Exercise Performance In Athletes Research Articles

Mapping the citation network on vitamin D research in Australia: a data-driven approach

Vitamin D research can vary geographically, as vitamin D status is influenced by latitude, season, dietary intake, body mass index, ethnicity, and public health initiatives. Over the last two decades, research on vitamin D has increased in Australia, where the potential for sun exposure (a major source of vitamin D) is high. We aimed to identify key topics and gaps in vitamin D research in Australia using a data-driven approach. A literature search limited to Australian studies was conducted in the Web of Science Core Collection database. Citation network analysis was conducted to identify clusters and sub-clusters, depicted using word clouds. Topic analysis of each cluster and sub-cluster was conducted to identify topics and sub-topics, respectively. From 934 publications (over the period 1984–2022), nine topics and 60 sub-topics were identified. The nine topics were: vitamin D in vulnerable populations and its impact on child development; impact of sun exposure and ultraviolet-B radiation on various health conditions; vitamin D and falls and fractures in older adults; vitamin D and its association with health outcomes; vitamin D from sun exposure; testing of vitamin D status in Australia; vitamin D, calcium, and musculoskeletal health; vitamin D status and knee osteoarthritis; and vitamin D status and exercise performance in athletes. There were limited publications on vitamin D in Aboriginal and Torres Strait Islander peoples and dietary vitamin D. We have provided an overview of vitamin D research in Australia. The research trends and knowledge gaps identified can guide future research to better inform public health initiatives in Australia.

Hematological, skeletal muscle fiber and exercise performance adaptations to heat training in elite female and male cyclists.

Heat exercise training may increase exercise performance in athletes. The underlying mechanisms remain partly unresolved, and it is unknown if female and male athletes may experience comparable gains. The aims were to investigate whether heat training (HEAT) increases hemoglobin mass (Hbmass), skeletal muscle fiber characteristics and thermoneutral exercise performance in elite female and male endurance athletes. Female (n=20; VO2max = 58.2 ± 6.7 ml.min.kg) and male (n=27; VO2max = 76.4 ± 7.8 ml.min.kg) cyclists were studied before and after five weeks of randomized control or HEAT training consisting of five weekly sessions each of 50 min duration which were included in their normal training regimes. Overall, the observed relative responses to HEAT were largely similar in female and male study participants. HEAT increased (P<0.05) Hbmass in female from 650 ± 77 to 675 ± 76 g (4.0 ± 1.6%) and from 1008 ± 155 to 1041 ± 147 g (3.5 ± 2.3%) in male. In contrast, skeletal muscle citrate synthase activity, fiber type distribution and capillary density remained unchanged with HEAT. Lactate threshold, VO2max and mean power output during 15 min all out testing were all enhanced (P<0.05) following HEAT in female and male study participants. In conclusion, five weeks of HEAT increases Hbmass in female and male elite cyclists and improves exercise performance in a thermoneutral environment. Based on this, heat training may be recommended to elite female and male athletes aiming to perform in a thermoneutral environment.

Inpatient stroke survivors with low gait functioning benefit from music interventions during cardiorespiratory exercise: A randomized cross-over trial

ABSTRACT Introduction Stroke survivors struggle to meet clinical recommendations for physical exercise duration and intensity. During the past two decades, emerging evidence has shown effectiveness of music interventions for several motor tasks in stroke rehabilitation. Additionally, music has been found effective for increasing exercise performance in athletes and clinical populations. It is postulated that the therapeutic effects of music in physical exercise are modulated by preference and task-specificity of the music. Methods We tested this hypothesis in a pilot study using a three-arm randomized cross-over design comprising the following auditory conditions during cycle ergometry cardiorespiratory exercise sessions: (a) a group-tailored music playlist, (b) radio music, and (c) a non-music control condition. Participants (n = 19) were inpatient stroke survivors undergoing rehabilitation between 2 and 12 weeks post infarct. Results Our results demonstrate that clinical characteristics are an important determinant for identifying patients who can benefit from music. Specifically, participants with a higher level of gait functioning experienced no benefit, whereas participants with a low level of gait functioning showed an increase in both exercise duration (M = 4.46 minutes) and time spent in the recommended heart rate intensity (M = 6.39 and M = 2.49 minutes for the playlist and radio condition, respectively). Discussion The findings suggest a beneficial role of music in rehabilitation of stroke patients with low gait functioning. Future studies should ultimately disentangle which musical parameters are more likely to induce the putative ergogenic effects. Trial registry number: NCT05398575.

