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1.
Eur J Appl Physiol ; 2024 May 31.
Article in English | MEDLINE | ID: mdl-38819659

ABSTRACT

PURPOSE: The involvement of central command in central hemodynamic regulation during exercise is relatively well-known, although its contribution to peripheral hemodynamics at the onset of low-intensity contractions is debated. This study sought to examine central and peripheral hemodynamics during electrically-evoked muscle contractions (without central command) and voluntary muscle activity (with central command). METHODS: Cyclic quadriceps isometric contractions (1 every second), either electrically-evoked (ES; 200 ms trains composed of 20 square waves) or performed voluntarily (VC), were executed by 10 healthy males (26 ± 3 years). In both trials, matched for force output, peripheral and central hemodynamics were analysed. RESULTS: At exercise onset, both ES and VC exhibited equal peaks of femoral blood flow (1276 ± 849 vs. 1117 ± 632 ml/min, p > 0.05) and vascular conductance (15 ± 11 vs. 13 ± 7 ml/min/mmHg, p > 0.05), respectively. Similar peaks of heart rate (86 ± 16 bpm vs. 85 ± 16 bpm), stroke volume (100 ± 20 vs. 99 ± 27 ml), cardiac output (8.2 ± 2.5 vs. 8.5 ± 2.1 L/min), and mean arterial pressure (113 ± 13 vs. 113 ± 3 mmHg), were recorded (all, p > 0.05). After ~ 50 s, all the variables drifted to lower values. Collectively, the hemodynamics showed equal responses. CONCLUSION: These results suggest a similar pathway for the initial (first 40 s) increase in central and peripheral hemodynamics. The parallel responses may suggest an initial minimal central command involvement during the onset of low-intensity contractions, likely associated with a neural drive activation delay or threshold.

2.
Physiol Rep ; 12(6): e15988, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38537943

ABSTRACT

The downward slope during the near-infrared spectroscopy (NIRS)-vascular occlusion test (NIRS-VOT) is purported as a simplified estimate of metabolism. Whether or not the NIRS-VOT exhibits sex- or limb-specificity or may be acutely altered remains to be elucidated. Thus, we investigated if there is limb- or sex specificity in tissue desaturation rates (DeO2) during a NIRS-VOT, and if acute dietary capsaicin may alter this estimate of muscle metabolism. Young healthy men (n = 25, 21 ± 4 years) and women (n = 20, 20 ± 1 years) ingested either placebo or capsaicin, in a counterbalanced, single-blind, crossover design after which a simplified NIRS-VOT was conducted to determine the DeO2 (%/s), as an estimate of oxidative muscle metabolism, in both the forearm (flexors) and thigh (vastus lateralis). There was a significant limb effect with the quadriceps having a greater DeO2 than the forearm (-2.31 ± 1.34 vs. -1.78 ± 1.22%/s, p = 0.007, ηp 2 = 0.19). There was a significant effect of sex on DeO2 (p = 0.005, ηp 2 = 0.203) with men exhibiting a lesser DeO2 than women (-1.73 ± 1.03 vs. -2.36 ± 1.32%/s, respectively). This manifested in significant interactions of limb*capsaicin (p = 0.001, ηp 2 = 0.26) as well as limb*capsaicin*sex on DeO2 (p = 0.013, ηp 2 = 0.16) being observed. Capsaicin does not clearly alter O2-dependent muscle metabolism, but there was apparent limb and sex specificity, interacting with capsaicin in this NIRS-derived assessment.


Subject(s)
Capsaicin , Vascular Diseases , Female , Humans , Male , Capsaicin/pharmacology , Muscle, Skeletal/metabolism , Oxygen Consumption/physiology , Single-Blind Method , Spectroscopy, Near-Infrared/methods , Vascular Diseases/metabolism
3.
Dis Aquat Organ ; 157: 95-106, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38546193

