Bout Of Exercise Research Articles

O002 High strain evening exercise disrupts sleep: Insights from a real-world examination of ~7-million nights

Abstract Introduction Exercise is among the most effective daytime behaviors for promoting and maintaining sleep. However, late-night bouts of strenuous exercise that require high physiological demand (i.e., high strain) induce persistent increases in sympathetic arousal, which may disrupt sleep. We examined whether exercise strain moderates the relationship between evening exercise and objective sleep in free-living conditions. Methods A total of 19,977 individuals (26% female, M-age=37.9 years) wore a validated sleep and exercise biometric wearable device for 365 days between Sep 1, 2021 and Aug 31, 2022 (n=6,943,372 nights). Summated-heart-rate-zone-scores were used to categorize exercise strain into four groups: light, moderate, high, and all-out. Exercise timing was normalized to each individual’s habitual bedtime to account for individual differences in sleep/wake timing. Generalized additive mixed model analyses were used to model the non-linear relationship between exercise timing and sleep at different levels of exercise strain. Results Later exercise timing was associated with delayed sleep onset, reduced sleep quantity and quality, and increased sympathetic activity compared to no-exercise rest days (ps<.001). Importantly, a dose-response relationship was observed such that higher levels of exercise strain predicted worse sleep (ps<.001). Regardless of strain, exercise bouts ending at least 4 hours before habitual bedtime were not associated with changes in sleep. Discussion Evening exercise—particularly involving high exercise strain—can disrupt subsequent sleep (both duration and quality). It is recommended individuals stop exercising at least 4 hours before their habitual bedtime. However, when evening exercise is unavoidable, individuals could select lighter strain exercises to mitigate sleep disruption.

Effects of acute exercise and training status on glucocorticoid-induced leucine zipper (GILZ) expression in human skeletal muscle

Interactions between statin therapy and physical exercise complicate effective cardiovascular prevention. Emerging evidence suggests that muscle strain related changes in the expression of the glucocorticoid-induced leucine zipper (GILZ) may be involved. Therefore, we measured GILZ mRNA expression levels in M. vastus lateralis samples of 32 healthy individuals before and after a standardized bout of strength or endurance exercise. Overall, we found a highly significant downregulation of GILZ after exercise training (p < 0.001). Within-subgroup changes were statistically significant only after strength training, supporting the role of muscle (as opposed to cardiocirculatory) strain. If confirmed, this may help fitting training recommendations and medication.

Differential effects of acute cardiovascular exercise on explicit and implicit motor memory: The moderating effects of fitness level

A single bout of cardiovascular exercise (CE) performed after practice can facilitate the consolidation of motor memory. However, the effect is variable and may be modulated by different factors such as the motor task’s or participant’s characteristics and level of awareness during encoding (implicit vs explicit learning). This study examines the effects of acute CE on the consolidation of motor sequences learned explicitly and implicitly, exploring the potential moderating effect of fitness level and awareness. Fifty-six healthy adults (24.1 ± 3.3 years, 32 female) were recruited. After practicing with either the implicit or explicit variant of the Serial Reaction Time Task (SRTT), participants either performed a bout of 16 min of vigorous CE or rested for the same amount of time. Consolidation was quantified as the change in SRTT performance from the end of practice to a 24 h retention test. Fitness level (V̇O2peak) was determined through a graded exercise test. Awareness (implicit vs explicit learning) was operationalized using a free recall test conducted immediately after retention. Our primary analysis indicated that CE had no statistically significant effects on consolidation, regardless of the SRTT’s variant utilized during practice. However, an exploratory analysis, classifying participants based on the level of awareness gained during motor practice, showed that CE negatively influenced consolidation in unfit participants who explicitly acquired the motor sequence. Our findings indicate that fitness level and awareness in sequence acquisition can modulate the interaction between CE and motor memory consolidation. These factors should be taken into account when assessing the effects of CE on motor memory.

A single bout of prior resistance exercise attenuates muscle atrophy and declines in myofibrillar protein synthesis during bed-rest in older men.

