Sports Medicine and Health Science最新文献

The purpose of this manuscript was to present the evidence for why cells do not produce metabolic acids. In addition, evidence that opposes common viewpoints and arguments used to support the cellular production of lactic acid (HLa) or liver keto-acids have been provided. Organic chemistry reveals that many molecules involved in cellular energy catabolism contain functional groups classified as acids. The two main acidic functional groups of these molecules susceptible to ∼H⁺ release are the carboxyl and phosphoryl structures, though the biochemistry and organic chemistry of molecules having these structures reveal they are produced in a non-acidic ionic (negatively charged) structure, thereby preventing pH dependent ∼H⁺ release. Added evidence from the industrial production of HLa further reveals that lactate (La⁻) is produced followed by an acidification step that converts La⁻ to HLa due to pH dependent ∼H⁺ association. Interestingly, there is a plentiful list of other molecules that are classified as acids and compared to HLa have similar values for their H⁺ dissociation constant (pK_d). For many metabolic conditions, the cumulative turnover of these molecules is far higher than for La⁻. The collective evidence documents the non-empirical basis for the construct of the cellular production of HLa, or any other metabolic acid.

Physical activity and exercise (PAE) improve quality of life and reduce the effects of chronic diseases. Primary care physicians (PCPs) play an important role to encourage PAE in patients. We aim to assess PCPs' current PAE consultation practices and their enablers/barriers in daily clinical practice. We had 64 PCPs (age [35.3 ​± ​4.7] y, 47 women) that completed self-administered questionnaires on PAE consultation practices, training, and confidence levels. PCPs (n ​= ​42) also completed the International Physical Activity Questionnaire-Short Form to assess their physical activity (PA) levels. We conducted correlation, one-way analysis of variance and a linear regression to assess the associations between enablers, barriers and PA levels to PAE consultation practices. On average, PCPs consulted on PAE in 49.7% of their daily clinical appointments. Majority of PCPs (70%) strongly agreed that more PAE knowledge were needed to increase consultation practices. Top three barriers related (p ​< ​0.001) to practices were lack of PAE education (r ​= ​0.47), patients’ preference of pharmaceutical interventions (r ​= ​0.45) and lack of continuing education in PAE for PCPs (r ​= ​0.37). Physically active PCPs (health-enhancing PA levels, n ​= ​6) gave significantly more daily consultations in PAE, 73.2% ​± ​21.9%, compared to inactive PCPs (n ​= ​13), 37.4% ​± ​22.8% (p ​= ​0.013). In our regression output, PCPs who had higher PA levels consulted more on PAE daily (R² ​= ​0.38, p ​< ​0.001) while controlling for age. Conclusion, PCPs require more knowledge on PAE and need be physically active themselves to increase PAE consultation for patients in their daily practice. Medical education should consider including more PA and exercise topics that may benefit both physicians and their patients.

Healthy movement behaviours are associated with various physical and mental wellbeing; however, little is known about such associations in low- and middle-income countries. The aim of this study was to examine adherence to 24-hour (h) movement guidelines and their relationship with depressive symptoms in adolescents. Data were from 312 Bangladeshi adolescents aged 13–17 years (42% female). Meeting the guidelines was defined as: energy expenditure for physical activity (PA) ​≥ ​1 680 Metabolic Equivalent of Task (MET)-min/week, ≤ 2 ​h/day of recreational screen time (ST), and 8–10 ​h/night of sleep. Depressive symptoms were assessed using the 10-item Center for Epidemiological Studies Depression Scale (CESD-10) with a score of 10 or more indicating high depressive symptoms. Percentage of adolescents meeting the three recommendations was 2.2%, with 17.6% meeting two, and 31.2% meeting one recommendation. Generalized estimating equations showed that odds of having high depressive symptoms was a third (odds ratio [OR] ​= ​0.35, 95% confidence interval [CI], 0.19-0.57) for meeting the PA guidelines, and about a half (OR = 0.47, 95%CI, 0.18-0.87) for meeting the sleep guidelines. Odds of depressive symptoms reduced significantly for meeting PA and sleep (OR = 0.20, 95%CI, 0.09-0.59), or PA and ST (OR ​= ​0.24, 95%CI, 0.08-0.55) guidelines. About half of the adolescents did not meet any recommendations, which underscores the need for public health campaigns to promote adherence to the movement guidelines in this pediatric population. Further longitudinal research with larger sample size is recommended to explore the inter-relationships of these behaviours and their impact on health and wellbeing outcomes of adolescents in Bangladesh.

Pyruvate is a three-carbon ketoacid that occurs naturally in cells. It is produced through enzymatic reactions in the glycolytic pathway and plays a crucial role in energy metabolism. Despite promising early results, later well-controlled studies of physically active people have shown that pyruvate supplementation lasting more than 1 week has no ergogenic effects. However, some data suggest that ingested pyruvate may be preferentially metabolized without accumulation in the bloodstream. Pyruvate exhibits antioxidant activity and can affect the cellular redox state, and exogenous pyruvate can influence metabolism by affecting the acid-base balance of the blood. This brief review focuses on the potential effects of pyruvate as a supplement for active people. The current state of understanding suggests that studies of the effects of pyruvate supplementation should prioritize investigating the timing of pyruvate intake.

