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.
eywords Acidosis; Bicarbonate; Lactate; Nicotinamide adenine dinucleotide; Sirtuins
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.
We hypothesized that slowed oxygen uptake (V˙O2) 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 V˙O2 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 V˙O2 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 V˙O2 (ss V˙O2) ([3.08 ± 0.30] L⋅min−1, respectively), and 30% Wpeak ss V˙O2 (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 V˙O2 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 V˙O2 kinetics and an increasing V˙O2 deficit for higher exercise intensities within the SS domain.
Obesity has a complex multifactorial etiology and is characterized by excessive accumulation of adipose tissue. Visceral adipose tissue has deleterious effects on health because it secretes large amounts of inflammatory cytokines. Nutritional calorie restriction associated with strength training may be useful in managing chronic systemic inflammation. This study aimed to evaluate the acute effect of a single strength-training session on plasma adipokine levels in sedentary, overweight, and obese young men. This study included twelve men (Age: [34.95 ± 9.77] years; Height: [174.16 ± 3.66] centimeter [cm]; Weight: [97.83 ± 12.87] kilogram (kg); body mass index [BMI]: [32.30 ± 4.51] kg/m2), who performed a single strength training session. The strength training protocol consisted of 4 sets of 12 repetitions in the following six exercises, 45° leg press, bench press, leg extension, machine row, leg curl, and shoulder press. Blood samples were collected before, immediately after, and 1-h subsequent after strength training. The plasma levels of resistin and leptin were measured. A significant decrease in resistin levels were found 1 h after the strength training session if compared to levels before the training session (pre-[before] [2 390 ± 1 199] picograms per milliliter [pg/mL] vs post-1 h [1-h subsequent] [1 523 ± 798],6 pg/mL, p = 0.002 8). The plasma leptin levels did not differ at any time point. In conclusion, a very well controlled single session of strength training significantly decreased the plasma levels of resistin without altering the concentration of leptin in overweight and obese individuals. This effect, at least in part, supports the benefits of exercise by reducing the low grade inflammation and insulin resistance in obesity.
Previous studies have shown that Physical Activity (PA) has a positive association with emotional health and intelligence in adolescents but none have focused on the relationship of PA duration and intensity on Emotional Intelligence (EI). The purpose of this study was to cross-sectionally assess the association of PA measures on overall EI and its domains in a cohort of 2 029 adolescents aged 10-13 years of age in the National Longitudinal Survey for Children and Youth (NLSCY) from Canada. Multivariable linear regression analysis of EI was adjusted for age, sex, annual household income, and health status. One-way analysis of variance (ANOVA) was used to relate PA duration measured in minutes, frequency, and intensity categories with continuous GEI scores and also the corresponding scores for domains of GEI. The mean GEI scores were (28.3 ± 6.6) for 0-30 minute (min) PA duration, (30.0 ± 6.5) for 30 to < 60 min, (30.8 ± 6.7) for 60-120 min, and (30.1 ± 6.5) for ≥ 121 min. There was a statistically significant linear trend across PA duration categories, p = 0.000 4. Post-hoc pairwise comparison revealed that compared to the referent category (< 30 min PA category) was statistically significantly lower GEI than each of the other two PA categories (30-59 min; and 60-120 min), both p-values < 0.01. Meeting World Health Organization (WHO) guidelines for duration and vigorous intensity were positively associated with the higher overall EI and its domains except for Stress Management.
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.
