As an invisible “endocrine organ”, gut microbiota is widely involved in the regulation of nervous system, endocrine system, circulatory system, and digestive system. It is also closely related to host health and the occurrence of many chronic diseases. Relevant literature shows that high temperature, low temperature, and high-altitude hypoxia may have negative effects on commensal microorganisms. The stimulation of exercise may aggravate this reaction, which is related to the occurrence of exercise-induced fever and gastrointestinal and respiratory diseases. The intervention of probiotics can alleviate the above problems to a certain extent. Therefore, this paper takes exercise in a special environment as the starting point, deeply analyses the intervention effect and potential mechanism of probiotics, and provides the theoretical basis and reference for follow-up research and application of probiotics in sports science.
eywords Probiotics; Exercise; High-/low-temperature environment; High-altitude hypoxia; Gut microbiota
Several targeted upper extremity injury prevention programs have been developed to mitigate the risk of upper extremity overuse injuries among youth athletes in overhead sports; however, their effectiveness on performance outcome measures has not been investigated. This systematic review evaluated the effectiveness of existing upper extremity injury prevention programs that focused on modifying intrinsic risk factors, and performance outcome measures in overhead youth athletes. The secondary aim was to identify the training components of these programs. PubMed, Physiotherapy Evidence Database (PEDro), SPORTDiscus (via EBSCOhost), and Web of Science were searched from January 2000 to November 2020 for studies that implemented training programs or exercises for upper extremity injury prevention among youth athletes in overhead throwing or striking sports. An updated search was conducted from December 2020 to October 2022. A program was deemed effective for a performance outcome measure if significant improvements were observed in the intervention group as compared to the control group. Of the 1 394 studies identified, five studies met the inclusion criteria. The effectiveness of the injury prevention programs on the identified performance outcome measures of strength, mobility, and sport-specific measures were 30.4%, 28.6%, and 22.2%, respectively. The training components targeted were strength, mobility, and plyometrics. Strength was the most common training component and was also the most widely investigated performance outcome measure. Overall, current upper extremity injury prevention programs seem effective at improving performance outcome measures of strength, mobility, and sport-specific outcomes with training components of strength, mobility and plyometrics. Standardized protocols are required for the measurement and reporting of performance outcomes measures, and the reporting of training components.
It is unknown whether oxygen uptake (V̇O2) sampling intervals influence the efficacy of a verification stage following a graded exercise test (GXT). Fifteen females and 14 males (18-25 years) completed a maximal treadmill GXT. After a 5 min recovery, the verification stage began at the speed and grade corresponding with the penultimate stage from the GXT. Maximal oxygen consumption (V̇O2max) from the incremental GXT (iV̇O2max) and V̇O2max from the verification stage (verV̇O2max) were determined using 10 seconds (s), 30 s, and 60 s from breath × breath averages. There was no main effect for V̇O2max measure (iV̇O2maxvs. verV̇O2max) 10 s ([47.9 ± 8.31] ml∙kg−1∙min−1 vs [48.85 ± 7.97] ml∙kg−1∙min−1), 30 s ([46.94 ± 8.62] ml∙kg−1∙min−1 vs [47.28 ± 7.97] ml∙kg−1∙min−1), and 60 s ([46.17 ± 8.62] ml∙kg−1∙min−1 vs [46.00 ± 8.00] ml∙kg−1∙min−1]. There was a stage × sampling interval interaction as the difference between (verV̇O2max−iV̇O2max) was greater for 10-s than 60-s sampling intervals. The verV̇O2max was > 4% higher than iV̇O2maxin 31%, 31%, and 17% of the tests for the 10-s, 30-s, and 60-s sampling intervals respectively. Sensitivity for the plateau was < 30% for 10-s, 30-s, and 60-s sampling intervals. Specificity ranged from 44% to 60% for all sampling intervals. Sensitivity for heart rate + respiratory exchange ratio was > 90% for all sampling intervals; while specificity was < 25%. Findings from the present study suggest that the efficacy of verification stages for eliciting a higher V̇O2max may be influenced by the sampling interval utilized.