ABSTRACT

Parasitic sea lice (Copepoda: Caligidae) colonising marine salmonid (Salmoniformes: Salmonidae) aquaculture production facilities have been implicated as a possible pressure on wild salmon and sea trout populations. This investigation uses monitoring data from the mainland west coast and Western Isles of Scotland to estimate the association of the abundance of adult female Lepeophtheirus salmonis (Krøyer) colonising farmed Atlantic salmon Salmo salar L. with the occurrence of juvenile and mobile L. salmonis on wild sea trout, anadromous S. trutta L. The associations were evaluated using generalised linear mixed models incorporating farmed adult female salmon louse abundances which are temporally lagged relative to dependent wild trout values. The pattern of lags, which is consistent with time for L. salmonis development between egg and infective stage, was evaluated using model deviances. A significant positive association is identified between adult female L. salmonis abundance on farms and juvenile L. salmonis on wild trout. This association is consistent with a causal relationship in which increases in the number of L. salmonis copepodids originating from lice colonising farmed Atlantic salmon cause an increase of L. salmonis abundance on wild sea trout.


Subject(s)
Copepoda , Fish Diseases , Salmo salar , Animals , Female , Trout , Aquaculture , Scotland/epidemiology , Fish Diseases/epidemiology , Fish Diseases/parasitology
4.
Complement Ther Med ; 80: 103022, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38191033

ABSTRACT

Watching news broadcasts is known to elicit psychological stress. Conversely, the iconic painter Bob Ross (BR) has risen to pop culture status and amassed a following, as many find the messages and sounds of BR to be soothing and relaxing. Though, it has yet to be directly tested if such exposure can confer psychological or physiological benefit. The purpose of this study was to compare the effects of watching BR versus streaming news on markers of cardiovascular health and profile of mood states (POMS). It was hypothesized that watching BR would increase POMS scores and heart rate variability (HRV). It was also hypothesized that watching the news would increase blood pressure (BP), vascular stiffness (VS), and heart rate (HR). METHODS: In a randomized, controlled, crossover design, 18 young (21 ± 1 yrs, 9 female, 9 male) healthy participants (172.6 ± 9.9 cm, 69 ± 18 kg) were assessed for BP, VS, HR, HRV, and POMS before and after watching an episode of BR or the News matched for time (∼27 mins). RESULTS: A significant interaction effect on POMS scores were observed for, anxiety (p = 0.01), anger (p = 0.008), depression (p = 0.003), fatigue (p = 0.001), and confusion (p = 0.01) domains after watching BR. The LF/HF ratio, an HRV marker of sympathovagal balance, was significantly lower after watching BR (p = 0.04). There were no significant time, condition, or interaction effects on systolic BP, mean arterial pressure, and diastolic BP. CONCLUSION: The "Bob Ross Effect" reduces overall mood disturbance, though appears to exert little influence on the cardiovascular system in this acute paradigm.


Subject(s)
Anxiety , Heart , Female , Humans , Male , Blood Pressure , Heart Rate/physiology , Stress, Psychological , Cross-Over Studies , Young Adult
5.
Article in English | MEDLINE | ID: mdl-38131715

ABSTRACT

The public-health restrictions (e.g., remote learning, restricted access to facilities and dining halls) put in place by colleges to reduce the spread of COVID-19 resulted in forced isolation and modifications to health-related behaviors. The restrictions and uncertainty associated with COVID-19 may have exacerbated the challenges of meeting exercise recommendations and mental-health concerns. The purpose of this study was to assess the impact of restrictions on students' exercise habits and their levels of anxiety, stress, and depression. Five-hundred and forty students completed a 29-question survey on individual demographics, living arrangements, exercise, sleep, diet, and mental health. Significant changes in weekly days of exercise and intensity were reported. Increases in anxiety, stress, and depression were reported. The two most frequently reported changes in exercise behavior were an increase in minutes of aerobic training (5%) and a combination of reduced minutes of aerobic and resistance training (3.9%), which could be reflective of an individual's ability and/or desire to maintain exercise behavior during the restrictions. Alternatively, for those students who reduced their exercise habits, aerobic training (11%) was the mode that suffered the most. Demographic factors such as ethnicity, regional residence, and gender were found to have significant effects on stress, anxiety, and depression. Amidst pandemics and future health emergencies, colleges should prioritize establishing opportunities for students to exercise, helping them meet physical activity recommendations and combat mental-health issues.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Mental Health , Self Report , SARS-CoV-2 , Anxiety/epidemiology , Anxiety/psychology , Exercise/psychology , Students/psychology , Depression/epidemiology , Depression/psychology
6.
Article in English | MEDLINE | ID: mdl-37998306

