Exercise Performance and Physiological Responses: The Potential Role of Redox Imbalance

Increases in oxidative stress or decreases in antioxidant capacity, or redox imbalance, are known to alter physiological function and has been suggested to influence performance. To date, no study has sought to manipulate this balance in the same participants and observe the impact on physiological function and performance. Using a single-blind, placebo-controlled, and counterbalanced design, this study examined the effects of increasing free radicals, via hyperoxic exposure (FiO2 = 1.0), and/or increasing antioxidant capacity, through consuming an antioxidant cocktail (AOC; vitamin-C, vitamin-E, α-lipoic acid), on 5-kilometer (km) cycling time-trial performance, and the physiological and fatigue responses in healthy college-aged males. Hyperoxic exposure prior to the 5 km TT had no effect on performance, fatigue, or the physiological responses to exercise. The AOC significantly reduced average power output (222 ± 11 vs. 214 ± 12 W), increased 5 km time (516 ± 17 vs. 533 ± 18 sec), suppressed ventilation (VE; 116 ± 5 vs. 109 ± 13 L/min), despite similar oxygen consumption (VO2; 43.1 ± 0.8 vs. 44.9 ± 0.2 mL/kg per min), decreased VE/VO2 (35.9 ± 2.0 vs. 32.3 ± 1.5 L/min), reduced economy (VO2/W; 0.20 ± 0.01 vs. 0.22 ± 0.01), increased blood lactate (10 ± 0.7 vs. 11 ± 0.7 mmol), and perception of fatigue (RPE; 7.39 ± 0.4 vs. 7.60 ± 0.3) at the end of the TT, as compared to placebo (main effect, placebo vs. AOC, respectively). Our data demonstrate that prior to exercise, ingesting an AOC, but not exposure to hyperoxia, likely disrupts the delicate balance between pro- and antioxidant forces, which negatively impacts ventilation, blood lactate, economy, perception of fatigue, and performance (power output and 5 km time) in young healthy males. Thus, caution is warranted in athletes taking excess exogenous antioxidants

The Effect of Concurrent Plyometric Training Versus Submaximal Aerobic Cycling on Rowing Economy, Peak Power, and Performance in Male High School Rowers

BACKGROUND: Plyometric training has been shown to increase muscle power, running economy, and performance in athletes. Despite its use by rowing coaches, it is unknown whether plyometrics might improve rowing economy or performance. The purpose was to determine if plyometric training, in conjunction with training on the water, would lead to improved rowing economy and performance. METHODS: Eighteen male high school rowers were assigned to perform 4 weeks of either plyometric training (PLYO, n = 9) or steady-state cycling below ventilatory threshold (endurance, E, n = 9), for 30 min prior to practice on the water (matched for training volume) 3 days per week. Rowing performance was assessed through a 500-m rowing time trial (TT) and peak rowing power (RP), while rowing economy (RE) was assessed by measuring the oxygen cost over four work rates (90, 120, 150, and 180 W). RESULTS: Rowing economy was improved in both PLYO and E (p \u3c 0.05). The 500-m TT performance improved significantly for PLYO (from 99.8 ± 9 s to 94.6 ± 2 s, p \u3c 0.05) but not for E (from 98.8 ± 6 s to 98.7 ± 5 s, p \u3e 0.05). Finally, RP was moderately higher in the PLYO group post-training (E 569 ± 75 W, PLYO 629 ± 51 W, ES = 0.66) CONCLUSIONS: In a season when the athletes performed no rowing sprint training, 4 weeks of plyometric training improved the 500-m rowing performance and moderately improved peak power. This increase in performance may have been mediated by moderate improvements in rowing power, but not economy, and warrants further investigation

Bilateral Differences in Vascular Stiffness and Blood Pressure of Female College Tennis Players and Controls

Vascular stiffness is highly correlated to cardiovascular disease (CVD) and has been attenuated by regular aerobic exercise in older adults. Additionally, body composition strongly predicts vascular stiffness and CVD risk. Previous research has documented that bilateral differences in shear stress lead to differences in vascular endothelial function in tennis players. However, whether this translates into bilateral differences in vascular stiffness and blood pressure remains to be elucidated. The SphygmoCor is a gold standard for assessing arterial stiffness but is not readily accessible. In comparison, the TicWatch GTH Pro, which uses the SphygmoCor algorithm to provide a cardiovascular health (CVH) score (ARTY score), could be a feasible way to monitor CVH, but its accuracy is unknown. PURPOSE: This study aimed to evaluate bilateral differences in vascular stiffness and blood pressure in Division III female college tennis players and recreationally active female students. A secondary aim was to determine if the TicWatch GTH Pro ARTY score relates to SphygmoCor outcomes. METHODS: Subjects from the Skidmore women’s tennis team (n=10) and recreationally active female students (n=10) underwent a single testing session where anthropometrics, body composition, bilateral cardiovascular measurements, and a TicWatch analysis were performed. RESULTS: There were no significant differences in weight, body fat percentage, or BMI between the two groups (p=0.96; p=0.83; p=0.69). Augmentation pressure and augmentation index were different between the dominant and non-dominant arms (p=0.02; p=0.02), but no interactions of the group by arm were observed (all, p\u3e0.05). In addition, the TicWatch ARTY score related significantly with brachial diastolic pressure, mean arterial pressure, and central diastolic pressure (r²= -0.52; r²= -0.50; r²= -0.56). CONCLUSION: In groups well-matched for age and body composition, two indices of vascular stiffness significantly differed between the arms, but this did not appear specific to this cohort of tennis players. The results also indicate that the TicWatch is an accurate device for assessing CVH indicators and may predict brachial diastolic pressure, central diastolic pressure, and mean arterial pressure

Effective management of ecological resilience – are we there yet?

