PURPOSE: Female athletes often face challenges in returning to exercise training programs after pregnancy and parturition. This study aimed to conduct a meta-analysis to investigate the optimal duration for elite female athletes to resume their pre-pregnancy training programs.METHODS: Nine studies were included in this meta-analysis with a total of 1,466 women, comprising 567 nonathletes and 899 athletes. The effect sizes were calculated as differences in health-related indicators, athletic performance, and training volume during five periods: early, mid, and late pregnancy; within 6 months postpartum; and between 7 and 12 months postpartum, compared with prepregnancy levels.RESULTS: Female athletes included in the study did not return to their pre-pregnancy physical condition even one year postpartum. Health indicators decreased substantially during pregnancy and remained lower than pre-pregnancy levels for up to one year postpartum. During pregnancy, there was a considerable reduction in training volume, which persisted throughout one year postpartum. However, athletic performance within the first year postpartum was not significantly different from pre-pregnancy levels; this finding is based on a single study, indicating a limitation due to the insufficient number of studies included in the analysis.CONCLUSIONS: This study demonstrated that female athletes did not fully recover their physical condition or function within one year postpartum. Nevertheless, this finding does not imply that female athletes are unprepared or unable to resume exercise training within one year postpartum. Sufficient return to training can be achieved within this timeframe, but it is crucial to progressively and safely increase training volume and intensity in accordance with individual physiological recoveries.

PURPOSE: Hypoxic training enhances oxygen availability by elevating hemoglobin, red blood cells, and capillaries. hypoxia-inducible factor (HIF) stabilization under hypoxic conditions triggers glycolysis, erythropoiesis, and angiogenesis. However, prolonged hypoxic exposure causes endothelial cell dysfunction, contributing to cardiovascular diseases. Furthermore, endothelial mitochondria play a crucial role in maintaining endothelial cell homeostasis through the processes of biogenesis, signaling cellular response, mitochondrial dynamics, and calcium homeostasis. However, the molecular response of endothelial mitochondria has not been fully elucidated. Therefore, this study aimed to investigate the endothelial mitochondria functions and morphological change in response to hypoxia.METHODS: Cobalt chloride and 2% hypoxic condition were applied to HUVECs. The endothelial cell functions were assessed using BrdU-based proliferation assay and scratch wound healing assays. Mitochondrial functions were evaluated using Mitosox and MitoTracker staining for mitochondrial reactive oxygen species (mtROS) and mitochondrial morphology analysis, respectively.RESULTS: The hypoxic condition (2% of O2) significantly decreased endothelial proliferation/migration and mitochondrial function. Furthermore, CoCl2 treatment increased the mtROS levels and mitochondrial fragmentation in HUVECs. Additionally, hypoxic conditions were found to regulate the phosphorylation of eNOS, mitochondrial biogenesis, mitophagy, and cell cycle-related protein expression.CONCLUSIONS: These results suggest that the HIF-α pathway leads to endothelial dysfunction via mitochondrial dysfunction. Further mechanistic studies will be needed to elucidate the cellular and molecular mechanisms by which hypoxic-response pathways influence the health and homeostasis of endothelial cells. The findings reported herein underscore the importance of strategies for hypoxic training to prevent cardiovascular diseases.

PURPOSE: This study evaluates the suitability of the Exerheart exergame as an alternative tool to moderate-intensity aerobic exercise for healthy adults.METHODS: A total of 49 healthy adults were enrolled in the study. For the first visit (visit 1), all participants underwent a cardiopulmonary exercise test (CPX) on a treadmill to assess maximum oxygen consumption (VO2max). For the second visit (visit 2), the oxygen consumption (VO2peak and VO2mean) was measured during the performance of Exerheart, three times for 10 minutes each to determine its exercise intensity.RESULTS: VO2max during the CPX was 30 ± 8.1 mL/kg/min, while VO2peak during Exerheart was 17.4 ± 3.4 mL/kg/min and VO2mean was 16.3 ± 3.3. The Exerheart intensity generated a VO2peak of 60.4 ± 16.3% and VO2mean of 56.0 ± 15.7 of the VO2max as achieved during the CPX. No significant differences were observed by age group for VO2peak/VO2max or VO2mean/VO2max.CONCLUSIONS: Exerheart exergame corresponds to moderate-intensity aerobic exercise range according to ACSM guidelines. Therefore, Exerheart exergame may be used as an effective alternative to aerobic exercise intervention for healthy adults.