ABSTRACT

Despite great strides in the development of contraceptive technologies, the United States has one of the highest teen pregnancy rates in the world. Religion and associated values may shape the sexual health behaviors of college students, as prior studies have aimed to determine how social factors may influence the use of contraception amongst college students. Thus, we sought to examine the differences in current contraceptive methods and the age of first contraceptive usage among sexually active female college students with different religious affiliations and strengths of religiosity. It was hypothesized that there would be no difference in current contraceptive methods among different religious affiliations and strengths of religions and that there would be a difference in the age of first contraceptive usage among different religious affiliations and strengths of religiosity. Two hundred and twenty-four college-aged females completed a 20-question survey about sexual health and religious practices. Chi-squared tests were implemented to determine the frequencies of responses across religious affiliations and strengths of religiosity. Significant differences in the frequency of responses for the age of first contraceptive usage were observed across different strengths of religiosity (p = 0.016) and for the self-perceived impact of religion on sexual health across different religious affiliations (p = 0.033) and strengths of religiosity (p = 0.005). All other differences were found not to be statistically significant. It was determined that increased strengths of religiosity resulted in delayed onset of contraceptive usage and that both different religious affiliations and greater strengths of religiosity lead to different self-perceived impacts of religion on sexual health despite low levels of current practice.


Subject(s)
Sexual Health , Pregnancy , Adolescent , Humans , Female , United States , Young Adult , Religion , Sexual Behavior , Contraception , Students
7.
Physiol Rep ; 11(22): e15856, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37985125

ABSTRACT

Overweight and obesity (Ow/Ob) is a risk factor for cardiometabolic disease. Caloric restriction (CR) have been investigated but little is known about the acute effects of CR and often such diets are not standardized. Thus, we aimed to assess the impact of a new standardized 3-day CR diet (590 kcal/d intake) on cardiometabolic health in weight-stable Ow/Ob individuals. In a single-arm design, 15 Ow/Ob men and women were assessed pre-post a 3-day standardized CR diet; specifically, body weight/composition (%body fat, visceral fat score (Vfs), blood pressure (BP), and vascular stiffness (VS), resting energy expenditure (REE), substrate utilization (respiratory quotient, RQ), and blood glucose/lipid profile). CR lowered body weight (93.1 ± 15.2 to 90.67 ± 14.4 kg, p < 0.001, d = 1.9), %fat (37.2 ± 7.5 to 35.8 ± 7.5%, p = 0.002, d = 1.1), and Vfs (13.1 ± 4.5 to 12.2 ± 3.9 a.u., p = 0.002, d = 1.1), but not body water (46.3 ± 3.6 to 46.0 ± 3.6%, p = 0.29). CR lowered VS (29.8 ± 17.5 to 21.5 ± 14.5%, p = 0.05, d = 0.6), but not BP (p > 0.05). Blood glucose (86 ± 7 to 84 ± 11 mg/dL, p = 0.33) and lipids (total cholesterol (196 ± 49 to 203 ± 54 mg/dL, p = 0.16) and TC/HDL (4.9 ± 2.4 to 6.1 ± 4.7, p = 0.13)) were unchanged. RQ decreased with CR (0.84 ± 0.01 to 0.76 ± 0.00, p < 0.001, d = 1.9), though REE was unchanged (p = 0.83). The 3-day CR diet significantly improved fat metabolism, body weight and composition, and vascular stiffness.


