Differences of Bone Mineral Density by Characteristics of Sports in Amenorrheic Athletes.

Hypothalamic amenorrhea leads to a hypoestrogenic state, causing decreased bone mineral density (BMD), while strong impact loading on bone has been shown to increase BMD. The purpose of this study is to compare BMD in female athletes based on menstrual status and their sports/events by impact loading characteristics. BMD at the lumbar spine was measured by dual-energy X-ray absorptiometry and hormone level. The subjects were classified into four groups and BMD and hormone levels were compared among the four groups, which were divided into amenorrheic athletes (AAs) and eumenorrheic athletes (EAs). This study recruited 410 female athletes (164 in the AAs and 246 in the EAs), 55 athletes in non-impact sports, 123 in low-impact sports, 141 in multidirectional sports, and 91 in high-impact sports. In the AAs group, BMD Z-score was lowest in low-impact sports (Z-score: -1.53 [-1.76, -1.30]), and was highest in high-impact sports (Z-score: 0.02 [-0.34, 0.38]). In multidirectional and high-impact sports, BMD Z-score in the AAs group did not show results lower than the average for non-athletes. When screening female athletes for low BMD, it is important to evaluate the risk of low BMD based on the impact loading characteristics of their sports/events, in addition to the menstrual state.

Football-specific extension of the IOC consensus statement: methods for recording and reporting of epidemiological data on injury and illness in sport 2020.

Several sports have published consensus statements on methods and reporting of epidemiological studies concerning injuries and illnesses with football (soccer) producing one of the first guidelines. This football-specific consensus statement was published in 2006 and required an update to align with scientific developments in the field. The International Olympic Committee (IOC) recently released a sports-generic consensus statement outlining methods for recording and reporting epidemiological data on injury and illness in sport and encouraged the development of sport-specific extensions.The Fédération Internationale de Football Association Medical Scientific Advisory Board established a panel of 16 football medicine and/or science experts, two players and one coach. With a foundation in the IOC consensus statement, the panel performed literature reviews on each included subtopic and performed two rounds of voting prior to and during a 2-day consensus meeting. The panel agreed on 40 of 75 pre-meeting and 21 of 44 meeting voting statements, respectively. The methodology and definitions presented in this comprehensive football-specific extension should ensure more consistent study designs, data collection procedures and use of nomenclature in future epidemiological studies of football injuries and illnesses regardless of setting. It should facilitate comparisons across studies and pooling of data.

Effect of transdermal estradiol therapy on bone mineral density of amenorrheic female athletes.

BACKGROUND: The effects of transdermal estradiol treatment (HT) in amenorrheic athletes (AA) with low body weight (BW) and low bone mineral density (BMD) are unknown. PURPOSE: To investigate whether HT increases BMD in AA with low BW and to compare the results with levels in AA who have recovered spontaneous menstruation (SM). METHODS: Female athletes (n = 151) were recruited at the Japan Institute of Sports Sciences and the University of Tokyo. All participants were divided into four groups: an AA group (untreated group) (n = 36), a HT group (n = 55), a SM group (n = 21), and an eumenorrheic athletes (EA) group (n = 39). Height, body weight, blood tests, and dual-energy X-ray absorptiometry were measured at baseline and after 12 months. The HT group was treated daily for 12 months with transdermal estrogen therapy. In addition, participants received oral progestin for 7 days once every 3 months. RESULTS: After 12 months, BMD in the AA group was significantly lower than at baseline; however, BMD in the other three groups was significantly higher than at baseline. The ratio of the change in BMD values before and after 12 months was -1.6 ± 3.2% for the AA group, 5.3 ± 8.7% for the HT group, 11.1 ± 8.9% for the SM group, and 2.3 ± 5.7% for the EA group. The rate of change in BMD values in the SM group was greater than that in the HT group. CONCLUSION: HT increased BMD in AA with low BW, and the increase in those with SM was greater than that in those treated with HT.

Sport and exercise genomics: the FIMS 2019 consensus statement update.