PURPOSE: In this study, the isokinetic strength of ankle inversion and eversion in Korean professional basketball players (KBL) was assessed, distinguishing between their dominant and non-dominant legs, as well as across different positions.METHODS: A meticulously designed study was conducted involving 25 KBL players (12 guards, 11 forwards, and 2 centers) with an average age of 27.8 ± 5.3 years. The CSMI Norm isokinetic dynamometer, a highly accurate instrument, was used to measure bilateral isokinetic concentric strength at 60°·s-¹ and 150°·s-¹. The study measured peak torque (Nm), body mass normalized peak torque (Nm·kg-¹), bilateral strength asymmetry, and the eversion-to-inversion strength ratio in both dominant and non-dominant legs.RESULTS: Peak torques, normalized peak torques, and eversion-to-inversion strength ratios were not significantly different between the dominant and non-dominant legs at the two angular speeds. There was also less than a 10% asymmetry in strength between the two legs. However, a position-specific analysis revealed that guards had a significantly higher normalized peak torque (0.35 vs. 0.30 Nm·kg-1, p = .048) for ankle inversion of the dominant leg at 150°·s-¹ compared to forwards.CONCLUSIONS: The results suggest that healthy KBL players exhibit symmetrical ankle inversion and eversion muscle strength between their dominant and non-dominant sides, with possible positional differences in strength. These findings serve as a reference for the assessment of inversion and eversion strength in basketball players.

Skeletal muscles are composed of several fiber types that differ in their structure, molecular composition, metabolic activity, and functional properties. The four major myosin heavy chain (MyHC) isoforms, slowtwitch oxidative (type I), fast-twitch oxidative (type IIa), fast-twitch oxidative glycolytic (type IId/x), and fast-twitch glycolytic (type IIb), are heterogeneously distributed in the skeletal muscles of mammals, and are useful markers for the muscle fiber types [1] . In humans, MyHC IIb is not detectable in skeletal muscles, but MYH4, the gene encoding this protein, is

PURPOSE: Exercise can reduce postprandial hyperglycemia by increasing contraction-mediated glucose uptake in skeletal muscles. However, postprandial exercise does not always have similar effects in all patients. This study aimed to analyze the factors influencing glucose response to exercise following oral glucose load.METHODS: We enrolled 169 adults with impaired glucose tolerance (IGT, n = 64) and type 2 diabetes (T2D, n = 105). We measured fingertip capillary blood glucose level at 30-minute intervals over 2-hour after the 75-g oral glucose ingestion. In addition, a single bout of moderate-intensity aerobic exercise was conducted at 30 minutes after 75-g oral glucose ingestion. We also measured glycated hemoglobin (HbA1c), insulin, insulin resistance (HOMA-IR), β-cell function (HOMA-β), physical activity level questionnaire and anthropometrics.RESULTS: There was a significant difference in glucose concentration between the IGT and T2D groups (<i>p</i> <.001). Additionally, we found that patients with short diabetes duration (≤1 year) had significantly more decrease in glucose concentration than long diabetes duration (≥10 years) (<i>p</i> <.001). A regression analysis showed that waist circumference, visceral fat area, fasting glucose, HbA1c, and HOMA-IR affected glucose response to exercise following oral glucose load in patients with T2D.CONCLUSIONS: Higher volumes of exercise following an oral glucose load may be necessary for individuals with Type 2 Diabetes (T2D) who have a longer disease duration, larger waist circumference, increased visceral fat area, higher HbA1c levels, and elevated HOMA-IR values in order to prevent hyperglycemia.