Subject(s)
Cardiovascular Diseases , Overweight , Female , Humans , Male , Blood Glucose/metabolism , Caloric Restriction , Cardiovascular Diseases/etiology , Cardiovascular Diseases/prevention & control , Obesity/metabolism , Overweight/metabolism , Weight Loss
8.
Front Sports Act Living ; 5: 1245788, 2023.
Article in English | MEDLINE | ID: mdl-37691642

ABSTRACT

Elite athletes require a delicate balance of physiological and psychological stress and recovery-essential for achieving optimal performance. Monitoring heart rate variability (HRV) provides a non-invasive estimation of both physiological and psychological stress levels, offering potentially valuable insights into health, performance, and adaptability. Previous studies, primarily conducted on male participants, have shown an association between HRV and performance in the context of rowing training. However, given the rigorous nature of rowing training, it is crucial to investigate HRV in elite rowers, particularly during the U.S. national selection regattas (NSR). Purpose: To comprehensively analyze elite female rowers, evaluating acute changes in HRV and subjective psychometrics during the NSR. Methods: Five elite female rowers (26 ± 2 years, 180 ± 8 cm, 82 ± 8 kg, 19 ± 6%fat) were recruited and tracked prior to and during NSR I and II. Morning HRV measures were completed using photoplethysmography (HRV4training) along with self-reported levels of fatigue, soreness, rating of perceived exertion, mentally energy and physical condition. Results: Significant decreases were observed in log transformed root-mean square of successive differences (LnRMSSD; p = 0.0014) and fatigue (p = 0.01) from pre-to-during NSR, while mental energy (p = 0.01), physical condition (p = 0.01), and motivation (p = 0.006) significantly increased. These psychometric measures returned to pre-NSR levels, at post-NSR (all p < 0.05), though HRV remained slightly suppressed. NSR on-water performance was not correlated to LnRMSSD or the change in LnRMSSD (p > 0.05). Discussion: HRV and psychometric measures are sensitive to the stress of elite rowing competition in females. However, HRV was not associated with on-water rowing performance during an elite rowing competition.

9.
BMC Sports Sci Med Rehabil ; 15(1): 83, 2023 Jul 11.
Article in English | MEDLINE | ID: mdl-37434243

ABSTRACT

BACKGROUND: Heat stress during aerobic exercise training may offer an additional stimulus to improve cardiovascular function and performance in a cool-temperate environment. However, there is a paucity of information on the additive effects of high-intensity interval exercise (HIIE) and acute heat stress. We aimed to determine the effects of HIIE in combination with acute heat stress on cardiovascular function and exercise performance. METHODS: Twelve active (peak O2 consumption [VO2peak]: 47 ± 8 ml·O2/min/kg) young adults were counterbalanced to six sessions of HIIE in hot (HIIE-H, 30 ± 1 °C, 50 ± 5% relative humidity [RH]) or temperate conditions (HIIE-T, 20 ± 2 °C, 15 ± 10% RH). Resting heart rate (HR), HR variability (HRV), central (cBP) and peripheral blood pressure (pBP), peripheral mean arterial pressure (pMAP), pulse wave velocity (PWV), VO2peak, and 5-km treadmill time-trial were measured pre- and post-training. RESULTS: Resting HR and HRV were not significantly different between groups. However, expressed as percent change from baseline, cSBP (HIIE-T: + 0.9 ± 3.6 and HIIE-H: -6.6 ± 3.0%, p = 0.03) and pSBP (HIIE-T: -2.0 ± 4.6 and HIIE-H: -8.4 ± 4.7%, p = 0.04) were lower in the heat group. Post-training PWV was also significantly lower in the heat group (HIIE-T: + 0.4% and HIIE-H: -6.3%, p = 0.03). Time-trial performance improved with training when data from both groups were pooled, and estimated VO2peak was not significantly different between groups (HIIE-T: 0.7% and HIIE-H: 6.0%, p = 0.10, Cohen's d = 1.4). CONCLUSIONS: The addition of acute heat stress to HIIE elicited additive adaptations in only cardiovascular function compared to HIIE alone in active young adults in temperate conditions, thus providing evidence for its effectiveness as a strategy to amplify exercise-induced cardiovascular adaptations.