Impairments in myofibrillar protein synthesis (MyoPS) during bed rest accelerate skeletal muscle loss in older adults, increasing the risk of adverse secondary health outcomes. We investigated the effect of prior resistance exercise (RE) on MyoPS and muscle morphology during a disuse event in 10 healthy older men (65-80years). Participants completed a single bout of unilateral leg RE the evening prior to 5days of in-patient bed-rest. Quadriceps cross-sectional area (CSA) was determined prior to and following bed-rest. Serial muscle biopsies and dual stable isotope tracers were used to determine rates of integrated MyoPS (iMyoPS) over a 7day habitual 'free-living' phase and the bed-rest phase, and rates of acute postabsorptive and postprandial MyoPS (aMyoPS) at the end of bed rest. Quadriceps CSA at 40%, 60% and 80% of muscle length significantly decreased in exercised (EX) and non-exercised control (CTL) legs with bed-rest. The decline in quadriceps CSA at 40% and 60% of muscle length was attenuated in EX compared with CTL. During bed-rest, iMyoPS rates decreased from habitual values in CTL, but not EX, and were significantly different between legs. Postprandial aMyoPS rates increased above postabsorptive values in EX only. The change in iMyoPS over bed-rest correlated with the change in quadriceps CSA in CTL, but not EX. A single bout of RE attenuated the decline in iMyoPS rates and quadriceps atrophy with 5days of bed-rest in older men. Further work is required to understand the functional and clinical implications of prior RE in older patient populations. KEY POINTS: Age-related skeletal muscle deterioration, linked to numerous adverse health outcomes, is driven by impairments in muscle protein synthesis that are accelerated during periods of disuse. Resistance exercise can stimulate muscle protein synthesis over several days of recovery and therefore could counteract impairments in this process that occur in the early phase of disuse. In the present study, we demonstrate that the decline in myofibrillar protein synthesis and muscle atrophy over 5days of bed-rest in older men was attenuated by a single bout of unilateral resistance exercise performed the evening prior to bed-rest. These findings suggest that concise resistance exercise intervention holds the potential to support muscle mass retention in older individuals during short-term disuse, with implications for delaying sarcopenia progression in ageing populations.

The Effects of Exercise on Synaptic Plasticity in Individuals With Mild Cognitive Impairment: Protocol for a Pilot Intervention Study.

Mild cognitive impairment (MCI) is a syndrome preceding more severe impairment characterized by dementia. MCI affects an estimated 15% to 20% of people older than 65 years. Nonpharmacological interventions including exercise are recommended as part of overall MCI management based on the positive effects of exercise on cognitive performance. Interval training involves brief intermittent bouts of exercise interspersed with short recovery periods. This type of exercise promotes cognitive improvement and can be performed in individuals with MCI. Synaptic plasticity can be assessed in vivo by the neurophysiological response to repetitive transcranial magnetic stimulation (rTMS). A method to assess synaptic plasticity uses an intermittent theta burst stimulation (iTBS), which is a patterned form of rTMS. Individuals with MCI have decreased responses to iTBS, reflecting reduced synaptic plasticity. It is unknown whether interval training causes changes in synaptic plasticity in individuals living with MCI. This research will determine whether interval training performed using a cycle ergometer enhances synaptic plasticity in individuals with MCI. The three aims are to (1) quantify synaptic plasticity after interval training performed at a self-determined intensity in individuals with MCI; (2) determine whether changes in synaptic plasticity correlate with changes in serum brain-derived neurotrophic factor, osteocalcin, and cognition; and (3) assess participant compliance to the exercise schedule. 24 individuals diagnosed with MCI will be recruited for assignment to 1 of the 2 equally sized groups: exercise and no exercise. The exercise group will perform exercise 3 times per week for 4 weeks. Synaptic plasticity will be measured before and following the 4-week intervention. At these time points, synaptic plasticity will be measured as the response to single-pulse TMS, reflected as the percent change in the average amplitude of 20 motor-evoked potentials before and after an iTBS rTMS protocol, which is used to induce synaptic plasticity. In addition, individuals will complete a battery of cognitive assessments and provide a blood sample from the antecubital vein to determine serum brain-derived neurotrophic factor and osteocalcin. The study began in September 2023. The proposed research is the first to assess whether synaptic plasticity is enhanced after exercise training in individuals with MCI. If exercise does indeed modify synaptic plasticity, this will create a new avenue by which we can study and manipulate neural plasticity in these individuals. ClinicalTrials.gov NCT05663918; https://clinicaltrials.gov/study/NCT05663918. PRR1-10.2196/50030.