This study aimed to investigate the potential cardioprotective effects of moderate and high-intensity aerobic interval training (MIIT and HIIT) preconditioning. The focus was on histological changes, pro-oxidant-antioxidant balance, autophagy initiation, and apoptosis in myocardial tissue incited by isoproterenol-induced pathological cardiac remodeling (ISO-induced PCR). Male Wistar rats were randomly divided into control (n = 6), ISO (n = 8), MIIT (n = 4), HIIT (n = 4), MIIT + ISO (n = 8), and HIIT + ISO (n = 8) groups. The MIIT and HIIT protocols were administered for 10 weeks, followed by the induction of cardiac remodeling using subcutaneous injection of ISO (100 mg/kg for two consecutive days). Alterations in heart rate (HR), mean arterial pressure (MAP), rate pressure product (RPP), myocardial oxygen consumption (MV˙O2), cardiac hypertrophy, histopathological changes, pro-oxidant-antioxidant balance, autophagy biomarkers (Beclin-1, Atg7, p62, LC3 I/II), and apoptotic cell distribution were measured. The findings revealed that the MIIT + ISO and HIIT + ISO groups demonstrated diminished myocardial damage, hemorrhage, immune cell infiltration, edema, necrosis, and apoptosis compared to ISO-induced rats. MIIT and HIIT preconditioning mitigated HR, enhanced MAP, and preserved MV˙O2 and RPP. The pro-oxidant-antioxidant balance was sustained in both MIIT + ISO and HIIT + ISO groups, with MIIT primarily inhibiting pro-apoptotic autophagy progression through maintaining pro-oxidant-antioxidant balance, and HIIT promoting pro-survival autophagy. The results demonstrated the beneficial effects of both MIIT and HIIT as AITs preconditioning in ameliorating ISO-induced PCR by improving exercise capacity, hemodynamic parameters, and histopathological changes. Some of these protective effects can be attributed to the modulation of cardiac apoptosis, autophagy, and oxidative stress.
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.
The study aims to investigate the differences in protein expressions in Xizang's (Tibetan) middle-to-long distance runners after the transition from high altitude to low altitude and reveal the molecular mechanisms underlying their enhanced middle-to-long distance running performance. In the study, eleven subjects were selected from native Tibetan middle-to-long distance runners to participate in an 8-week pre-competition exercise training program consisting of a 6-week training stage in Kangding City at an altitude of 2 560 meters (m) and a subsequent 2-week training stage in Leshan City at an altitude of 360 m. Blood samples were collected twice from the runners before beginning altitude exercise training in Kangding and after going to sea level - Leshan City. Using a label-free quantitative method, peptides in the samples were analyzed by mass spectrometry. Proteomic analysis was performed to identify differentially expressed proteins and predict their biological functions. A total of 846 proteins were identified in the 21 samples, including 719 quantified proteins. In total, 49 significantly differentially expressed proteins (p < 0.05) were identified, including twenty-eight 0.2-fold up-regulated proteins or twenty-one 0.17-fold down-regulated proteins. The up-regulated proteins, including cystic fibrosis transmembrane conductance regulator (CFTR) and carbonic anhydrase I (CAI), were of particular interest due to their role in regulating the oxygen saturation in deep tissues. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that these proteins were mainly involved in regulating actin cytoskeleton, local adhesion, biotin absorption and metabolism, immune system, cancer, and membrane transport processes. In conclusion, Tibetan middle-to-long distance runners who resided in high-altitude areas benefited from repeated plateau-plain alternate training mode during the pre-competition period. The training mode induced positive changes in peripheral blood plasma proteins (CFTR and CAI), the biomarkers associated with aerobic capacity. Among the 11 runners, one female athlete won the gold medal in the 3 000-m running event in this competition, demonstrating that the plateau-plain alternate training mode could enhance the aerobic capacity of athletes.
Wet-cupping therapy (WCT) is one of the oldest known medical techniques, used as a traditional and complementary therapy with a wide application all around the world for general health. Research on the effects of WCT on sports performance are sparse and inconsistent. Thus, we aimed to explore the effects of WCT on repeated sprint ability, wellness, and exertion in young active males. Forty-nine active adult males (age: [28 ± 5] years; body height [177 ± 8] cm; body mass: [79 ± 7] kg; body mass index: [25.4 ± 1.8] kg/m2) were selected for the study. The participants performed a running-based sprint test on two separate occasions (Control and Post-WCT). WCT was performed 24 h before the testing session. They completed the Hooper questionnaire to assess their well-being (i.e., sleep, stress, fatigue, and soreness) before each session. The rating of perceived exertion (RPE) was collected after each testing session. A higher maximum power (p < 0.05, effect size [ES] = 0.6), mean power (p < 0.01, ES = 0.5) and minimum power (p < 0.01, ES = 0.6) were recorded post-WCT as compared to Control session along with a better perceived sleep (p < 0.01, ES = 0.85). Perceived stress (p < 0.01, ES = 0.6) and RPE (p < 0.001; ES = 1.1) were lower during the post-WCT compared to the Control session. The present findings demonstrated that WCT moderately enhanced repeated sprint ability and had positive effects on perceived sleep, stress, and exertion. WCT may be an effective ergogenic aid to improve repeated sprint ability and general well-being in young adult males. Future large-scale multicentric clinical studies are paramount to confirm the results of our study.