Rapid advances in technologies in the field of genomics such as high throughput DNA sequencing, big data processing by machine learning algorithms and gene-editing techniques are expected to make precision medicine and gene-therapy a greater reality. However, this development will raise many important new issues, including ethical, moral, social and privacy issues. The field of exercise genomics has also advanced by incorporating these innovative technologies. There is therefore an urgent need for guiding references for sport and exercise genomics to allow the necessary advancements in this field of sport and exercise medicine, while protecting athletes from any invasion of privacy and misuse of their genomic information. Here, we update a previous consensus and develop a guiding reference for sport and exercise genomics based on a SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis. This SWOT analysis and the developed guiding reference highlight the need for scientists/clinicians to be well-versed in ethics and data protection policy to advance sport and exercise genomics without compromising the privacy of athletes and the efforts of international sports federations. Conducting research based on the present guiding reference will mitigate to a great extent the risks brought about by inappropriate use of genomic information and allow further development of sport and exercise genomics in accordance with best ethical standards and international data protection principles and policies. This guiding reference should regularly be updated on the basis of new information emerging from the area of sport and exercise medicine as well as from the developments and challenges in genomics of health and disease in general in order to best protect the athletes, patients and all other relevant stakeholders.

Low Bone Mineral Density in Elite Female Athletes With a History of Secondary Amenorrhea in Their Teens.

OBJECTIVE: To determine whether secondary amenorrhea during teenage years influences bone mineral density (BMD) in female athletes in their 20s. DESIGN: Original research. SETTING: Japan Institute of Sports Sciences. PARTICIPANTS: Two hundred ten elite female athletes older than 20 years were included in the study. MAIN OUTCOME MEASURES: Information on the participants' past (ie, during their teenage years) and current menstrual cycle, training time, history of stress fractures, and blood tests for hormones received was obtained. Bone mineral density of the lumbar spine was evaluated by dual-energy x-ray absorptiometry; low BMD was defined as a Z-score ≤-1. We investigated the correlation factors for low BMD in athletes in their 20s by univariable and multivariable logistic regression analysis. RESULTS: A total of 39 (18.6%) female athletes had low BMD. Secondary amenorrhea in their teens [odds ratio (OR), 7.11, 95% confidence interval (CI), 2.38-21.24; P < 0.001] and present body mass index (BMI) (OR, 0.56, 95% CI, 0.42-0.73; P < 0.001) were independent correlation factors for low BMD in the multivariable logistic regression analysis. The average Z-score for those with secondary amenorrhea in their teens and 20s, secondary amenorrhea in their 20s only, and regular menstruation was -1.56 ± 1.00, -0.45 ± 1.21, and 0.82 ± 1.11 g/cm, respectively. CONCLUSIONS: Secondary amenorrhea for at least 1 year during teenage years in female athletes and BMI at present was strongly associated with low BMD in their 20s.

Relationship between tartrate-resistant acid phosphatase 5b and stress fractures in female athletes.

BACKGROUND: Approximately 10% of female athletes have a history of stress fractures, which most commonly occur between the ages of 16 and 17 years old. PURPOSE: We investigated whether tartrate-resistant acid phosphatase 5b (TRACP-5b), which is a bone resorption marker, can serve as a valid predictor of stress fractures in female athletes in their teens and 20s. METHODS: Three hundred and sixteen elite female athletes were recruited between 2013 and 2015. Serum TRACP-5b and various hormones were examined in blood samples. The serum TRACP-5b level was compared between athletes with and without stress fractures within 3 months after the initial collection of their blood samples. RESULTS: The 316 athletes were divided into two age groups: 13-19 years old and 20-29 years old. Thirty-six athletes (11.4%) experienced new stress fractures within 3 months after the initial collection of their blood samples. The median serum TRACP-5b level was significantly higher in teenage athletes with new stress fractures than in teenage athletes without new stress fractures. In univariate logistic regression analysis, the Z-score of serum TRACP-5b was a significant predictive factor of stress fractures in teenage athletes only (odds ratio: 1.87; 95% CI: 1.31-2.66; P < 0.0012). CONCLUSION: For teenage female athletes, TRACP-5b is a predictor of the risk of stress fractures, and measuring TRACP-5b levels may be useful to prevent stress fractures.

Intervention for Reducing Sleep Disturbances After a 12-Time Zone Transition.