Coronavirus Disease 2019 (COVID-19) has significantly affected different physiological systems, with a potentially profound effect on athletic performance. However, to date, such an effect has been neither addressed nor investigated. Therefore, the aim of this study was to investigate fitness indicators, along with the respiratory and metabolic profile, in post-COVID-19 athletes. Forty male soccer players, were divided into two groups: non-hospitalized COVID-19 (n = 20, Age: [25.2 ± 4.1] years, Body Surface Area [BSA]: [1.9 ± 0.2] m2, body fat: 11.8% ± 3.4%) versus [vs] healthy (n = 20, Age: [25.1 ± 4.4] years, BSA: [2.0 ± 0.3] m2, body fat: 10.8% ± 4.5%). For each athlete, prior to cardiopulmonary exercise testing (CPET), body composition, spirometry, and lactate blood levels, were recorded. Differences between groups were assessed with the independent samples t-test (p < 0.05). Several differences were detected between the two groups: ventilation (V˙E: Resting: [14.7 ± 3.1] L·min−1 vs. [11.5 ± 2.6] L·min−1, p = 0.001; Maximal Effort: [137.1 ± 15.5] L·min−1 vs. [109.1 ± 18.4] L·min−1, p < 0.001), ratio VE/maximal voluntary ventilation (Resting: 7.9% ± 1.8% vs. 5.7% ± 1.7%, p < 0.001; Maximal Effort: 73.7% ± 10.8% vs. 63.1% ± 9.0%, p = 0.002), ratioVE/BSA (Resting: 7.9% ± 2.0% vs. 5.9% ± 1.4%, p = 0.001; Maximal Effort: 73.7% ± 11.1% vs. 66.2% ± 9.2%, p = 0.026), heart rate (Maximal Effort: [191.6 ± 7.8] bpm vs. [196.6 ± 8.6] bpm, p = 0.041), and lactate acid (Resting: [1.8 ± 0.8] mmol·L-1 vs. [0.9 ± 0.1] mmol·L-1, p < 0.001; Maximal Effort: [11.0 ± 1.6] mmol·L-1 vs. [9.8 ± 1.2] mmol·L-1, p = 0.009), during CPET. No significant differences were identified regarding maximal oxygen uptake ([55.7 ± 4.4] ml·min−1·kg−1 vs. [55.4 ± 4.6] ml·min−1·kg−1, p = 0.831). Our findings demonstrate a pattern of compromised respiratory function in post-COVID-19 athletes characterized by increased respiratory work at both rest and maximum effort as well as hyperventilation during exercise, which may explain the reported increased metabolic needs.
Nonalcoholic fatty liver disease (NAFLD) is a prevalent medical condition with an ever-growing trend. Although multiple intracellular mechanisms are involved, endoplasmic reticulum (ER) stress has been demonstrated to play a significant role in the genesis and progression. Most of the research supports the advantages of exercise for NAFLD. However, little is known about the molecular mechanism(s) that underpin the effectiveness of exercise training in NAFLD. This study aimed to identify how aerobic exercise affected hepatic ER stress in a mouse NAFLD model. In this study, the mice were fed either a standard diet (SD) or a high-fat diet (HFD) for 17 weeks. HFD mice were trained on a treadmill during the last eight weeks. All animals were tested for serum levels of biochemical assays, protein expression, and gene expression. The hematoxylin and eosin, Oil red O, and immunohistochemistry staining were also performed. The results indicated that a high-fat diet generated NAFLD, with serum lipid disruption and hepatic function impairment, and increased GRP78 and ATF6 expressions. However, aerobic training reversed the majority of these alterations. It is concluded that NAFLD appears to be associated with hepatic ER stress response, and aerobic exercise mitigates NAFLD via lowering ER stress proteins GRP78 and ATF6.