Markers of Low Energy Availability in Overreached Athletes: A Systematic Review and Meta-analysis

Overreaching is the transient reduction in performance that occurs following training overload and is driven by an imbalance between stress and recovery. Low energy availability (LEA) may drive underperformance by compounding training stress; however, this has yet to be investigated systematically. The aim of this study was to quantify changes in markers of LEA in athletes who demonstrated underperformance, and exercise performance in athletes with markers of LEA. Studies using a ≥ 2-week training block with maintained or increased training loads that measured exercise performance and markers of LEA were identified using a systematic search following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Changes from pre- to post-training were analyzed for (1) markers of LEA in underperforming athletes and (2) performance in athletes with ≥ 2 markers of LEA. From 56 identified studies, 14 separate groups of athletes demonstrated underperformance, with 50% also displaying ≥ 2 markers of LEA post-training. Eleven groups demonstrated ≥ 2 markers of LEA independent of underperformance and 37 had no performance reduction or ≥ 2 markers of LEA. In underperforming athletes, fat mass (d = - 0.29, 95% confidence interval [CI] - 0.54 to - 0.04; p = 0.02), resting metabolic rate (d = - 0.63, 95% CI - 1.22 to - 0.05; p = 0.03), and leptin (d = - 0.72, 95% CI - 1.08 to - 0.35; p < 0.0001) were decreased, whereas body mass (d = - 0.04, 95% CI - 0.21 to 0.14; p = 0.70), cortisol (d = - 0.06, 95% CI - 0.35 to 0.23; p = 0.68), insulin (d = - 0.12, 95% CI - 0.43 to 0.19; p = 0.46), and testosterone (d = - 0.31, 95% CI - 0.69 to 0.08; p = 0.12) were unaltered. In athletes with ≥ 2 LEA markers, performance was unaffected (d = 0.09, 95% CI - 0.30 to 0.49; p = 0.6), and the high heterogeneity in performance outcomes (I2 = 84.86%) could not be explained by the performance tests used or the length of the training block. Underperforming athletes may present with markers of LEA, but overreaching is also observed in the absence of LEA. The lack of a specific effect and high variability of outcomes with LEA on performance suggests that LEA is not obligatory for underperformance.

Low-frequency high-intensity interval training improves maximal cardiorespiratory function and exercise performance in athletes

Low-frequency high-intensity interval training improves maximal cardiorespiratory function and exercise performance in athletes

Exercise Performance Upregulatory Effect of R-α-Lipoic Acid with γ-Cyclodextrin.

α-Lipoic acid (ALA) is a vitamin-like substance that is an indispensable supporting factor for a large number of enzymes. Due to its optical activity, ALA has optical isomers RALA and SALA. The major role of RALA is in energy metabolism. However, RALA cannot be used as a pharmaceutical or nutraceutical because it is sensitive to heat and acid conditions. Previous studies have shown that RALA complexed with γ-cyclodextrin (CD) has a higher antioxidant capacity than that of free RALA. The antioxidant enzyme system protects against intense exercise-induced oxidative damage and is related to the physical status of athletes. The aim of this study was to examine the effect of CD/RALA complex supplementation on antioxidant activity and performance during high-intensity exercise. Twenty-four male C3H/HeSlc mice were divided into four groups (n = 6): swimming+distilled water administration (C), swimming+CD/RALA supplementation (CD/RALA), swimming+RALA suplementation (RALA), and swimming+CD supplementation (CD). Blood ammonia elevation due to exercise stress was repressed by CD/RALA supplementation. The oxidative stress in the kidney increased after exercise and was reduced by CD/RALA supplementation. Our findings suggest that CD/RALA supplementation may be useful for improving the exercise performance in athletes.