Hoshikawa, M, Uchida, S, and Dohi, M. Intervention for reducing sleep disturbances after a 12-time zone transition. J Strength Cond Res 34(7): 1803-1807, 2020-The purpose of this study was to examine the effect of an intervention consisting of bright light exposure, sleep schedule shifts, and ramelteon on sleep disturbances after a transition of 12 time zones. Two groups, which flew from Tokyo to Rio, participated in this study. The experimental group received the treatment, whereas the control group did not receive any treatment. The experimental group members were exposed to bright light at night and their sleep-wake schedules were gradually delayed for 4 days before their flight. They also took 8 mg of ramelteon once a day for 5 days from the day of their first flight. Both groups departed Tokyo at 14:05, transiting through Frankfurt and arriving in Rio at 05:05. In Rio, it was recommended that they go to bed earlier than usual if they experienced sleepiness. Nocturnal sleep variables measured by wristwatch actigraphy and subjective morning tiredness were compared between groups. Statistical analysis revealed shorter sleep onset latencies (SOLs) in the experimental group (p < 0.01). The SOLs in Rio were 7.7 ± 2.5 minutes for the experimental group and 16.3 ± 3.7 minutes for the control group (d = 0.89, effect size: large). Sleep efficiency for the first 3 nights in Rio was 88.5 ± 1.2% for the experimental group and 82.9 ± 3.0% for the control group (p < 0.01, d = 1.09, effect size: large). These results suggest that the intervention reduced sleep disturbances in Rio. Our intervention may increase the options for conditioning methods for athletic events requiring time zone transitions.

Risk factors of stress fractures due to the female athlete triad: Differences in teens and twenties.

BACKGROUND: The female athlete triad (Triad), defined by the American College of Sports Medicine as low energy availability (LEA) with or without disordered eating, menstrual dysfunction, and low bone mineral density (BMD), is associated with stress fractures and athletes aged 16-17 years are most susceptible. PURPOSE: To examine whether the Triad increases the risk of stress fractures, athletes were assigned to a "teenage" group and a "20s" group. METHODS: This prospective study enrolled 390 elite female athletes and was conducted from 2012 to 2016 at Japan Institute of Sports Sciences. Blood concentrations of various hormones were examined, and BMD was measured at the lumbar spine and throughout the whole body using dual-energy X-ray absorptiometry. LEA was defined as body weight ≤85% of the ideal body weight for teenage athletes, or BMI ≤17.5 for athletes in their 20s. Low BMD was defined as a BMD Z-score of <-1.0 in the lumbar spine and the whole body. RESULTS: Among 390 athletes enrolled, 36 developed new stress fractures within 3 months of registration. The risk for stress fractures due to the Triad in teenage athletes was higher than for athletes in their 20s. In teenage female athletes, secondary amenorrhea, low BMD for the whole body, and a low ratio of actual body weight to ideal body weight increased the risk for stress fractures by 12.9 times, 4.5 times, and 1.1 times, respectively. CONCLUSION: To prevent stress fractures in female athletes with the Triad, age of athletes should be taken into consideration.

Serum Brain-derived Neurotrophic Factor Levels Mirror Bone Mineral Density in Amenorrheic and Eumenorrheic Athletes.

Amenorrhea and osteoporosis are strongly associated in female athletes. Amenorrheic women show lower serum levels of brain-derived neurotrophic factor (BDNF) than eumenorrheic women. BDNF is known to regulate bone tissue development and remodeling; thus, athletes with low serum BDNF levels may show low bone mass. This study investigated the associations between serum BDNF, estradiol, and bone mineral density (BMD) in female athletes. This study included 160 elite female athletes (21.7±4.3 years). Serum levels of BDNF and estradiol were in 195 blood samples obtained from 132 eumenorrheic athletes (EA) and 63 amenorrheic athletes (AA). BMD was measured in the radius, lumbar spine, pelvis, and legs using dual-energy X-ray absorptiometry. AA showed significantly lower serum BDNF levels than EA (p=0.017). Serum BDNF levels were positively and significantly associated with both serum estradiol levels (p=0.0004) and the BMD measured at all sites (all p<0.05). 10 AA received transdermal estrogen therapy, and serum BDNF levels were measured at baseline and 6 months after therapy. Hormone-treated AA demonstrated a significant increase in serum BDNF levels after 6 months (p=0.022). Thus, serum BDNF levels may be associated with decreased BMD and serve as an indicator of the therapeutic effect of estradiol supplementation in female athletes with osteoporosis.

Effects of evening partial body cryostimulation on the skin and core temperatures.