The Effects of Acute Bouts of Aerobic Exercise on Adipokine Concentrations in Individuals with Moderate Stages of Chronic Kidney Disease

This study examined the effects of two different acute bouts of treadmill running (e.g., steady-state moderate-intensity exercise (SSE) and high-intensity interval exercise (HIIE)) on adipokine (e.g., adiponectin, leptin, and omentin) concentrations in individuals with moderate stages of chronic kidney disease (CKD). Fourteen participants (8 females and 6 males) (age 58.7 ± 9.7, height (cm) 168.5 ± 9.7, weight (kg) 83.5 ± 18.2) were classified as having moderate stages of CKD (stages G3a and G3b; estimated glomerular filtration rate (eGFR) between 59 and 30 mL/min/1.73 m2). Participants completed 30 min of either SSE at 65% oxygen consumption reserve (VO2R) or HIIE for 3 min at a 90% VO2R separated by 2 min of slow walking (20% VO2R) in a randomized, crossover design on a treadmill. Venous blood samples were obtained at baseline, 1 h, and 24 h post exercise. Data were analyzed using a two by three repeated measures ANOVA (p &lt; 0.05). There were no significant differences in adiponectin (p &lt; 0.353), leptin (p &lt; 0.084), and omentin (p &lt; 0.235) concentrations between SSE and HIIE. Similarly, no significant differences were seen between the sampled time points for either aerobic exercise condition. In conclusion, this study demonstrated there were no changes in adiponectin, leptin, or omentin concentrations when performing an acute bout of HIIE or SSE for 30 min, at 1 or 24 h post exercise. Future studies should seek to either increase the duration of the exercise bout or identify different adipokines to examine for patients experiencing moderate stages of CKD.

One bout of endurance exercise does not change gene expression or proliferation in a C26 colon carcinoma in immunocompetent mice

PurposeExercise typically reduces tumour growth, proliferation and improves outcomes. Many of these effects require exercise to change gene expression within a tumour, but whether exercise actually affects gene expression within a tumour has not been investigated yet. The aim of this study was, therefore, to find out whether one bout of endurance exercise alters gene expression and proliferation in a C26 carcinoma in immunocompetent mice.MethodsBALB/c were injected with C26 colon carcinoma cells. Once the tumours had formed, the mice either ran for 65 min with increasing intensity or rested before the tumour was dissected. The tumours were then analysed by RNA-Seq and stained for the proliferation marker KI67.ResultsOne bout of running for 65 min did not systematically change gene expression in C26 carcinomas of BALB/c mice when compared to BALB/c mice that were rested. However, when analysed for sex, the expression of 17, mostly skeletal muscle-related genes was higher in the samples of the female mice taken post-exercise. Further histological analysis showed that this signal likely comes from the presence of muscle fibres from the panniculus carnosus muscle inside the tumours. Also, we found no differences in the positivity for the proliferation marker KI67 in the control and exercise C26 carcinomas.ConclusionA bout of exercise did not systematically affect gene expression or proliferation in C26 carcinomas in immunocompetent BALB/c mice.

A Perspective on High-Intensity Interval Training for Performance and Health

Interval training is a simple concept that refers to repeated bouts of relatively hard work interspersed with recovery periods of easier work or rest. The method has been used by high-level athletes for over a century to improve performance in endurance-type sports and events such as middle- and long-distance running. The concept of interval training to improve health, including in a rehabilitative context or when practiced by individuals who are relatively inactive or deconditioned, has also been advanced for decades. An important issue that affects the interpretation and application of interval training is the lack of standardized terminology. This particularly relates to the classification of intensity. There is no common definition of the term “high-intensity interval training” (HIIT) despite its widespread use. We contend that in a performance context, HIIT can be characterized as intermittent exercise bouts performed above the heavy-intensity domain. This categorization of HIIT is primarily encompassed by the severe-intensity domain. It is demarcated by indicators that principally include the critical power or critical speed, or other indices, including the second lactate threshold, maximal lactate steady state, or lactate turnpoint. In a health context, we contend that HIIT can be characterized as intermittent exercise bouts performed above moderate intensity. This categorization of HIIT is primarily encompassed by the classification of vigorous intensity. It is demarcated by various indicators related to perceived exertion, oxygen uptake, or heart rate as defined in authoritative public health and exercise prescription guidelines. A particularly intense variant of HIIT commonly termed “sprint interval training” can be distinguished as repeated bouts performed with near-maximal to “all out” effort. This characterization coincides with the highest intensity classification identified in training zone models or exercise prescription guidelines, including the extreme-intensity domain, anaerobic speed reserve, or near-maximal to maximal intensity classification. HIIT is considered an essential training component for the enhancement of athletic performance, but the optimal intensity distribution and specific HIIT prescription for endurance athletes is unclear. HIIT is also a viable method to improve cardiorespiratory fitness and other health-related indices in people who are insufficiently active, including those with cardiometabolic diseases. Research is needed to clarify responses to different HIIT strategies using robust study designs that employ best practices. We offer a perspective on the topic of HIIT for performance and health, including a conceptual framework that builds on the work of others and outlines how the method can be defined and operationalized within each context.