Recent Advance on Vitamin D in Athletes

PURPOSE: Vitamin D plays important roles in calcium homeostasis and bone metabolism. Since vitamin D receptors (VDRs) are located in a variety of organs, including skeletal muscle, vitamin D has potentially widespread effects. The purpose of this review was to summarize the current understanding of the effects of vitamin D on muscle function and exercise performance in athletes.METHODS: In this narrative review, we summarized previous studies by searching the literature in the PubMed, Google Scholar, and Science Direct databases.RESULTS: Vitamin D has been shown to regulate multiple actions in skeletal muscle tissue, such as myocyte proliferation and growth via genomic and non-genomic molecular pathways. Higher levels of vitamin D are associated with improved skeletal muscle function and exercise performance. Moreover, in some studies, vitamin D supplementation has beneficial effects on muscle strength in athletes, especially those who are vitamin D-deficient.CONCLUSIONS: Vitamin D appears to have beneficial effects on muscle and exercise performance in athletes. However, more studies are needed to clarify the action and dosage of vitamin D in athletes.

Acute beetroot juice supplementation improves exercise tolerance and cycling efficiency in adults with obesity.

BackgroundExercise training improves health outcomes in individuals with obesity (IO); however, it remains challenging for IO to adhere to exercise. Thus, it is critical to identify novel strategies that improve exercise tolerance (ET) and adherence in IO. Beetroot juice (BRJ), high in inorganic dietary nitrate, consistently improves exercise performance in athletes, individuals with cardiopulmonary diseases, and nonobese lean individuals. These improvements may be explained by reduced oxygen uptake (VO2) during exercise, enhanced blood flow, and greater mitochondrial efficiency. To date, we are aware of no studies that have compared the effects of BRJ, sodium nitrate (NaNO3), and nitrate‐depleted BRJ (PLA) for improving ET and cardiometabolic health in IO.PurposeDetermine if BRJ improves ET, exercise efficiency (EE), and cardiometabolic health in IO and identify possible mechanisms of action.MethodsVascular hemodynamic, submaximal‐ and maximal‐exercise VO2, and time to exhaustion (TTE) were assessed in 16 participants 2.5 hr following consumption of: 1) BRJ, 2) NaNO3, 3) PLA, or 4) CON.ResultsA significant treatment effect was observed for submaximal exercise VO2 (p = .003), and TTE (p < .001). Post hoc analyses revealed lower VO2 during submaximal exercise in BRJ compared to PLA (p = .009) NaNO3 (p = .042) and CON (0.009), equating to an average improvement of ~ 7% with BRJ. TTE was greater for BRJ compared to other treatment arms, PLA (p = .008), NaNO3 (p = .038), and CON (p=<0.001), equating to ~ 15% improvement with BRJ. No significant changes were observed for other outcomes.ConclusionsConsumption of BRJ improved EE during submaximal exercise by 7%, and TTE by 15% compared to other conditions. These results suggest that BRJ may improve EE and exercise tolerance in IO.

Effects Of Beetroot Juice Components On Exercise Tolerance And Cardiometabolic Health In Individuals With Obesity

Routine exercise training is known to improve health outcomes in individuals with obesity (IO); however it remains challenging for IO to adhere to exercise programs. Thus, it is critical to identify novel strategies that can improve exercise capacity (EC) and lead to greater adherence in IO. Beetroot juice (BRJ), high in inorganic dietary nitrate, has been shown to consistently improve exercise performance in athletes, individuals with cardiopulmonary diseases, and non-obese lean individuals. These improvements may be explained by reduced oxygen uptake (VO2) during exercise, enhanced blood flow, and greater mitochondrial efficiency. To date, we are aware of no studies that have compared the effects of BRJ, sodium nitrate (NaNO3), denitrilized BRJ (PLA), and control (CON) conditions for improving EC and cardiometabolic health in IO. PURPOSE: to determine if BRJ improves EC, exercise efficiency (EE) and cardiometabolic health in IO and identify possible mechanisms of action. METHODS: Vascular health (blood pressure and arterial elasticity), VO2 on a cycle ergometer during submaximal- and maximal- exercise, and time to exhaustion (TTE) were assessed in 16 sedentary IO in a crossover design for the following 4 conditions: 1) consumption of BRJ, 2) NaNO3, 3) PLA, or 4) CON. Study visits were at least 72 hours apart. RESULTS: A significant treatment effect was observed for submaximal exercise VO2 (p=0.003), and TTE (seconds) (p=0.035). Post hoc analyses demonstrated a lower VO2 during submaximal exercise in BRJ compared to PLA (P=0.009) NaNO3 (P=0.042) and CON (0.009). TTE was greater between BRJ and CON (P=0.029) with no other differences observed between conditions. No other significant changes were observed for other exercise or vascular health measures. In this analysis of 16 IO, consumption of BRJ improved EE during submaximal cycling exercise by 5.28% compared to PLA, 5.91% compared to the NaNO3, and 4.22% compared to CON. Finally, BRJ resulted in a 19% improvement in TTE compared to CON condition. CONCLUSION: These results suggest that consumption of BRJ may improve cycling efficiency and exercise capacity in IO.