Cryostimulation is widely used to treat inflammation, rheumatism, acute soft tissue injuries, and neurodegeneration. It helps prevent injury and promotes recovery. This study aimed to examine the duration of the effects of evening partial body cryostimulation (PBC) on core and skin temperatures. Seven male athletes participated in this study. On the day of PBC, at 18:00, each athlete was exposed to PBC (approx. -180 °C) in a specially designed cabin for 3 min. On the control day, at 18:00, the participants sat still on a sofa for 10 min. On both days, bedtime was at around 23:00. Wrist and abdominal skin temperatures, except during PBC, were recorded with Thermochron thermistors after 17:30. Core temperatures were monitored with an ingestible and telemetric core body temperature sensor and a data recorder. The circadian rhythm of the core temperature was observed on both days. The core temperature at 22:30 was found to be lower on the PBC day. Wrist and abdominal skin temperatures recovered after PBC; however, the residual effects on both were different. The abdominal skin temperature at 22:30 was lower on the PBC day. Subjective sleep quality and next morning sleepiness did not differ between the conditions. These results suggested that the effects of a 3-min evening PBC session on the core and skin temperatures lasted for several hours. However, these differences did not affect the subjective sleep quality.

Oral contraceptive therapy reduces serum relaxin-2 in elite female athletes.

AIM: Recent investigations have demonstrated that athletes with high relaxin-2 levels have a high risk of anterior cruciate ligament injuries, while athletes taking oral contraceptives (OC) have low relaxin-2 levels. It has not yet been clarified whether taking OC reduces relaxin-2 levels. The purpose of this study was to investigate changes in relaxin-2 levels in athletes taking OC. METHODS: Levels of relaxin-2, estradiol, progesterone, luteinizing hormone and follicle-stimulating hormone were measured in serum samples (n = 183) from 106 elite female athletes. Five athletes with serum relaxin-2 concentrations > 6 pg/mL during the luteal phase were recruited to assess the effect of OC therapy. RESULTS: Serum relaxin-2 concentrations were significantly higher during the luteal phase (n = 57) than in the follicular phase (n = 72), or in athletes on OC therapy (n = 10) (P < 0.001, P < 0.001 and P < 0.05, respectively). In the luteal phase, 36.8% (21/57) of the athletes had relaxin levels > 6 pg/mL. In 23 athletes, serum relaxin-2 concentrations were measured during both the follicular and luteal phases, revealing that relaxin-2 levels were significantly higher in the luteal phase compared with the follicular phase. In 5 out of 23 athletes, serum relaxin-2 concentrations were > 6 pg/mL in the luteal phase and during the second cycle of OC therapy, relaxin-2 concentrations decreased dramatically to below the detection limit (0.26 pg/mL). CONCLUSIONS: High serum relaxin-2 concentrations were only detected during the luteal phase. In athletes with high relaxin-2 concentrations during the luteal phase, OC therapy decreased serum relaxin-2 levels.

Use of supplements by Japanese elite athletes for the 2012 Olympic Games in London.

OBJECTIVE: To investigate supplement use among Japanese elite athletes. DESIGN: We conducted a cross-sectional survey study using individual interviews during athletes' medical evaluations. SETTING: One to 5 months before the Olympic Games in 2012, London, United Kingdom. PARTICIPANTS: Five hundred fifty-two Japanese athletes for the London Games, including candidates. INDEPENDENT VARIABLES: Sex, sports, supplement category, and participation. MAIN OUTCOME MEASURES: Whether athletes used supplements, what products were used, the frequency and purposes of use, and from what sources athletes received information on supplements. RESULTS: All 552 athletes were interviewed by pharmacists regarding supplement use and agreed to the survey. Of them, 452 (81.9%) used 1 or more supplement products in the year before the study; a total of 952 different products (mean = 1.7, SD = 1.4) were used. The most commonly used supplement was amino acids (310 athletes; 56.2%), and 358 (38.7%) of the total products were amino acids. Of the athletes, 241 (43.7%) took at least 1 supplement daily, and of the supplements, 457 (49.4%) were taken daily. The most common purpose for supplement use was recovery from fatigue-327 (59.2%) athletes chose this answer, and 486 (52.5%) products were used for this purpose. Finally, regarding athletes' information sources on supplements, coaches, managers, and trainers were the most frequent advisors (275 athletes, 49.8%; 466 products, 50.4%). CONCLUSIONS: The results revealed widespread supplement use among Japanese elite athletes for the London Olympic Games. Education system was required not only for athletes but also for athletes' entourage, such as coaches, managers, trainers, and supplement companies. CLINICAL RELEVANCE: This study will provide basic data for establishing an education system that would better guide athletes' use of supplements.

Measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography.

BACKGROUND: The B-mode ultrasound image that can measure muscle architecture is displayed side by side with the ultrasound strain elastogram that can assess muscle hardness. Consequently, muscle architecture can be measured concurrently with muscle hardness using ultrasound strain elastography. PURPOSE: To demonstrate the measurement of muscle architecture concurrently with muscle hardness using ultrasound strain elastography. MATERIAL AND METHODS: Concurrent measurements of muscle architectural parameters (muscle thickness, pennation angle, and fascicle length) and muscle hardness of the medial gastrocnemius were performed with ultrasound strain elastography. Separate measurements of the muscle architectural parameters were also performed for use as reference values for the concurrent measurements. Both types of measurements were performed twice at 20° dorsiflexion, neutral position, and 30° plantar flexion. RESULTS: Coefficients of variance of the muscle architectural parameters obtained from the concurrent measurements (≤7.6%) were significantly higher than those obtained from the separate measurements (≤2.4%) (all P < 0.05). Intraclass correlation coefficients of the architectural parameters were lower in the concurrent measurements (≥0.74) than in the separate measurements (≥0.97). However, there were no significant differences in any muscle architectural parameters between the concurrent and separate measurements (all P > 0.05). CONCLUSION: The use of ultrasound strain elastography for the concurrent measurement of muscle architecture and muscle hardness is feasible.

Magnetic resonance imaging findings related to sacroiliac joint pain in high-performance athletes.

BACKGROUND: Sacroiliac joint (SIJ) dysfunction in athletes affects competitiveness. However, the pathology and imaging features have not been clarified. OBJECTIVE: To clarify the association between SIJ pain and MRI findings in high-performance athletes. METHODS: Fifty-two Japanese high-performance athletes with or without SIJ pain were recruited. MRI short tau inversion recovery (STIR) semi-coronal and semi-axial images of their SIJs were taken. The relationships between high-signal changes in MRI-STIR and SIJ pain and pain duration were investigated. Six athletes with continuous SIJ pain were prospectively followed. RESULTS: The proportion of athletes with high-signal changes in the SIJ was significantly higher among athletes with SIJ pain for one month or more (76.9%, 10/13) than among athletes with SIJ pain for less than one month (18.2%, 2/11) and among athletes without SIJ pain (28.6%, 8/28). High-signal changes on painful SIJs were most often present in the sacrum. In three of the six athletes who were prospectively followed, the high-signal area and intensity on MRI both diminished as their symptoms improved. CONCLUSIONS: High-signal changes of the SIJ on MRI-STIR images in high-performance athletes may reflect their SIJ pain.

Relationships between muscle size and hardness of the medial gastrocnemius at different ankle joint angles in young men.

BACKGROUND: Measurement of muscle hardness is important for objective evaluation of the muscle condition. Muscle hardness may be related to muscle size, but this relationship has not yet been examined. PURPOSE: To examine the relationship between the size and hardness of the medial gastrocnemius muscle (MG) at different ankle joint angles. MATERIAL AND METHODS: Twelve young male subjects comprised the present study. Muscle thickness of the right MG (MT(MG)) was measured by ultrasonography as an index of muscle size. The MT(MG) was determined at 30% of the lower leg length from the popliteal crease to the lateral malleolus. At the same site, muscle hardness of the right MG (MH(MG)) was measured with ultrasound real-time tissue elastography. Both measurements were taken while each subject was instructed to lie in a prone position on a test bench. The right ankle was secured to a handmade apparatus by a non-elastic belt, with the hip and knee joints fully extended and the ankle positioned at +30°, 0° and -20° (0°: neutral position, positive values indicating plantar flexion). RESULTS: There were no significant differences in the MT(MG) among the ankle joint angles whereas the MH(MG) significantly increased as the ankle was moved from plantar flexion to dorsiflexion. As a result, there was a difference in the MT(MG)-MH(MG) relationship between the angles. The MT(MG) significantly correlated with the MH(MG) only at +30° (r = 0.635, P < 0.05) where passive torque around the ankle has been shown to be near zero in previous studies. CONCLUSION: The hardness of the relaxed MG with no passive tension appears to depend on its size.

