Physiologia最新文献

{"title":"Reliability of the 15-s Maximal Lactate Accumulation Rate (VLamax) Test for Cycling","authors":"Christopher R. Harnish, Thomas C. Swensen, Deborah King","doi":"10.3390/physiologia3040040","DOIUrl":"https://doi.org/10.3390/physiologia3040040","url":null,"abstract":"Background: The purpose of this study is to ascertain the reliability of two 15-s sprint cycling tests in men and women to estimate the maximum lactate accumulation rate (VLamax). Methods: Eighteen men and twelve women completed two sprint sessions over 1 week. A 10 min warm-up preceded the obtaining of a 3 µL blood lactate (BLC) sample, after which a 15 s sprint was completed; cyclists then rested passively while multiple lactate samples were taken until the levels peaked. Trial differences and reliability across trials were analyzed using a paired-sample t-test, Pearson’s correlation, Intraclass correlation (ICC), and Bland–Altman analysis with α = 0.05 for all tests; data are reported as mean ± sd. Results: Power (W) was similar across trials (773.0 ± 143.5 vs. 758.2 ± 127.4; p = 0.333) and the coefficient of variation (CV) of 4.7%. VLamax (mM·L−1·s−1) was similar (0.673 ± 0.024 vs. 0.635 ± 0.237; p = 0.280), but only moderately reliable across trials with CV, ICC, and R values of 18.6%, 0.661, and 0.67, respectively. Pre-BLC and peak BLC CV were 45.6 and 23.3%, respectively. Conclusions: A 15 s VLamax cycling sprint is moderately reliable, possibly affected both by the lactate measurement and other variables used in the calculation. More research may offer ways to improve reliability.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"55 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135370967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of No-Till System with or without Cover Crops on Stomata Sensitivity of Glyphosate-Tolerant Soybeans to Vapor Pressure Deficit","authors":"Jérôme Bernier Brillon, Matthieu Moingt, Marc Lucotte","doi":"10.3390/physiologia3040039","DOIUrl":"https://doi.org/10.3390/physiologia3040039","url":null,"abstract":"Soybeans are vulnerable to drought and temperature increases potentially induced by climate change. Hydraulic dysfunction and stomatal closure to avoid excessive transpiration are the main problems caused by drought. The vulnerability of soybeans to drought will depend on the intensity and duration of water stress. The purpose of this study was to determine if the use of cover crops (CCs) can influence the gas exchange potential of glyphosate-tolerant soybeans when the vapor pressure deficit (Vpd) increases. This two-year study was conducted in an open experimental field comprising direct seeding plots with or without CCs. Stomatal conductance (Gs) was measured five times on the same identified leaves following glyphosate-based herbicide application. These leaves were then collected in order to observe the stomata and foliar traits with a scanning electron microscope. The Vpd was calculated concomitantly to Gs measurements at the leaf surface. The results suggest that the use of CCs promotes phenotypic change in soybean leaves (more elaborate venation and a higher abaxial stomatal density), which in turn may enhance their tolerance to drier conditions. In 2019, Gs could be up to 29% higher in plots with CCs compared to those without CCs with similar Vpd values. This study shows that the benefits of using CCs can be observed via the morphological development strategies of the crop plants and their higher tolerance to drought.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"33 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135111345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of Acute Bouts of Aerobic Exercise on Adipokine Concentrations in Individuals with Moderate Stages of Chronic Kidney Disease","authors":"Tomas J. Chapman-Lopez, James Kyle Taylor, Ricardo Torres, Dylan Wilburn, LesLee K. Funderburk, Dale C. Allison, Jeffrey S. Forsse","doi":"10.3390/physiologia3040038","DOIUrl":"https://doi.org/10.3390/physiologia3040038","url":null,"abstract":"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 < 0.05). There were no significant differences in adiponectin (p < 0.353), leptin (p < 0.084), and omentin (p < 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.