11.
Prev Vet Med ; 214: 105888, 2023 May.
Article in English | MEDLINE | ID: mdl-36906938

ABSTRACT

For effective wild salmon (Salmo salar) conservation in areas where aquaculture of salmon is practiced it is necessary to identify where the key parasite, the salmon louse (Lepeophtheirus salmonis), will have an impact on these wild salmon. A simple modelling structure is implemented in a sample system in Scotland for assessing interaction between wild salmon and salmon lice from salmon farms. The model is demonstrated for case studies of smolt sizes and migration routes through salmon lice concentration fields derived for average farm loads from 2018 to 2020. Lice modelling describes production and distribution of lice, infection rates on hosts and biological development of lice. The modelling framework allows explicit assessment of the relationships between lice production, lice concentration and impact on hosts as they grow and migrate. Lice distribution in the environment is determined using a kernel model, which summarises mixing in a complex hydrodynamic system. Smolt modelling describes their initial size, growth and migration pathways. This is illustrated for a set of parameter values applied to 10 cm, 12.5 cm and 15 cm salmon smolts. We found that salmon lice impact depends on initial size of host, smaller smolts will be more susceptible, while larger smolts are less impacted by a given number of lice encounters and migrate more rapidly. This modelling framework can be adapted to allow evaluation of threshold concentrations of lice in the water that should not be exceeded to avoid impacts on smolt populations.


Subject(s)
Copepoda , Fish Diseases , Parasites , Salmo salar , Animals , Fish Diseases/parasitology , Aquaculture
12.
Eur J Appl Physiol ; 123(5): 1041-1050, 2023 May.
Article in English | MEDLINE | ID: mdl-36633663

ABSTRACT

PURPOSE: Heart rate variability (HRV) estimates the autonomic nervous system (ANS) influence on the heart and appears sex-specific. Sensory afferents exhibit sex-specificity; although, it is unknown if Capsaicin, an agonist for transient receptor potential vanilloid channel-1 (TRPV1), alters cardiac ANS activity in a sex-dependent manner, which could be important given the predictive nature of HRV on risk of developing hypertension. Thus, we explored if there was sex-specificity in the effect of capsaicin on estimated cardiac ANS activity. METHODS: HRV was measured in 38 young males (M: n = 25) and females (F: n = 13), in a blinded-crossover design, after acute ingestion of placebo or capsaicin. Resting HR, RR-interval, root-mean-square of successive differences (RMSSD), natural log-transformed RMSSD (LnRMSSD), standard deviation of n-n intervals (SDNN), number of pairs of successive n-n intervals differing by > 50 ms (NN50), and percent NN50 (PNN50) were obtained using standard techniques. RESULTS: Significant sex differences were observed in mean HR (M: 59 ± 9.3 vs. F: 65 ± 12 beats/min, p = 0.036, η2 = 0.098), minimum HR (M: 47 ± 8.3 vs. F: 56 ± 12 beats/min, p = 0.014, η2 = 0.124), and NN50 (M: 177 ± 143 vs. F: 29 ± 17, p < 0.001, η2 = 0.249). There was a significant interaction of sex*treatment (p = 0.02, η2 = 0.027) for RMSSD, where males increased (78 ± 55 vs. 91 ± 64 ms), and females decreased (105 ± 83 vs. 76 ± 43 ms), placebo vs. capsaicin. CONCLUSION: This controlled study recapitulates sex differences in HR and HRV, but revealed a sexual dimorphism in the parasympathetic response to capsaicin, perhaps due to differing TRPV1-afferent sensitivity, highlighting a potential mechanism for differential regulation of hemodynamics, and CVD risk, and should be considered in future studies.


Subject(s)
Capsaicin , Sex Characteristics , Humans , Male , Female , Heart Rate/physiology , Capsaicin/pharmacology , Autonomic Nervous System/physiology , Heart
13.
Obesity (Silver Spring) ; 31 Suppl 1: 139-149, 2023 02.
Article in English | MEDLINE | ID: mdl-36575144