Use of supplements by young elite Japanese athletes participating in the 2010 youth Olympic games in Singapore.

OBJECTIVE: To investigate the prevalence of supplement use among young elite Japanese athletes. DESIGN: Survey study. SETTING: 2010 Youth Olympic Games, Singapore. PARTICIPANTS: Data were collected from individual interviews during medical evaluations of 75 athletes selected for the Japanese national team. MAIN OUTCOME MEASURES: Main outcome measures included the use of supplements, products used, frequency of use, purpose of use, and relationships between supplement use and athlete attitudes toward a balanced diet. RESULTS: All 75 athletes agreed to participate in this study, and individual interviews by pharmacists made it possible to collect complete answers from all athletes. Of these athletes, 47 (62.7%) used 1 or more supplement products (average number of products used, 1.1 ± 1.3). The most popular supplement was amino acids, which were used by 33 athletes (44.0%). Of the supplements used, 28 (32.6%) were taken every day, whereas 28 (32.6%) were used only on special occasions. Moreover, 34 of the supplement products (39.5%) were taken to enhance recovery from fatigue, whereas 19 (22.1%) were used to improve athletic performance. Statistical analysis suggested that there was no significant relationship between supplement use and attitudes toward a balanced diet. CONCLUSIONS: The results revealed widespread supplement use among young elite athletes in the Japanese national team for the Singapore Youth Olympic Games in 2010. Moreover, these athletes apparently used supplements without considering the effects of their normal diets.

Joint position statement of the International Federation of Sports Medicine (FIMS) and European Federation of Sports Medicine Associations (EFSMA) on the IOC framework on fairness, inclusion and non-discrimination based on gender identity and sex variations.

The IOC recently published its framework on fairness, inclusion and non-discrimination based on gender identity and sex variations. This framework is drafted mainly from a human rights perspective, with less consideration for medical/scientific issues. The framework places the onus for gender eligibility and classification entirely on the International Federations (IFs), even though most will not have the capacity to implement the framework. The position of no presumption of advantage is contrary to the 2015 IOC consensus. Implementation of the 2021 framework will be a major challenge for IFs that have already recognised the inclusion of trans and women athletes with differences of sexual development (DSD) using a scientific/medical solution. The potential consequences for sports that need to prioritise fairness or safety could be one of two extremes (1) exclusion of all transgender or DSD athletes on the grounds of advantage or (2) self-identification that essentially equates to no eligibility rules. Exclusion of all transgender or DSD athletes is contrary to the Olympic charter and unlawful in many countries. While having no gender eligibility rules, sport loses its meaning and near-universal support. Athletes should not be under pressure to undergo medical procedures or treatment to meet eligibility criteria. However, if an athlete is fully informed and consents, then it is their free choice to undergo carefully considered or necessary interventions for gender classification for sport to compete fairly and safely in their chosen gender. Free choice is a fundamental human right, but so is the right to fair and safe competition.

The Effects of the COVID-19 Environments on Changes in Body Composition in Japanese Elite Fencing Athlete.

The Japanese government declared a state of emergency from 7 April to 25 May to limit people's movement due to the coronavirus disease (COVID-19) pandemic. This pandemic negatively affects athletes' body composition due to inactivity. Therefore, we compared the body composition data (i.e., fat-free mass (FFM) and fat mass (FM)), of 43 Japanese elite fencers (22 men, 21 women), in September 2019 for baseline, and of 21 (12 men, 9 women) who completed the following measurements in June 2020 (POST; immediately after rescinding the emergency state) and September 2020 (POST-4M; 4-months after rescinding the emergency state). Results at baseline indicate no significant differences in body compositions among fencing disciplines. We also confirmed no significant changes in body mass during the 1-year investigation period in either sex. There were no time-course changes in men's FFM and FM; however, time-course changes in women's FM were observed. Compared to the baseline, FM values were significantly higher at POST and then returned to baseline levels at POST-4M in women. In conclusion, the 2-month stay-at-home period due to COVID-19 negatively affected women's FM changes, but not their FFM or men's FM.