary manipulation, the lower leg muscles on one side were percutaneously stimulated and subjected to one acute bout of resistance exercise. The contralateral leg muscle served as an internal control. We collected gastrocnemius muscle 6 h after contraction. In both Experiments 1 and 2, when results were analyzed by two-way analysis of variance, no main effect of diet on LAT1 protein concentration was observed. There was also no main effect of resistance exercise, or no interaction between diet and exercise. These results do not support our hypothesis that increased dietary carbohydrate and energy intake reduce LAT1 protein expression in rodent skeletal muscle. Furthermore, diet may not affect the effects of resistance exercise on LAT1 protein expression.
Regular Article
- Received: January 26, 2024 / Accepted: April 24, 2024
Abstract
This study aimed to prospectively record the occurrence of adverse events and near-misses during sports in middle-aged and older adults who voluntarily engaged in sports in the community and to clarify the frequency and characteristics of such events. The participants comprised 14 groups (14 sports) of middle-aged and older adults who voluntarily played sports in Sakae Ward, Yokohama. The follow-up period was 14 months (November 1, 2022, to December 31, 2023). Representatives of the target groups reported once a month to Sakae Ward via postcards regarding the status of their activities and the occurrence of adverse events and near-misses. The survey items included the age of the main participants in each group, number of activities during the month, duration of each activity, number of participants per activity, adverse events, and near-misses during sports. During the 14-month observation, eight adverse events and two near-misses were reported in the 14 groups, mainly comprising middle-aged and older adults. Of the eight adverse events, four were falls, all occurring in those aged ≥70 years and triggered by environmental problems. In this study, there were only two near-misses compared to eight adverse events, suggesting that the participants may have been unaware of near-misses. Therefore, even for sports played by groups of residents, it is important to identify risks by assessing health conditions prior to exercise and to implement initiatives to foster safety awareness among participants, such as hazard prediction training.