At the altitude, hypoxia and training load are key factors in the development of oxidative stress. Altitude-induced oxidative stress is developed due to the depletion of antioxidant potential. In the current study, we examined the non-enzymatic antioxidant profile of blood plasma in 7 males and 5 females specializing in speed skating at a 21-day training camp at 1 850 m above sea level. Training included: cycling, roller skating, ice skating, strength training, and special training. At the start point and the endpoint, total hemoglobin mass (tHb-mass), hemoglobin concentration, and circulating blood volume were determined. Antioxidant profiles, hypoxic doses, hypoxic impulses, and training impulses were assessed at 3, 6, 10, 14, and 18 days. Antioxidant profiles consisting of “urate” and “thiol” parts were registered with chemiluminometry. In the training dynamics, antioxidant parameters changed individually, but in total there was a decrease in the “urate” capacity by a factor of 1.6 (p = 0.001) and an increase in the “thiol” capacity by a factor of 1.8 (p = 0.013). The changes in “urate” capacity positively correlated (rS = 0.40) and the changes in “thiol” capacity negatively correlated (rS = −0.45) with changes in tHb-mass. Both exercise and hypoxic factors affect the antioxidant parameters bidirectionally. They correlated with a decrease in thiol capacity and with an increase in urate capacity. The assessment of the non-enzymatic antioxidant profile can be a simple and useful addition to screening the reactive oxygen species homeostasis and can help choose the personalized training schedule, individualize recovery and ergogenic support.
This study aimed to evaluate the efficacy of an individualized remote exercise program on the improvement of body composition and physical fitness of a heterogeneous group of patients who completed breast cancer treatment. This prospective study included 107 women aged 18 to 60, shortly after curative treatment for localized breast cancer, at the Erasto Gaertner Cancer Hospital (HEG) in Curitiba, PR, Brazil. Body composition, maximal oxygen consumption, and muscle resistance were evaluated after nine months of intervention while considering adherence to the program, level of physical activity, presence of binge eating disorder, tumor classification, and treatment type. Seventy-eight women (72.8%) adhered to the training program. Adherent participants showed significant changes in body mass ([-4.3 ± 3.6] kg; p < 0.000 1), body mass index ([-1.6 ± 1.5] kg·m−2; p < 0.000 1), body fat (−3.4% ± 3.1%; p < 0.000 1), maximal oxygen consumption ([7.5 ± 2.0] ml·kg−1·min−1); p < 0.000 1), and abdominal resistance ([11.2 ± 2.8] reps; p < 0.000 1). In contrast, these variables did not change significantly in the non-adherent group. Among the adherent participants, those subclassified in the severe binge group showed a more noticeable reduction in body mass, body mass index, and body fat (p < 0.05) than those in the non-binge group. Individualized remotely-guided physical exercise programs can improve the body composition and physical fitness of women undergoing post-breast cancer surveillance, regardless of pathological history or treatment.
High intensity interval training (HIIT) causes oxidative stress and haematological alteration. Present study was aimed to evaluate the effect of 8 weeks’ supplementation of vitamin C and E on HIIT induced changes in lipid profile parameters and haematological variables. Hundred six male adolescent players were randomly assigned into five age-matched groups, i.e., Control (no exercise+placebo), HIIT (placebo), HIIT + vitamin-C (1 000 mg/day), HIIT + vitamin-E 400 IU/day) and combined HIIT + vitamin C and E. Morning and evening sessions (90 min) of HIIT included 4 phases (15 min each) with 3 sets (4 min each). Each 4 min HIIT set consisted of 2 min intense sprint workout (90%-95% of heart rate maximum [HRmax]) followed by 1 min active recovery (60%-70% HRmax) followed by 1 min of complete rest (1:1 work-rest ratio). Lipid profile parameters, haematological variables, endurance capacity and vertical jump were evaluated by standard protocols. Significant decrease in body weight, fat%, total cholesterol, triglyceride, Total Cholesterol/High Density Lipoprotein-Cholesterol and significant increase in High Density Lipoprotein-Cholesterol, maximal oxygen consumption, vertical jump were observed for all four intervention groups. White blood cell count, red blood cell count, haemoglobin percentage and haematocrit values were significantly decreased while platelet count and platelet-to-leukocyte ratio (PLR) ratio were increased significantly only for HIIT group. Blood level of tocopherol and ascorbic acid was significantly increased (values were within the normal range) in all the respective vitamin supplemented groups. Supplementation of vitamin C and E secures health protection with suppressed haemolysis and improved inflammatory blood variables with enhanced explosive leg strength and lipid profile parameters without any concomitant change in endurance capacity.