Acute Effect of Dynamic and Gluteal Resistance Exercise Warm-up Protocols on Jump Landing Mechanics in College-Aged Females.

Rauseo, ML, Feairheller, DL, LaRoche, DP, and Cook, SB. Acute effect of dynamic and gluteal resistance exercise warm-up protocols on lower-extremity jump landing mechanics in college-aged females. J Strength Cond Res 38(2): 259-265, 2024-Inadequate neuromuscular control of the femur by the gluteal musculature is associated with noncontact and overuse injuries to the knee. Acute bouts of resistance exercises targeting the gluteal musculature can be prescribed as part of a warm-up protocol with the goal of improving subsequent neuromuscular control and performance. The purpose of this study was to determine the effect that a warm-up protocol including moderate-intensity gluteal resistance exercises (GRE) has on single leg jump landing biomechanics. Seventeen healthy, college-aged, recreationally active females (mean ± SD ; age = 21.4 ± 1.9 years; height = 166.9 ± 5.7 cm; body mass = 62.5 ± 7.4 kg) performed 3 single leg hop trials per leg after completing no warm-up (CON), a dynamic warm-up (DWU), and a dynamic warm-up with gluteal resistance exercises (DWU + GRE) across 3 laboratory visits. Lower extremity kinetic and kinematic variables were assessed during single leg hops from the point of initial foot contact to deepest knee flexion. Biomechanical differences between dominant and nondominant limb landings were also assessed. Dominant limb hip internal rotation angle after DWU + GRE (2.03 ± 9.92°) was significantly greater ( p ≤ 0.05) compared with CON (-3.36 ± 7.74°). Peak knee adduction moment (56.8%), peak knee flexion angle (5.7%), and peak knee external rotation angle (17.0%) were significantly greater ( p ≤ 0.017) in the dominant limb, compared with the nondominant limb, across warm-up protocols. The combined DWU + GRE warm-up protocol did not have a substantial impact on landing biomechanics. Clinicians prescribing GRE before activity should not expect significant changes in movement patterns after a single bout.

Integrative profiling of metabolome and transcriptome of skeletal muscle after acute exercise intervention in mice.

This study aims to explore the molecular regulatory mechanisms of acute exercise in the skeletal muscle of mice. Male C57BL/6 mice were randomly assigned to the control group, and the exercise group, which were sacrificed immediately after an acute bout of exercise. The study was conducted to investigate the metabolic and transcriptional profiling in the quadriceps muscles of mice. The results demonstrated the identification of 34 differentially expressed metabolites (DEMs), with 28 upregulated and 6 downregulated, between the two groups. Metabolic pathway analysis revealed that these DEMs were primarily enriched in several, including the citrate cycle, propanoate metabolism, and lysine degradation pathways. In addition, the results showed a total of 245 differentially expressed genes (DEGs), with 155 genes upregulated and 90 genes downregulated. KEGG analysis indicated that these DEGs were mainly enriched in various pathways such as ubiquitin mediated proteolysis and FoxO signaling pathway. Furthermore, the analysis revealed significant enrichment of DEMs and DEGs in signaling pathways such as protein digestion and absorption, ferroptosis signaling pathway. In summary, the identified multiple metabolic pathways and signaling pathways were involved in the exercise-induced physiological regulation of skeletal muscle, such as the TCA cycle, oxidative phosphorylation, protein digestion and absorption, the FoxO signaling pathway, ubiquitin mediated proteolysis, ferroptosis signaling pathway, and the upregulation of KLF-15, FoxO1, MAFbx, and MuRF1 expression could play a critical role in enhancing skeletal muscle proteolysis.