1. Ecological resilience is developing into a credible paradigm for policy development and environmental management for preserving natural capital in a rapidly changing world. However, resilience emerges from complex interactions, limiting the translation of theory into practice. 2. Main limitations include the following: (i) difficulty in quantification and detection of changes in ecological resilience, (ii) a lack of empirical evidence to support preventative or proactive management and (iii) difficulties in managing processes operating across socio-ecological systems that vary in space and time. 3. We highlight recent research with the potential to address these limitations including new and/or improved indicators of resilience and tools to assess scale as a driver of resilience. 4. Synthesis and applications. Effective resilience-based management must be adaptive in nature. To support this, we propose an operational model using resilience-based iterative management actions operating across scales

Capsaicin and its effect on exercise performance, fatigue and inflammation after exercise

Capsaicin (CAP) activates the transient receptor potential vanilloid 1 (TRPV1) channel on sensory neurons, improving ATP production, vascular function, fatigue resistance, and thus exercise performance. However, the underlying mechanisms of CAP-induced ergogenic effects and fatigue-resistance, remain elusive. To evaluate the potential anti-fatigue effects of CAP, 10 young healthy males performed constant-load cycling exercise time to exhaustion (TTE) trials (85% maximal work rate) after ingestion of placebo (PL; fiber) or CAP capsules in a blinded, counterbalanced, crossover design, while cardiorespiratory responses were monitored. Fatigue was assessed with the interpolated twitch technique, pre-post exercise, during isometric maximal voluntary contractions (MVC). No significant differences (p > 0.05) were detected in cardiorespiratory responses and self-reported fatigue (RPE scale) during the time trial or in TTE (375 ± 26 and 327 ± 36 s, respectively). CAP attenuated the reduction in potentiated twitch (PL: -52 ± 6 vs. CAP: -42 ± 11%, p = 0.037), and tended to attenuate the decline in maximal relaxation rate (PL: -47 ± 33 vs. CAP: -29 ± 68%, p = 0.057), but not maximal rate of force development, MVC, or voluntary muscle activation. Thus, CAP might attenuate neuromuscular fatigue through alterations in afferent signaling or neuromuscular relaxation kinetics, perhaps mediated via the sarco-endoplasmic reticulum Ca2+ ATPase (SERCA) pumps, thereby increasing the rate of Ca2+ reuptake and relaxation

Protein-Pacing and Multi-Component Exercise Training Improves Physical Performance Outcomes in Exercise-Trained Women: The PRISE 3 Study

The beneficial cardiometabolic and body composition effects of combined protein-pacing (P; 5-6 meals/day at 2.0 g/kg BW/day) and multi-mode exercise (resistance, interval, stretching, endurance; RISE) training (PRISE) in obese adults has previously been established. The current study examines PRISE on physical performance (endurance, strength and power) outcomes in healthy, physically active women. Thirty exercise-trained women (\u3e4 days exercise/week) were randomized to either PRISE (n = 15) or a control (CON, 5-6 meals/day at 1.0 g/kg BW/day; n = 15) for 12 weeks. Muscular strength (1-RM bench press, 1-RM BP) endurance (sit-ups, SUs; push-ups, PUs), power (bench throws, BTs), blood pressure (BP), augmentation index, (AIx), and abdominal fat mass were assessed at Weeks 0 (pre) and 13 (post). At baseline, no differences existed between groups. Following the 12-week intervention, PRISE had greater gains (p \u3c 0.05) in SUs, PUs (6 ± 7 vs. 10 ± 7, 40%; 8 ± 13 vs. 14 ± 12, 43% ∆reps, respectively), BTs (11 ± 35 vs. 44 ± 34, 75% ∆watts), AIx (1 ± 9 vs. -5 ± 11, 120%), and DBP (-5 ± 9 vs. -11 ± 11, 55% ∆mmHg). These findings suggest that combined protein-pacing (P; 5-6 meals/day at 2.0 g/kg BW/day) diet and multi-component exercise (RISE) training (PRISE) enhances muscular endurance, strength, power, and cardiovascular health in exercise-trained, active women

Listening to Voices: Understanding and Self-Management of Auditory Verbal Hallucinations in Young Adults