성별 및 성숙 단계별 운동선수의 신체조성과 운동수행력의 상관성 연구

The purpose of this study was to investigate the association study between body composition and exercise performance according to sex differences and stages of maturation in athletes. Data collection selected 4,560 were used for final analysis from elementary, middle, high school, and adults athletes. All subject were tested for body composition and exercise performance. The positively (+) correlate between weigh and hand grip in man elementary/middle/high school and woman elementary/middle school athletes, between height and hand grip in man middle school and woman elementary/middle school athletes, between percent body fat and hand grip in woman elementary/middle school athletes, between standing long jump and sargent jump in man elementary/middle/high school and woman elementary/middle/high /school and adults athletes, between standing long jump and hand grip in man middle school athletes, between 20 m run and side-step in man elementary school and woman elementary school athletes, between 20 m run and sit-up in woman elementary school athletes, between 20 m run and sargent jum in woman elementary school athletes, respectively. These results of this study found that body composition and exercise performance of athletes by sex differences and stages of maturation have a variety of relationships.

Effects of Dioscorea esculenta intake with resistance training on muscle hypertrophy and strength in sprint athletes.

Androgen hormones are important compounds related to body composition and exercise performance in athletes. The intake of Dioscorea esculenta, known as lesser yam, contains diosgenin and resistance training have been shown to normalize the secretion of androgen hormones. This study aimed to clarify the level of androgen hormone secretion and the effects of Dioscorea esculenta intake with resistance training on muscle hypertrophy and strength in athletes. First, in a cross-sectional study, we compared the serum androgen hormone [dehydroepiandrosterone (DHEA), testosterone, and 5α-dihydrotestosterone (DHT)] levels between sprint athletes (n = 15) and non-athletes (n = 15). Second, in an 8-week intervention study, sprint athletes were randomly divided into 2 groups: resistance training with placebo (n = 8) or with Dioscorea esculenta (2,000 mg/day) intake (n = 7). The serum DHEA, free testosterone, and DHT levels were lower in athletes than in non-athletes. Dioscorea esculenta intake combined with resistance training increased the arm fat-free mass, the 1 repetition maximum of deadlift and snatch, and the serum DHEA, free testosterone, and DHT levels, compared with resistance training and placebo intake. The results suggested that Dioscorea esculenta intake combined with resistance training has further effects on muscle hypertrophy and strength in athletes by restoring secretion of androgen hormones.

Can microbes increase exercise performance in athletes?

Faecal microbiota transplantation (FMT) has been suggested to be a therapeutic strategy for inflammatory diseases and it is known that regular physical activity can alter the composition of the gut microbiota. Now, a study proposes that FMT might increase exercise performance in athletes, raising the possibility of ‘faecal doping’.

Cobalt in athletes: hypoxia and doping - new crossroads.

Cobalt is an essential trace element that is known to mimic hypoxia and hypoxic training. Inorganic Co compounds are capable of Hypoxia-inducible factor-1 (HIF-1) activation, resulting in up-regulation of gene expression including erythropoietin (Epo). Experimental studies have demonstrated that Co treatment may increase hypoxic tolerance of different tissues, improve muscle metabolism and exercise performance. Other mechanisms may also involve modulation of steroid hormone and iron metabolism. Based on these experimental studies, in 2017 inorganic cobalt compounds were added into the World Anti-Doping Agency (WADA) prohibited list as doping agents. However, the existing data on beneficial effects of cobalt on exercise performance in athletes are scarce. Similarly, only experimental studies demonstrated exercise-induced decrease in tissue Co levels, whereas human data are inconsistent. In addition, multiple studies have demonstrated that excessive Co intake may be toxic due to prooxidant, proinflammatory, and proapoptotic activity. Therefore, monitoring of Co deficiency and overload is required to prevent potential health hazards in athletes. At the same time, modulation of Co status should be performed through supplementation avoiding excessive doses of inorganic cobalt that are used for doping and are accompanied by adverse health effects of metal toxicity.