SAT042 Impact Of Aerobic Exercise On The Circulating Endothelial Progenitor Cells And Inflammation Markers In Type 1 Diabetes

Abstract Disclosure: C.K. Maraschin: None. P.M. Bock: None. R.B. Monteiro: None. A. Alegretti: None. P.L. Lopes: None. L.P. Santos: None. L. Helal: None. R. Moraes: None. D.U. de Moraes: None. B.D. Schaan: None. The circulating levels of endothelial progenitor cells (EPCs) is a marker of endothelial dysfunction in many chronic diseases, including diabetes mellitus. Increasing the amount of circulating EPCs through exercise may be a viable strategy for improving endothelial function. However, differences in EPC levels between individuals with and without diabetes and the responses of EPCs to exercise sessions were not previously studied. We sought to determine the number of circulating EPCs by flow cytometry in subjects with or without type 1 diabetes (T1DM), and to elucidate the independent or combined responses of EPC populations and inflammatory markers in response to one bout of intense aerobic exercise. This was a non-randomized controlled trial. Fifteen adult males, ages 18–65, with T1DM were included. Patients with high glycemia in the morning of the study or with chronic diabetic complications that made it difficult to perform the protocol were excluded. Fifteen healthy, non-obese, non-smoking individuals were recruited as controls. All included subjects underwent an aerobic exercise session on a cycle ergometer for 30 minutes at 60% of the predetermined peak heart rate. Blood samples were collected to evaluate plasma glucose levels, glycated hemoglobin (HbA1c), total and HDL cholesterol, tumor necrosis factor alpha (TNFa), interleukin 6 (IL-6), and EPCs (CD45dim/CD34+/KDR+) before and after the exercise session. Individuals with T1DM presented higher fasting plasma glucose (197.3 ± 90.0 mg/dL vs. 88 ± 11.2 mg/dL, p &amp;lt; 0.01) and HbA1c levels (7.9 ± 1.5 vs. 5.0 ± 0.3%, p &amp;lt; 0.01), while peak VO2 was higher in controls (37.6 ± 8.4 vs. 29.1 ± 10.9 mL.kg-1.min-1, p = 0.03). A complete blood count analysis showed increases in white blood cells [0.8 (0.1, 1.4) and 1.0 (0.4, 1.6) x103/µL, p &amp;lt; 0.001] and neutrophils [0.9 (0.3, 1.4) and 0.9 (0.3, 1.4) x103/µL, p &amp;lt; 0.001] in both groups after exercise. There was no difference within and between groups for EPCs before and after the aerobic exercise session - delta 0.02 (-0.04, 0.08) among controls and 0.00 (-0.01, 0.01) among individuals with T1DM]. No difference was observed in the levels of TNF-α among controls [210.2 (142.1 - 401.2); 191.3 (136.4 - 350.5) pg/mL] and individuals with T1DM [463.8 (201.4 - 4306.0); 482.7 (143.8 – 4304.3) pg/mL], before and 60 minutes after the exercise session, respectively. The IL-6 did not show any difference in controls [148.2 (147.5 – 148.6); 148.2 (147.7 – 148.6) pg/mL] and in those with T1DM [147.2 (145.9 – 147.7); 147.2 (146.8 – 147.8) pg/mL], before and 60 minutes after exercise, respectively. Patients with T1DM and healthy controls did not show a different response on EPCs levels after an acute session of aerobic exercise, most likely because they do not have a chronic inflammatory state. Hence, our study suggests that aerobic exercise (peak of 60% VO2) has the same effect on endothelial function in patients with or without T1DM. Presentation: Saturday, June 17, 2023

Effects of single and multiple bouts of eccentric exercise on immune responses to HSV-gD1 DNA vaccination in mice