Aims Auditory Verbal Hallucinations (AVH) are a hallmark of psychosis, but affect many other clinical populations. Patients’ understanding and self-management of AVH may differ between diagnostic groups, change over time, and influence clinical outcomes. We aimed to explore patients’ understanding and self-management of AVH in a young adult clinical population. Method 35 participants reporting frequent AVH were purposively sampled from a youth mental health service, to capture experiences across psychosis and non-psychosis diagnoses. Diary and photo-elicitation methodologies were used – participants were asked to complete diaries documenting experiences of AVH, and to take photographs representing these experiences. In-depth, unstructured interviews were held, using participant-produced materials as a topic guide. Conventional content analysis was conducted, deriving results from the data in the form of themes. Result Three themes emerged: (1)Searching for answers, forming identities – voice-hearers sought to explain their experiences, resulting in the construction of identities for voices, and descriptions of relationships with them. These identities were drawn from participants’ life-stories (e.g., reflecting trauma), and belief-systems (e.g., reflecting supernatural beliefs, or mental illness). Some described this process as active / volitional. Participants described re-defining their own identities in relation to those constructed for AVH (e.g. as diseased, 'chosen', or persecuted), others considered AVH explicitly as aspects of, or changes in, their personality. (2)Coping strategies and goals – patients’ self-management strategies were diverse, reflecting the diverse negative experiences of AVH. Strategies were related to a smaller number of goals, e.g. distraction, soothing overwhelming emotions, 'reality-checking', and retaining agency. (3)Outlook – participants formed an overall outlook reflecting their self-efficacy in managing AVH. Resignation and hopelessness in connection with disabling AVH are contrasted with outlooks of “acceptance” or integration, which were described as positive, ideal, or mature. Conclusion Trans-diagnostic commonalities in understanding and self-management of AVH are highlighted - answer-seeking and identity-formation processes; a diversity of coping strategies and goals; and striving to accept the symptom. Descriptions of “voices-as-self”, and dysfunctional relationships with AVH, could represent specific features of voice-hearing in personality disorder, whereas certain supernatural/paranormal identities and explanations were clearly delusional. However, no aspect of identity-formation was completely unique to psychosis or non-psychosis diagnostic groups. The identity-formation process, coping strategies, and outlooks can be seen as a framework both for individual therapies and further research

TRPV1 channels in human skeletal muscle feed arteries: implications for vascular function

New Findings What is the central question of this study? We sought to determine whether human skeletal muscle feed arteries (SFMAs) express TRPV1 channels and what role they play in modulating vascular function. What is the main finding and its importance? Human SMFAs do express functional TRPV1 channels that modulate vascular function, specifically opposing α-adrenergic receptor-mediated vasocontraction and potentiating vasorelaxation, in an endothelium-dependent manner, as evidenced by the α1-receptor-mediated responses. Thus, the vasodilatory role of TRPV1 channels, and their ligand capsaicin, could be a potential therapeutic target for improving vascular function. Additionally, given the ‘sympatholytic’ effect of TRPV1 activation and known endogenous activators (anandamide, reactive oxygen species, H+, etc.), TRPV1 channels might contribute to functional sympatholysis during exercise. To examine the role of the transient receptor potential vanilloid type 1 (TRPV1) ion channel in the vascular function of human skeletal muscle feed arteries (SMFAs) and whether activation of this heat-sensitive receptor could be involved in modulating vascular function, SMFAs from 16 humans (63 ± 5 years old, range 41–89 years) were studied using wire myography with capsaicin (TRPV1 agonist) and without (control). Specifically, phenylephrine (α1-adrenergic receptor agonist), dexmedetomidine (α2-adrenergic receptor agonist), ACh and sodium nitroprusside concentration–response curves were established to assess the role of TRPV1 channels in α-receptor-mediated vasocontraction as well as endothelium-dependent and -independent vasorelaxation, respectively. Compared with control conditions, capsaicin significantly attenuated maximal vasocontraction in response to phenylephrine [control, 52 ± 8% length–tensionmax (LTmax) and capsaicin, 21 ± 5%LTmax] and dexmedetomidine (control, 29 ± 12%LTmax and capsaicin, 2 ± 3%LTmax), while robustly enhancing maximal vasorelaxation with ACh (control, 78 ± 8% vasorelaxation and capsaicin, 108 ± 13% vasorelaxation) and less clearly enhancing the sodium nitroprusside response. Denudation of the endothelium greatly attenuated the maximal ACh-induced vasorelaxation equally in the control and capsaicin conditions (∼17% vasorelaxation) and abolished the attenuating effect of capsaicin on the maximal phenylephrine response (denuded + capsaicin, 61 ± 20%LTmax). Immunohistochemistry identified a relatively high density of TRPV1 channels in the endothelium compared with the smooth muscle of the SMFAs, but because of the far greater volume of smooth muscle, total TRPV1 protein content was not significantly attenuated by denudation. Thus, SMFAs ubiquitously express functional TRPV1 channels, which alter vascular function, in terms of α1-receptors, in a predominantly endothelium-dependent manner, conceivably contributing to the functional sympatholysis and unveiling a therapeutic target