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135943947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravitational Ischemia in the Brain: How Interfering with Its Release May Predispose to Either Alzheimer’s- or Parkinson’s-like Illness, Treatable with Hyperbaric Oxygen","authors":"J. Howard Jaster, Giulia Ottaviani","doi":"10.3390/physiologia3040037","DOIUrl":"https://doi.org/10.3390/physiologia3040037","url":null,"abstract":"The physiological mechanisms for releasing and resolving gravitational ischemia in the brain, and their susceptibility to malfunction, may play an important role in a variety of neurological illnesses. An astronaut on a space walk in a micro-gravity environment may be susceptible to neuro-ocular symptoms associated with unopposed gravity-resistance mechanisms for partially preventing gravitational ischemia in the brain, and for attenuating its impact—mechanisms which may be required for normal brain physiology on Earth. Astronauts on the International Space Station typically breathe a mixture of gasses similar in composition to what they breathed on Earth, following the 1967 death of three astronauts, including Ed White, by fire on the Apollo 1 spacecraft, which was carrying 100% oxygen. For the last decade, astronauts have been studied extensively by flight physicians regarding the commonly experienced symptoms of VIIP, or ‘visual impairment and intracranial pressure’ syndrome. In this paper, we compare VIIP syndrome to the neuro-ocular and Parkinson’s-like symptoms which occurred during and after the 1918–1919 influenza pandemic. The common denominator may be gravitational ischemia in the brain, and the mirror-imaging failed mechanisms for its release (in influenza) versus unopposed gravity-resistance mechanisms (in astronauts). Some research has suggested that astronauts may benefit from breathing oxygen concentrations somewhat higher than 20%, and under slightly elevated pressure. These may possibly prevent maladaptive mechanisms leading to Alzheimer’s- or Parkinson’s-like illness by compensating for impaired mechanisms for releasing and resolving gravitational ischemia in the brain.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135591378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"StartXFit—Nine Months of CrossFit® Intervention Enhance Cardiorespiratory Fitness and Well-Being in CrossFit Beginners","authors":"Jennifer Schlie, Tom Brandt, Annette Schmidt","doi":"10.3390/physiologia3040036","DOIUrl":"https://doi.org/10.3390/physiologia3040036","url":null,"abstract":"Insufficient physical activity (PA) is associated with low cardiorespiratory fitness, which favors cardiovascular and other noncommunicable diseases. Additionally, it evidentially affects mental health. Considering the WHO PA guidelines, CrossFit® represents a versatile exercise program that combines aerobic and resistance training with mobility and could help reduce disease incidences among sedentary people. Yet, long-term CrossFit research is sparse. We conducted a nine-month intervention (≥2 CrossFit workouts/week) in 16 beginners (14 males, 35 ± 6.8 years, 180 ± 8.6 cm, 85. 5 ± 19.1 kg). As a primary endpoint, VO2max was assessed at baseline, four, and nine months. A repeated-measures ANOVA and Pearson correlation were conducted. Well-being was investigated by the WHO-5 Index pre- and post-intervention. For exploratory purposes, body composition and heart rate recovery (HRR) were tracked. In a second step, all males were categorized into two groups based on body fat percentage and analyzed by repeated measures ANOVA again. The main outcome was an 11.5% VO2max improvement with a large effect (p < 0.01, ηp2 = 0.27). Strong negative correlations between baseline VO2max and its progression after nine months (p = 0.006, r = −0.654) were found. Well-being increased by 8.7% (p = 0.024, d = 0.51). HRR improved both at 1 min (p < 0.05, ηp2 = 0.34) and at 5 min (p < 0.05, ηp2 = 0.27) post-exercise. Resting metabolic rate increased by 2.2% (p = 0.042). Analysis by group revealed improved HRR at 1 min (p < 0.05, ηp2 = 0.62) only for the “high body fat” group. This study reveals the potential of CrossFit to enhance physiological and psychological health in beginners. For more robust results, larger sample sizes with a higher proportion of women are needed.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135719178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weight Loss and Competition Weight Comparing Male and Female Mixed Martial Artists Competing in the Ultimate Fighting Championship’s (UFC) Flyweight Division","authors":"Corey A. Peacock, Justin Braun, Gabriel J. Sanders, Anthony Ricci, Charles Stull, Duncan French, Cassandra Evans, Jose Antonio","doi":"10.3390/physiologia3040035","DOIUrl":"https://doi.org/10.3390/physiologia3040035","url":null,"abstract":"Background: Although there is much literature demonstrating weight changes in professional mixed martial arts (MMA) athletes, there is minimal data comparing male and female MMA athletes. Therefore, the purpose of the current study was to compare weight changes between professional male and female MMA athletes leading up to competition. Methods: One hundred and three professional flyweight MMA athletes competing for the Ultimate Fighting Championship (UFC) were used for the study. Weight was obtained at multiple time points leading up to the competition. Two-way ANOVAs and post hoc t-tests were used, and significance was set at p ≤ 0.05. Results: ANOVA revealed there was a significant main effect of condition for weight changes (p < 0.001) and a significant main effect of sex on weight changes (p = 0.002) prior to competition. Post hoc analysis revealed that males lost more weight prior to the official weigh-in and gained more weight prior to competition when compared to females (p ≤ 0.05). Conclusion: MMA athletes lose weight prior to the official weigh-in and gain weight prior to competition. Moreover, male MMA athletes lose more weight prior to and gain more weight after when compared to female MMA athletes competing in the UFC’s flyweight division.