Abstract DNA vaccines comprise one modality of novel vaccination techniques. DNA vaccines employ intramuscular injection of DNA that codes for specific antigens from a pathogen. Prolonged eccentric endurance exercise can stimulate immune responses, possibly by increasing inflammatory mediators. This study aimed to determine the effects of one or three sessions of downhill running on the effectiveness of Herpes simplex virus type I glycoprotein D (HSV-gD1) DNA vaccination. Mice without or with one and three sessions of downhill running were vaccinated intramuscularly with the DNA vaccine or the empty vector. Cellular immune responses were assessed using an in vitro assay of lymphocyte proliferation in response to recall antigens. Also, a virus neutralisation test was used to determine the levels of neutralising antibodies in serum samples. In addition, Th1 and Th2 immune responses, and the ratio of the Th1/Th2 is considered an indicator of immune responses to infection in the current study. Multiple bouts of downhill running increased humoral immune responses after immunisation, also although Th2 immune responses decreased, lymphocyte proliferation and Th1/Th2 ratio immune responses increased following the viral challenge compared to the other groups. In addition, the timing of the 3-session exercise regimen plus DNA vaccination immediately following the last exercise session, as opposed to DNA vaccination 48 h before a single session of exercise, may account for the greater efficacy of DNA vaccination in the multiple bouts of the intensive exercise group. These findings indicate that short-term repeated bouts of eccentric endurance exercise have increased immune responses to intramuscular DNA-based vaccines.

The effect of physical exercise on anticancer immunity.

Regular physical activity is associated with lower cancer incidence and mortality, as well as with a lower rate of tumour recurrence. The epidemiological evidence is supported by preclinical studies in animal models showing that regular exercise delays the progression of cancer, including highly aggressive malignancies. Although the mechanisms underlying the antitumorigenic effects of exercise remain to be defined, an improvement in cancer immunosurveillance is likely important, with different immune cell subtypes stimulated by exercise to infiltrate tumours. There is also evidence that immune cells from blood collected after an exercise bout could be used as adoptive cell therapy for cancer. In this Perspective, we address the importance of muscular activity for maintaining a healthy immune system and discuss the effects of a single bout of exercise (that is, 'acute' exercise) and those of 'regular' exercise (that is, repeated bouts) on anticancer immunity, including tumour infiltrates. We also address the postulated mechanisms and the clinical implications of this emerging area of research.

Protein dose requirements to maximize skeletal muscle protein synthesis after repeated bouts of resistance exercise in young trained women.

Studies examining the effect of protein (PRO) feeding on post resistance exercise (RE) muscle protein synthesis (MPS) have primarily been performed in men, and little evidence is available regarding the quantity of PRO required to maximally stimulate MPS in trained women following repeated bouts of RE. We therefore quantified acute (4 h and 8 h) and extended (24 h) effects of two bouts of resistance exercise, alongside protein-feeding, in women, and the PRO requirement to maximize MPS. Twenty-four RE trained women (26.6 ± 0.7 years, mean ± SEM) performed two bouts of whole-body RE (3 × 8 repetitions/maneuver at 75% 1-repetition maximum) 4 h apart, with post-exercise ingestion of 15 g, 30 g, or 60 g whey PRO (n = 8/group). Saliva, venous blood, and a vastus lateralis muscle biopsy were taken at 0 h, 4 h, 8 h, and 24 h post-exercise. Plasma leucine and branched chain amino acids were quantified using gas chromatography mass spectrometry (GC-MS) after ingestion of D2 O. Fifteen grams PRO did not alter plasma leucine concentration or myofibrillar synthetic rate (MyoFSR). Thirty and sixty grams PRO increased plasma leucine concentration above baseline (105.5 ± 5.3 μM; 120.2 ± 7.4 μM, respectively) at 4 h (151.5 ± 8.2 μM, p < 0.01; 224.8 ± 16.0 μM, p < 0.001, respectively) and 8 h (176.0 ± 7.3 μM, p < 0.001; 281.7 ± 21.6 μM, p < 0.001, respectively). Ingestion of 30 g PRO increased MyoFSR above baseline (0.068 ± 0.005%/h) from 0 to 4 h (0.140 ± 0.021%/h, p < 0.05), 0 to 8 h (0.121 ± 0.012%/h, p < 0.001), and 0 to 24 h (0.099 ± 0.011%/h, p < 0.01). Ingestion of 60 g PRO increased MyoFSR above baseline (0.063 ± 0.003%/h) from 0 to 4 h (0.109 ± 0.011%/h, p < 0.01), 0 to 8 h (0.093 ± 0.008%/h, p < 0.01), and 0 to 24 h (0.086 ± 0.006%/h, p < 0.01). Post-exercise ingestion of 30 g or 60 g PRO, but not 15 g, acutely increased MyoFSR following two consecutive bouts of RE and extended the anabolic window over 24 h. There was no difference between the 30 g and 60 g responses.