Sarcopenia is a progressive systemic skeletal muscle disease induced by various physiological and pathological factors, including aging, malnutrition, denervation, and cardiovascular diseases, manifesting as the decline of skeletal muscle mass and function. Both exercise and nutrition produce beneficial effects on skeletal muscle growth and are viewed as feasible strategies to prevent sarcopenia. Mechanisms involve regulating blood flow, oxidative stress, inflammation, apoptosis, protein synthesis and degradation, and satellite cell activation through exerkines and gut microbiomes. In this review, we summarized and discussed the latest progress and future development of the above mechanisms for providing a theoretical basis and ideas for the prevention and treatment of sarcopenia.

Exercise prescriptions play a vital role in the prevention and treatment of chronic diseases. A consensus regarding exercise prescription is important for physical health. The “Consensus statement of Chinese experts on exercise prescription” (hereinafter referred to as “Expert Consensus”) divides exercise prescription into two categories: fitness exercise prescription and medical exercise prescription. Traditional Chinese fitness exercises, exercise risk, exercise prescription, and basic precautions for exercise prescription are explained.

We hypothesized that slowed oxygen uptake ($\dot{V}{O}_2$) kinetics for exercise transitions to higher power outputs (PO) within the steady state (SS) domain would increase the mean response time (MRT) with increasing exercise intensity during incremental exercise. Fourteen highly trained cyclists (mean ± standard deviation [SD]; age (39 ± 6) years [yr]; and $\dot{V}{O}_2$ peak = (61 ± 9) mL/kg/min performed a maximal, ramp incremental cycling test and on separate days, four 6-min bouts of cycling at 30%, 45%, 65% & 75% of their incremental peak PO (Wpeak). SS trial data were used to calculate the MRT and verified by mono-exponential and linear curve fitting. When the ramp protocol attained the value from SS, the PO, in Watts (W), was converted to time (min) based on the ramp function W to quantify the incremental MRT (iMRT). Slope analyses for the $\dot{V}{O}_2$ responses of the SS versus incremental exercise data below the gas exchange threshold (GET) revealed a significant difference (p = 0.003; [0.437 ± 0.08] vs. [0.382 ± 0.05] L⋅min⁻¹). There was a significant difference between the 45% Wpeak steady state $\dot{V}{O}_2$ (ss $\dot{V}{O}_2$) ([3.08 ± 0.30] L⋅min⁻¹, respectively), and 30% Wpeak ss $\dot{V}{O}_2$ (2.26 ± 0.24) (p < 0.0001; [3.61 ± 0.80] vs. [2.20 ± 0.39] L⋅min⁻¹) and between the iMRT for 45% and 30% Wpeak ss $\dot{V}{O}_2$ values ([50.58 ± 36.85] s vs. [32.20 ± 43.28] s). These data indicate there is no single iMRT, which is consistent with slowed $\dot{V}{O}_2$ kinetics and an increasing $\dot{V}{O}_2$ deficit for higher exercise intensities within the SS domain.

We examined the effects of resistance and aerobic exercise on the gene expression and biometabolic processes of aging skeletal muscle in senescence-accelerated mouse/prone 8 mice, a model of sarcopenia, and compared them with senescence-accelerated mouse/resistant 1 mice acting as controls. We found that exercise improved muscle strength, endurance, fiber size, also modulated genes and pathways related to synaptic transmission, potassium transport, JAK-STAT signaling, and PI3K-Akt signaling. Our results suggested that BDNF, JAK2, RhoC, Myh6, Stat5a, Tnnc1, and other genes may mediate the beneficial effects of exercise on sarcopenia through these pathways.

Outpatients with an acquired brain injury (ABI) experience physical, mental, and social deficits. ABI can be classified into two subgroups based on mechanism of injury: mild traumatic brain injury (mTBI; e.g., concussion) and other ABI (e.g., stroke, brain aneurysm, encephalitis). Our understanding of habitual activity levels within ABI populations is limited because they are often collected using self-report measures. The purpose of this study was to, 1) describe the habitual activity levels of outpatients with ABI using objective and self-report monitoring, and 2) compare the activity levels of outpatients with mTBI vs. other ABI. Sixteen outpatients with other ABI (mean ​± ​standard deviation: [58 ​± ​13] years, 9 females) and 12 outpatients with mTBI ([48 ​± ​11] years, 9 females) wore a thigh-worn activPAL 24 ​h/day (h/day) for 7-days. Outpatients with ABI averaged (6.0 ​± ​2.3) h/day of upright time, (10.6 ​± ​2.2) h/day of sedentary time, (5.6 ​± ​2.7) h/day in prolonged sedentary bouts > 1 ​h, (5 960 ​± ​3 037) steps/day, and (11 ​± ​13) minutes/day (min/day) of moderate-vigorous physical activity (MVPA). There were no differences between activPAL-derived upright, sedentary, prolonged sedentary time, and physical activity between the mTBI and other ABI groups (all, p ​> ​0.31). Outpatients with ABI overestimated their MVPA levels (+138 ​min/week) and underestimated sedentary time (−4.3 ​h/day) compared to self-report (all, p ​< ​0.001). Despite self-reporting high activity levels, outpatients with ABI objectively exhibit highly inactive and sedentary lifestyles. The habitual movement behaviours of our sample did not differ by mechanism of injury (i.e., mTBI versus other ABI). Targeting reductions in objectively measured sedentary time are needed to progressively improve the habitual movement behaviours of outpatients with ABI.