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135816013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring Adherence to Moderate to High-Intensity Exercises in Patients with Fibromyalgia: The Role of Physiological and Psychological Factors—A Narrative Literature Review","authors":"Caio V. M. Sarmento, Zhaoyang Liu, Irina V. Smirnova, Wen Liu","doi":"10.3390/physiologia3030034","DOIUrl":"https://doi.org/10.3390/physiologia3030034","url":null,"abstract":"Fibromyalgia (FM) is a chronic condition characterized by widespread chronic pain, muscle tenderness, chronic fatigue, and sleep disturbances. Treatment of FM focuses on the management of symptoms, often using medications, cognitive behavioral therapy, or moderate-to-high-intensity exercises (MHIE). MHIE is highly recommended by the current guidelines from the American College of Sports Medicine and the American Heart Association for people with FM to decrease comorbidities due to sedentary lifestyles. MHIE has also been shown to improve FM symptoms in individuals who can tolerate MHIE. However, individuals with FM present with one of the poorest adherences to MHIE. Most individuals with FM report symptoms worsening at the beginning of an MHIE intervention program. Objectives: This literature review aims to estimate the adherence to MHIE using dropout and compliance rates in individuals with FM who participated in studies that applied MHIE as an intervention and to examine possible reasons for high dropout rates and low compliance with MHIE programs, including psychological and physiological factors. Understanding the scope of potential dropout and compliance rates to MHIE intervention and factors that impact MHIE adherence in people with FM may help researchers and clinicians better design clinical trial studies and develop tailored exercise interventions according to individual patient characteristics. Conclusion: FM is a multi-faceted syndrome that can vary significantly in its presentation from person to person due to the complex duality of psychological and physiological factors. Consequently, clinicians should consider both components when prescribing exercises to FM patients.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136236431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing Knowledge of the Bio-Cultural Complexities of Low Energy Availability: The Value of Mixed-Methods Approaches","authors":"Katherine L. Schofield, Holly Thorpe, Stacy T. Sims","doi":"10.3390/physiologia3030033","DOIUrl":"https://doi.org/10.3390/physiologia3030033","url":null,"abstract":"Low energy availability (LEA) is a complex health condition that most commonly affects female athletes. Research on LEA is weighted to quantitative approaches, and few studies have employed qualitative methods to understand the development of LEA. Current research fails to understand the complexity of LEA by largely operating within isolated research paradigms. This paper aims to demonstrate the value of integrating a mixed-methods research approach to understand the influence of sporting cultures on the physiological experiences of female athletes with LEA. The mixed-methods approach implemented the use of physiological (quantitative) and socio-psychological (qualitative) data obtained from elite female athletes in three sports: triathlons and running, (n = 11), rugby sevens (n = 9), and track cycling (n = 10). The physiological data consisted of energy availability, haematological analysis, bone health, and body composition. The socio-psychological data consisted of individual semi-structured interviews with topics covering nutrition, body image, the impact of the sporting environment, and experience with LEA. The interview data were thematically analysed. By bringing qualitative and quantitative data together, this paper illustrates the complex relationship between sporting culture and the physiology of LEA. First, endurance athletes categorised as having an LEA showed a positive correlation between the relative energy intake (EI) and serum ferritin, with the interviews revealing a focus on a low body weight and reducing the EI. Second, the interviews with the rugby players showed a strong but hierarchical team culture, with the experienced players monitoring and controlling the EI of novice players. Third, among the cyclists, the EI was reduced in those categorised as having an LEA, with the interviews revealing a coach–athlete power relationship impacting dietary behaviours. To conclude, this paper demonstrates how mixed methods are important for capturing how different sporting cultures impact athletes’ socio-psychological and physiological experiences of LEA.