Sounds hard: Prosodic features reflect effort level and related affective states during exercise

Bouts of exercise have a substantial affective influence, which can impact performance and adherence through training programs. Yet, both the level of effort exertion and affective state during exercise are hard to monitor without the use of questionnaires, which suffer from certain limitations. Here, we examined whether prosodic features, prominent characteristics of human expression, reflect the effort level and its related affect during bouts of exercise. We extracted prosodic features from verbal affective valence ratings recorded in a previously published study (n = 20; 10 women; nobs = 2428) of resistance exercises performed by trained participants until task failure. We found that the mean and SD of the pitch predicted effort-related affective valence and proximity to task failure in the two subsets of the data, and in three separate bouts of exercise. These results imply that mean pitch elevation and the decrease of the SD of the pitch during effort exertion may serve as a signal of distress as task difficulty increases. The consistency of the findings across different exercises suggests that the mean and the SD of the pitch may be used to monitor physical effort and affect in various settings and help uncover the nature of physical effort in its different manifestations.

Effect of acute handgrip and aerobic exercise on wasted pressure effort and arterial wave reflections in healthy aging.

Aging increases arterial stiffness and wave reflections that augment left ventricular wasted pressure effort (WPE). A single bout of exercise may be effective at acutely reducing WPE via reductions in arterial wave reflections. In young adults (YA) acute aerobic exercise decreases, whereas handgrip increases, wave reflections. Whether acute exercise mitigates or exacerbates WPE and arterial wave reflection in healthy aging warrants further examination. The purpose of this study was to determine if there are age-related differences in WPE and wave reflection during acute handgrip and aerobic exercise. When compared with baseline, WPE increased substantially in older adults (OA) during handgrip (5,219 ± 2,396 vs. 7,019 ± 2,888 mmHg·ms, P < 0.001). When compared with baseline, there was a robust reduction in WPE in OA during moderate-intensity aerobic exercise (5,428 ± 2,084 vs. 3,290 ± 1,537 mmHg·ms, P < 0.001), despite absolute WPE remaining higher in OA compared with YA during moderate-intensity aerobic exercise (OA 3,290 ± 1,537 vs. YA 1,188 ± 962 mmHg·ms, P < 0.001). There was no change in wave reflection timing indexed to ejection duration in OA during handgrip (40 ± 6 vs. 38 ± 4%, P = 0.41) or moderate-intensity aerobic exercise (40 ± 5 vs. 42 ± 8%, P = 0.99). Conversely, there was an earlier return of wave reflection in YA during handgrip (60 ± 11 vs. 52 ± 6%, P < 0.001) and moderate-intensity aerobic exercise (59 ± 7 vs. 51 ± 9%, P < 0.001). Changes in stroke volume were not different between groups during handgrip (P = 0.08) or aerobic exercise (P = 0.47). The greater increase in WPE during handgrip and decrease in WPE during aerobic exercise suggest that aortic hemodynamic responses to acute exercise are exaggerated with healthy aging without affecting stroke volume.NEW & NOTEWORTHY We demonstrated that acute aerobic exercise attenuated, whereas handgrip augmented, left ventricular hemodynamic load from wave reflections more in healthy older (OA) compared with young adults (YA) without altering stroke volume. These findings suggest an exaggerated aortic hemodynamic response to acute exercise perturbations with aging. They also highlight the importance of considering exercise modality when examining aortic hemodynamic responses to acute exercise in older adults.

The Biological Basis of Sex Differences in Athletic Performance: Consensus Statement for the American College of Sports Medicine

ABSTRACT Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%–30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, but remains low in females. The primary goal of this consensus statement is to provide the latest scientific knowledge and mechanisms for the sex differences in athletic performance. This review highlights the differences in anatomy and physiology between males and females that are primary determinants of the sex differences in athletic performance and in response to exercise training, and the role of sex steroid hormones (particularly testosterone and estradiol). We also identify historical and nonphysiological factors that influence the sex differences in performance. Finally, we identify gaps in the knowledge of sex differences in athletic performance and the underlying mechanisms, providing substantial opportunities for high-impact studies. A major step toward closing the knowledge gap is to include more and equitable numbers of women to that of men in mechanistic studies that determine any of the sex differences in response to an acute bout of exercise, exercise training, and athletic performance.