Concurrent exercise and metformin administration may reduce the acute and chronic effects of exercise on glucose metabolism in the patients with type 2 diabetes (T2D). However, several studies suggest that combing metformin and exercise treatment may have neither additive effect nor even cause adverse effects in T2D patients. This case report aimed to highlight the challenges associated with prescribing exercise to type 2 diabetes patients undergoing metformin treatment. A 67-years old woman was followed-up for five months, including assessment of the acute and chronic glucose and lactate metabolism induced by concomitant exercise and metformin. The findings were four-fold: 1) During a high-intensity interval training bout, blood glucose systematically decreased, while blood lactate concentrations fluctuated randomly; 2) Basal blood lactate levels were well above 2 mmol/L on days with medication only; 3) Combined exercise and metformin administration induced additive effects on the normalization of glucose and 4) high levels of physical activity had a positive impact on the continuous glucose fluctuations, while decreased levels of physical activity induced a large fluctuation of glucose due to home confinement of an infectious disease caused by the SARS-CoV-2 virus. Our findings showed that when combined with exercise and metformin treatment for T2D patients, exercise may contribute to improving glycemic control while metformin may elevate lactate levels in the long term. The observed results underline the need to prescribe exercise and monitor lactate levels for reducing possible risks associated with metformin treatment and reinforce the importance of tailoring exercise therapy.
The large-scale disruptions to physical activity during the coronavirus pandemic have been found to be a leading predictor of common mental disorders. In addition, regular physical exercise has been found to alleviate anxiety, sadness and depression during the pandemic. These findings, together with numerous studies published before the pandemic on the effects of physical activity on mental health, should be considered in the provision of mental health care following the pandemic. Cross-sectional research has revealed that all types of exercise and sport are associated with a reduced mental health burden. Therefore, the effectiveness of exercise and sport participation in sustainable mental health care as well as the causal relationship between exercise, psychosocial health and common mental disorders merit further investigation. Physical activity and sport, with their global accessibility, significant and clinically meaningful efficacy as well as virtual absence of adverse effects, offer a promising option for the promotion of mental health, including the prevention and treatment of common mental disorders. Physical exercise and sport are likely to become valuable public mental health resources in the future.
Assessment of maximal fat oxidation rate (MFO) during a submaximal exercise test has been employed by many studies to investigate the differences in metabolic flexibility (MetFlex) across several populations. Nevertheless, many incorrect assumptions and methodological limitations exist in the procedures employed by previous studies, which might lead to misinterpretation of the reported findings. Considering the data retrieved from 19 trained men (Age: [27 ± 4] years; %Body fat: [16.4 ± 4.5]%; maximal oxygen consumption: [55.8 ± 5.3] mL·kg−1·min−1) who performed a graded exercise test over a motor-driven treadmill, this opinion paper shows that MFO alone does not perfectly capture the MetFlex in response to submaximal intensity exercise and recommend a novel index that considers both fat oxidation and energy expenditure modifications for an accurate examination of MetFlex.
Mobility applications are rapidly growing in cities worldwide due to their convenience and low cost. Mobility applications drivers experience vast flexibility in work hours, often work longer than in fixed-hours jobs, and can constantly transport passengers in their vehicles for up to 12 h; after this, they must go offline for eight consecutive hours before driving again. Nonetheless, drivers have found an easy way around this limitation by switching to other apps and continuing driving. This burden of prolonged work can increase sedentary behavior among mobility applications drivers. Sedentary behavior is any waking activity in which the individual expends 1.5 metabolic equivalents (METs) or less while sitting or reclining. This behavior can increase the risk of detrimental effects on health. In this opinion article, we aim to discuss the possible effects of the burden of prolonged work on the sedentary behavior of mobility applications drivers and propose possible strategies to face this concerning situation.