Low-level mitochondrial heteroplasmy modulates DNA replication, glucose metabolism and lifespan in mice

Mutations in mitochondrial DNA (mtDNA) lead to heteroplasmy, i.e., the intracellular coexistence of wild-type and mutant mtDNA strands, which impact a wide spectrum of diseases but also physiological processes, including endurance exercise performance in athletes. However, the phenotypic consequences of limited levels of naturally arising heteroplasmy have not been experimentally studied to date. We hence generated a conplastic mouse strain carrying the mitochondrial genome of an AKR/J mouse strain (B6-mtAKR) in a C57BL/6 J nuclear genomic background, leading to >20% heteroplasmy in the origin of light-strand DNA replication (OriL). These conplastic mice demonstrate a shorter lifespan as well as dysregulation of multiple metabolic pathways, culminating in impaired glucose metabolism, compared to that of wild-type C57BL/6 J mice carrying lower levels of heteroplasmy. Our results indicate that physiologically relevant differences in mtDNA heteroplasmy levels at a single, functionally important site impair the metabolic health and lifespan in mice.

Effects of Grape Seed Extract Supplementation on Exercise Performance in Athletes

Effects of Grape Seed Extract Supplementation on Exercise Performance in Athletes

Quality of life of female and male vegetarian and vegan endurance runners compared to omnivores \u2013 results from the NURMI study (step 2)

BackgroundHealth-related effects of a vegetarian or vegan diet are known to support parameters positively affecting exercise performance in athletes, whereas knowledge about psyche and wellbeing is sparse. Therefore, the aim of the Nutrition and Running High Mileage (NURMI) Study (Step 2) was to compare Quality of Life (QOL) scores among endurance runners following a vegetarian or vegan diet against those who adhere to an omnivorous diet.MethodsThe study was conducted following a cross-sectional design. A total of 281 recreational runners (159 women, 122 men) completed the WHOQOL-BREF questionnaire consisting of the domains physical health, psychological wellbeing, social relationships and environment, which generates scores on a scale from 4 to 20. Data analysis was performed using ANOVA.ResultsIt was found that 123 subjects followed an omnivorous diet and 158 adhered to a vegetarian/vegan diet. There were 173 runners who met the inclusion criteria (‘NURMI-Runners’), among them 103 half-marathoners and 70 marathoners and ultramarathoners, as well as 108 10 km runners as control group. Overall QOL scores were high (~ 16.62 ± 1.91). Men had higher scores than women due to high scores in the physical health and psychological well-being dimensions. Adhering to an omnivorous diet affected environment scores for women and social relationships scores for men. A minor effect concerning race distance was observed in women, where half-marathoners had a higher environmental score than 10-km runners. A moderate diet×race distance interaction on environment scores was shown for men.ConclusionsThe results revealed that endurance runners had a high QOL regardless of the race distance or diet choice. These findings support the notion that adhering to a vegetarian or vegan diet can be an appropriate and equal alternative to an omnivorous diet.Trial registrationISRCTN73074080. Registered 12th June 2015, retrospectively registered.

Autophagy Is a Promoter for Aerobic Exercise Performance during High Altitude Training.

High altitude training is one of the effective strategies for improving aerobic exercise performance at sea level via altitude acclimatization, thereby improving oxygen transport and/or utilization. But its underlying molecular mechanisms on physiological functions and exercise performance of athletes are still vague. More recent evidence suggests that the recycling of cellular components by autophagy is an important process of the body involved in the adaptive responses to exercise. Whether high altitude training can activate autophagy or whether high altitude training can improve exercise performance through exercise-induced autophagy is still unclear. In this narrative review article, we will summarize current research advances in the improvement of exercise performance through high altitude training and its reasonable molecular mechanisms associated with autophagy, which will provide a new field to explore the molecular mechanisms of adaptive response to high altitude training.

Effect of Ischemic Preconditioning on Endurance Performance Does Not Surpass Placebo.