Increases in power output and maximal oxygen consumption (V˙O2max) occur in response to sprint interval exercise (SIE), but common use of “all-out” intensities presents a barrier for many adults. Furthermore, lower-body SIE is not feasible for all adults. We compared physiological and perceptual responses to supramaximal, but “non-all-out” SIE between leg and arm cycling exercise. Twenty-four active adults (mean ± SD age: [25 ± 7] y; cycling V˙O2max: [39 ± 7] mL·kg−1·min−1) performed incremental exercise using leg (LCE) and arm cycle ergometry (ACE) to determine V˙O2max and maximal work capacity (Wmax). Subsequently, they performed four 20 s bouts of SIE at 130% Wmax on the LCE or ACE at cadence = 120-130 rev/min, with 2 min recovery between intervals. Gas exchange data, heart rate (HR), blood lactate concentration (BLa), rating of perceived exertion (RPE), and affective valence were acquired. Data showed significantly lower (p < 0.001) absolute mean ([1.24 ± 0.31] L·min−1 vs. [1.59 ± 0.34] L·min−1; d = 1.08) and peak V˙O2 ([1.79 ± 0.48] L·min−1 vs. [2.10 ± 0.44] L·min−1; d = 0.70) with ACE versus LCE. However, ACE elicited significantly higher (p < 0.001) relative mean ([62% ± 9%] V˙O2max vs. [57% ± 7%] V˙O2max, d = 0.63) and peak V˙O2 ([88% ± 10%] V˙O2max vs. [75% ± 10%] V˙O2max, d = 1.33). Post-exercise BLa was significantly higher ([7.0 ± 1.7] mM vs. [5.7 ± 1.5] mM, p = 0.024, d = 0.83) for LCE versus ACE. There was no significant effect of modality on RPE or affective valence (p > 0.42), and lowest affective valence recorded (2.0 ± 1.8) was considered “good to fairly good”. Data show that non “all-out” ACE elicits lower absolute but higher relative HR and V˙O2 compared to LCE. Less aversive perceptual responses could make this non-all-out modality feasible for inactive adults.
Listening to music manipulates attention to be more externally focused, which has the potential to improve muscular efficiency. This study aimed to determine the effect of listening to music on muscle activation during an isometric exercise task, and compare this effect to those of other attentional focus conditions. Apparently healthy subjects (n = 35; 16 men/19 women) completed an isometric elbow flexion task for 1 min in three randomized and counterbalanced conditions: internal focus (INT), external focus with a simple distraction task (EXT), or listening to music (MUS). Muscle activation of the biceps and triceps brachii and heart rate (HR) were recorded throughout the exercise tasks. Ratings of perceived exertion (RPE), affective valence, and motivation were measured at the end of each trial. There was no difference in muscle activation measures among the three conditions. HR during MUS was lower than EXT at 15 s ([89.4 ± 11.8] beats/min vs. [93.1 ± 12.9] beats/min; p = 0.018) and 30 s ([90.6 ± 12.4] beats/min vs. [94.2 ± 12.5] beats/min; p = 0.026), and lower than INT at 60 s ([93.3 ± 13.3] beats/min vs. [96.7 ± 12.0] beats/min; p = 0.016). Overall RPE was higher for INT (13.4 ± 2.2) than for MUS ([12.6 ± 2.0]; p = 0.020) and EXT ([11.94 ± 2.22]; p < 0.001). Affective valence was higher for MUS than for INT ([2.7 ± 1.4] vs. [2.1 ± 1.5]; p = 0.011). Manipulating attentional focus did not alter muscle activation for a light-intensity isometric muscular endurance task, though MUS was reported as more positive and requiring less exertion to complete than INT. Using music can therefore be recommended during light-intensity isometric exercise based on the psychological benefits observed.