PURPOSE: The purpose of this study was to investigate the effects of hyperventilation in the presence of fine particulate matter (PM2.5) on inflammatory and apoptotic responses in the lungs of mice during a single bout of aerobic exercise.METHODS: The FVB/N mice were housed in a controlled SPF room and randomly divided into four groups: control (CON, n=7), fine particulate matter exposure (PM, n=7), PM and exercise (PME, n=7), and exercise only (EX, n=7). Acute PM exposure and/or aerobic treadmill exercise were undertaken according to the groups using a specially designed PM treadmill chamber.RESULTS: Protein expression and phosphorylation of p65 NF-kB in mouse lungs were significantly increased by acute exercise, but not by PM exposure. Basal protein levels and phosphorylation of MAPKs (p38, ERK, and JNK) were significantly increased in the PME group, but were lower in the PM and EX groups. Although the percentage of collagen fibers in lung tissue was not affected by PM exposure, the expression of pro- and antiapoptotic factors BAX, BID, and Bcl-2 was significantly elevated by inhalation of PM during exercise.CONCLUSIONS: In this study, the MAPKs family was activated by excessive PM inhalation during exercise and similar changes in apoptosis-related signaling were observed. This suggests that even a single bout of inhalation of fine particulate matter during exercise can affect factors associated with inflammation and cell death.

PURPOSE: Resistance exercise is an effective behavioral intervention for improving skeletal muscle mass and strength, and preventing sarcopenia. However, the effects of resistance exercise on arterial stiffness remain controversial. This study aimed to organize and analyze the effects of resistance training intensity on arterial stiffness in healthy adults without overt clinical disease.METHODS: A thorough literature search was conducted to retrieve original research articles between 2000 and 2023 using the PubMed, Web of Science, and Google Scholar databases.RESULTS: Long-term low-intensity resistance training (RT) was deemed a safe exercise intervention that can maintain or decrease arterial stiffness and increase muscle strength. Moreover, moderate-intensity RT was effective in improving muscle strength and hypertrophy but did not reduce arterial stiffness. High-intensity RT was an excellent intervention for enhancing muscle strength. However, a potential risk of increasing both central and peripheral artery stiffness in young adults was present.CONCLUSIONS: Compared to low-intensity RT, moderate-to-high-intensity RT was more effective in improving muscle strength and hypertrophy, but may increase arterial stiffness.

PURPOSE: This study aimed to investigate whether endurance and resistance training sequences and circadian rhythms affect muscle hypertrophy and mitochondrial biogenesis-related molecules in obese rats.METHODS: Rats were randomly divided into five groups: the obesity control group (OCG), aerobic-resistance exercise in the morning group (ARMG), resistance-aerobic exercise in the morning group (RAMG), aerobic resistance exercise in the evening group (AREG), and resistance-aerobic exercise in the evening group (RAEG). The exercise groups performed endurance and resistance exercises for 8 weeks according to their circadian rhythms and exercise sequences.RESULTS: We evaluated specific muscle hypertrophy and mitochondrial biogenesis markers in the flexor pollicis longus and soleus muscles using western blot and immunofluorescence techniques. The body weight was significantly decreased in the ARMG, RAMG, AREG, RAEG compared to the OCG after intervention. The soleus muscle fiber cross-sectional area and muscle hypertrophy markers p-Akt and p-mTOR were significantly increased in the AREG group compared with those in the OCG, ARMG, RAMG, and RAEG groups after exercise intervention. Most mitochondrial biogenesis-related markers were significantly increased in the RAMG group than in the other groups after exercise intervention.CONCLUSION: Our findings provide new evidence that muscle hypertrophy might be upregulated by resistance exercise after evening endurance exercise. In addition, morning resistance exercise followed by aerobic exercise, might promote mitochondrial biogenesis.