Recent studies have reported ischemic preconditioning (IPC) can acutely improve endurance exercise performance in athletes. However, placebo and nocebo effects have not been sufficiently controlled, and the effect on aerobic metabolism parameters that determine endurance performance (e.g., oxygen cost of running, lactate threshold, and maximal oxygen uptake [V˙O2max]) has been equivocal. Thus, we circumvented limitations from previous studies to test the effect of IPC on aerobic metabolism parameters and endurance performance in well-trained runners. Eighteen runners (14 men/4 women) were submitted to three interventions, in random order: IPC; sham intervention (SHAM); and resting control (CT). Subjects were told both IPC and SHAM would improve performance compared to CT (i.e., similar placebo induction), and IPC would be harmless despite circulatory occlusion sensations (i.e., nocebo avoidance). Next, pulmonary ventilation and gas exchange, blood lactate concentration, and perceived effort were measured during a discontinuous incremental test on a treadmill. Then, a supramaximal test was used to verify the V˙O2max and assess endurance performance (i.e., time to exhaustion). Ventilation, oxygen uptake, carbon dioxide output, lactate concentration, and perceived effort were similar among IPC, SHAM, and CT throughout the discontinuous incremental test (P > 0.05). Oxygen cost of running, lactate threshold, and V˙O2max were also similar among interventions (P > 0.05). Time to exhaustion was longer after IPC (mean ± SEM, 165.34 ± 12.34 s) and SHAM (164.38 ± 11.71 s) than CT (143.98 ± 12.09 s; P = 0.02 and 0.03, respectively), but similar between IPC and SHAM (P = 1.00). IPC did not change aerobic metabolism parameters, whereas improved endurance performance. The IPC improvement, however, did not surpass the effect of a placebo intervention.

Muscular effects of vitamin D in young athletes and non-athletes and in the elderly.

Muscles are major targets of vitamin D. Exposure of skeletal muscles to vitamin D induces the expression of multiple myogenic transcription factors enhancing muscle cell proliferation and differentiation. At the same time vitamin D suppresses the expression of myostatin, a negative regulator of muscle mass. Moreover, vitamin D increases the number of type II or fast twitch muscle cells and in particular that of type IIA cells, while its deficiency causes type IIA cell atrophy. Furthermore, vitamin D supplementation in young males with low vitamin D levels increases the percentage of type IIA fibers in muscles, causing an increase in muscular high power output. Vitamin D levels are strongly associated with exercise performance in athletes and physically active individuals. In the elderly and in adults below the age of 65, several studies have established a close association between vitamin D levels and neuromuscular coordination. The aim of this review is to appraise our current understanding of the significance of vitamin D on muscular performance in both older and frail individuals as well as in younger adults, athletes or non-athletes with regard to both ordinary everyday musculoskeletal tasks and peak athletic performance.

Exploring the Potential of Cell-Free-DNA Measurements After an Exhaustive Cycle-Ergometer Test as a Marker for Performance-Related Parameters

Intensive exercise is known to be accompanied by a rapid release of cell-free DNA (cfDNA). The physiological significance of cfDNA release for performance diagnostics has not been studied. The authors analyzed the release of cfDNA during bicycle exercise and its correlation with physiological parameters. Eleven male athletes performed an incremental cycling test. Venous blood was collected before and immediately after exercise and after 90 min of recovery. Since the amount of cfDNA is influenced by preanalytical parameters like DNA extraction and quantification method, the authors applied different measurement approaches based on quantitative real-time polymerase chain reaction. They compared a direct measurement procedure not requiring cfDNA extraction for a short (L1PA290) and a long fragment (L1PA2222) and a procedure for extracted cfDNA for a short (LTR570) and long fragment (LTR5323) with primers targeting the repetitive sequences L1PA2 and LTR5 in both assays, respectively. With the exception of LTR5323, the procedures revealed significant increases of cfDNA postexercise, whereas the direct approach showed lower interindividual variance in cfDNA values. When linking cfDNA levels to parameters of exercise performance the authors observed that, especially, the measurement based on L1PA2222 correlated significantly with exercise markers. These correlations were similar to the relationship of the performance markers among themselves. cfDNA is a possible physiological marker to assess and predict exercise performance in athletes. In addition, the results indicate that using cfDNA as a marker in exercise physiology requires careful selection of a suitable measurement technique, whether it is eluted DNA or directly quantified.