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134912874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Assessment of Viscoelastic Skeletal Muscle Properties in Chronic Kidney Disease: Association with Physical Functioning","authors":"Thomas J. Wilkinson, Ellie F. Gore, Luke A. Baker, Alice C. Smith","doi":"10.3390/physiologia3030032","DOIUrl":"https://doi.org/10.3390/physiologia3030032","url":null,"abstract":"Chronic kidney disease (CKD) is characterised by poor physical function. Mechanical muscle properties such as tone, elasticity, and stiffness influence the functional state of the muscle. Measuring these muscle mechanical properties is difficult and data on CKD are sparse. Using a novel myotonometer device, the aims of this study were to compare the viscoelastic muscle properties in CKD patients with previously reported data and to explore the association with muscle function. Non-dialysis-dependent CKD participants were recruited into a cross-sectional study conducted between 2018 and 2020. Muscle properties (tone, stiffness, elasticity) were assessed using a myotonometer (MyotonPRO). Muscle function was assessed using physical performance tests (sit-to-stand 5 and 60, timed up and go, short physical performance battery, gait speed, incremental shuttle walk, postural sway). General linear regression models were used to explore the association between muscle properties and physical function. Thirty-nine participants were included (age 64.2 (SD: 10.4) years; 51% male; eGFR 40.9 (SD: 20.0) mL/min/1.73 m2). Participants with CKD had reduced muscle tone, stiffness, and elasticity compared to previously reported studies. Muscle tone (B = −0.567, p = 0.003) and muscle stiffness (B = −0.368, p = 0.071) were greater in males than females. Increased BMI was associated with lower muscle tone (B = −0.528, p = 0.002) and muscle stiffness (B = −0.577, p = 0.002). No meaningful nor consistent associations were found between these properties and measures of muscle function and physical performance. In conclusion, using a novel handheld myotonometer, this study found that CKD patients exhibit a reduction in muscle tone, stiffness, and elasticity. In a passive state, these viscoelastic muscle properties showed no consistent associations with physical performance.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134912121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Observation of the Vitamin D Status in Highly Trained Adolescent Swimmers during the UK Autumn and Winter Months","authors":"J. W. Newbury, Meghan A. Brown, Matthew Cole, A. Kelly, Lewis A. Gough","doi":"10.3390/physiologia3030031","DOIUrl":"https://doi.org/10.3390/physiologia3030031","url":null,"abstract":"The purpose of this research was two-fold: (a) to observe whether highly trained adolescent swimmers abide to vitamin D supplement recommendations; and (b) to monitor changes in circulating 25-hydroxyvitamin D (25(OH)D) that occur between the autumn and winter months. Twenty swimmers (age: 17 ± 2 years) from a UK high-performance swimming club volunteered to complete two blood spot cards to determine their 25(OH)D concentration: the first in an autumn training phase (October) and the second during winter training (January). All swimmers were advised to consume vitamin D3 supplements across the assessment period; however, only 50% of swimmers adhered to this recommendation. Resultantly, a winter decline in 25(OH)D was observed in non-supplementing swimmers (79.6 ± 25.2 to 52.6 ± 15.1 nmol·L−1, p = 0.005), with swimmers either displaying an ‘insufficient’ (60%) or ‘deficient’ (40%) vitamin D status. In comparison, a greater maintenance of 25(OH)D occurred in supplementing swimmers (92.0 ± 25.5 to 97.2 ± 38.3 nmol·L−1, p = 0.544), although variable outcomes occurred at the individual level (four increased, three maintained, three declined). These findings highlight the possible risks of vitamin D insufficiency during the winter for swimmers in the UK, possibly requiring standardised supplement practices. Moreover, alternative educational strategies may be required for swimmers to transfer knowledge to practice in order to improve supplement adherence in future.","PeriodicalId":93484,"journal":{"name":"Physiologia","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42249986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}