In-ear integrated sensor array for the continuous monitoring of brain activity and of lactate in sweat

Owing to the proximity of the ear canal to the central nervous system, in-ear electrophysiological systems can be used to unobtrusively monitor brain states. Here, by taking advantage of the ear’s exocrine sweat glands, we describe an in-ear integrated array of electrochemical and electrophysiological sensors placed on a flexible substrate surrounding a user-generic earphone for the simultaneous monitoring of lactate concentration and brain states via electroencephalography, electrooculography and electrodermal activity. In volunteers performing an acute bout of exercise, the device detected elevated lactate levels in sweat concurrently with the modulation of brain activity across all electroencephalography frequency bands. Simultaneous and continuous unobtrusive in-ear monitoring of metabolic biomarkers and brain electrophysiology may allow for the discovery of dynamic and synergetic interactions between brain and body biomarkers in real-world settings for long-term health monitoring or for the detection or monitoring of neurodegenerative diseases.

The effect of chronic exercise training and acute exercise on power spectral analysis of heart rate variability.

Moderate to vigorous physical activity performed regularly is cardioprotective and reduces all-cause mortality, concomitant with increased resting heart rate variability (HRV). However, there are contradictory reports regarding the effects of chronic and acute exercise on nocturnal HRV in those performing exercise well-beyond physical activity guidelines. Therefore, the purpose of this study was to compare the power spectral analysis components of HRV in middle-aged endurance athletes (EA) and recreationally active individuals (REC) and explore acute exercise effects in EA. A total of 119 EA (52, 49-57 years) and 32 REC (56, 52-60 years) were recruited to complete 24h Holter monitoring (GE SEER 1000) in the absence of exercise. Fifty one EA (52, 49-57 years) then underwent 24h Holter monitoring following an intense bout of endurance exercise. Power spectral HRV analysis was completed hourly and averaged to quantify morning (1000-1200h), evening (1900-2100h), and nocturnal (0200-0400h) HRV. EA had greater very low frequency (VLF) and low frequency (LF) (both p< 0.001) compared to REC. LF/high frequency (HF) was greater in EA at 0200-0400h (p=0.04). Among all participants, the change in HR and HF from 1000-1200 to 0200-0400h was negatively correlated (r=-0.47, p< 0.001). Following acute exercise in EA, only nocturnal HRV was assessed. VLF (p< 0.001) and HF (p=0.008) decreased, while LF/HF increased (p=0.02). These results suggest that in EA, both long-term and acute exercises increase nocturnal sympathovagal activity through an increase in LF and decrease in HF, respectively. Further work is required to understand the mechanism underlying reduced nocturnal HRV in middle-aged EA and the long-term health implications.

Aortic pulse wave comparison between controls and triathletes in baseline conditions and in response to acute maximum exercise

To determine the effects of intense training on aortic pulse wave variables and hemodynamic parameters at baseline and at recovery from maximal exercise testing (MaxET) in triathletes compared with sedentary individuals. In this prospective and experimental study, 21 triathletes and 21 sedentary individuals were recruited and evaluated prior and two minutes after the MaxET using the Mobil-O-Graph®, which estimates the aortic pulse wave from the brachial artery pressure. The augmentation index (AIx@75) was lower in triathletes after the MaxET compared to control group (16.34 ± 5.95 vs. 23.5 ± 8.53%, p = 0.001), while the pulse wave velocity (PWV) was similar between groups. The heart rate was significantly lower at baseline and after MaxET in triathletes group (55.70 ± 8.95 bpm 91.49 ± 11.39 bpm) compared with control group (62.11 ± 6.70 bpm; 102.08 ± 10.85 bpm). The stroke volume was significantly higher at baseline (96.08 ± 13.96 ml; 86.17 ± 11.24 ml) and after MaxET in triathletes group (69.15 ± 6.51 ml, 58.38 ± 6.99 ml) compared with control group. Triathetes show lower value of AIx@75 after MaxET in comparison with the control group. AIx@75, in addition to being an indirect measure of arterial stiffness, is also a measure of left ventricular afterload. Thus, the lower AIx@75 in triathletes may be due to their lower left ventricular afterload, lower myocardial oxygen demand, and greater coronary perfusion than sedentary individuals. The hemodynamic changes observed in triathletes at rest and during an acute exercise bout are distinctive characteristics of aerobic physical training.