ABSTRACT

OBJECTIVE: This study compared intermittent fasting and protein pacing (IF-P) versus a heart-healthy caloric restriction (CR) diet, matched for energy intake and physical activity energy expenditure, on body weight, total and visceral fat mass, and cardiometabolic health outcomes in adults with obesity. METHODS: IF-P (n = 21) and CR (n = 20) were assessed pre- (week 0), mid- (week 5), and post- (week 9) intervention. RESULTS: Both groups reduced (p < 0.05) weight, total and visceral fat mass, blood pressure and lipids, and desire to eat food and increased proportion of fat-free mass. IF-P resulted in greater (p < 0.05) reductions in weight (-9% vs. -5%), total (-16% vs. -9%) and visceral (-33% vs. -14%) fat mass, and desire to eat (-17% vs. 1%) and increased fat-free mass percent (6% vs. 3%) compared with CR. These improvements were despite similar weekly total energy intake (IF-P, 9470 ± 550 vs. CR, 9095 ± 608 kcal/wk; p = 0.90) and physical activity energy expenditure (IF-P, 300 ± 150 vs. CR, 350 ± 200 kcal/d; p = 0.79). CONCLUSIONS: IF-P and CR optimize weight loss, body composition, cardiometabolic health, and hunger management, with IF-P providing greater benefits.


Subject(s)
Caloric Restriction , Cardiovascular Diseases , Adult , Humans , Caloric Restriction/methods , Diet, Reducing/methods , Intra-Abdominal Fat , Intermittent Fasting , Body Composition , Fasting
14.
Microvasc Res ; 145: 104436, 2023 01.
Article in English | MEDLINE | ID: mdl-36113667

ABSTRACT

Endothelial dysfunction is associated with cardiovascular disease development, nitric oxide (NO) deficiencies, and may be limb or sex-specific. Prior in vitro work indicated that the transient receptor potential vanilloid channel-1 (TRPV1) is expressed in human arteries and the TRPV1 agonist capsaicin alters vasodilation in an endothelium-dependent manner; however, it is unknown if this translates in vivo or is limb or sex-dependent. Therefore, we sought to determine if there was limb or sex-specificity in the effect of capsaicin on microvascular function using near-infrared spectroscopy (NIRS)-derived tissue oxygen saturation (StO2) reperfusion slope. In a blinded placebo-controlled crossover design, 45 young males (M: n = 25) and females (F: n = 20), the reperfusion slopes of the forearm and quadriceps were assessed, and a urine sample obtained to assay for nitrate/nitrite (NOx) concentrations and antioxidant capacity after acutely ingesting placebo or capsaicin. Under placebo, females had greater reperfusion rates in both the forearm (M: 0.44 ± 0.24 vs. F: 0.98 ± 0.46 %/sec; p = 0.002, d = -1.50) and quadricep (M: 0.86 ± 0.31 vs. F: 1.17 ± 0.43 %/sec; p = 0.010, d = -0.85). Capsaicin decreased microvascular responsiveness in the forearm of females (placebo: 0.98 ± 0.45 vs. capsaicin: 0.84 ± 0.45 %/sec) as compared to males (placebo: 0.45 ± 0.24 vs. capsaicin: 0.38 ± 0.16 %/sec, interaction p < 0.001, η2 = 0.475). There was a sex*treatment interaction for NOx concentrations, where males increased (placebo: 21.13 ± 12.83 vs. capsaicin: 23.82 ± 13.34 µM), while females decreased (placebo: 22.78 ± 14.40 vs. capsaicin: 14.43 ± 10.01 µM; p = 0.037, η2 = 0.042). Using NIRS to assess microvascular function, there is apparent limb and sex-specificity, and, for the first-time, document that acute oral capsaicin alters reperfusion slope in a sexually divergent manner.


Subject(s)
Capsaicin , Spectroscopy, Near-Infrared , Male , Female , Humans , Capsaicin/pharmacology , Muscle, Skeletal/blood supply , Vasodilation , Forearm
15.
Int J Exerc Sci ; 16(6): 1244-1256, 2023.
Article in English | MEDLINE | ID: mdl-38288384

ABSTRACT

Blood flow restriction training (BFRT) uses occlusion during low-intensity resistance training (< 50% of 1-repetition maximum, 1RM) to reduce arterial blood flow and venous return, imposing greater metabolic stress but similar muscular hypertrophy and strength gains as high-intensity resistance training (HIRT). However, no study, to date, has incorporated BFRT in a collegiate strength and conditioning setting to assess ecological validity. We aimed to investigate the effects of adding 6-weeks of accessory BFRT or HIRT to NCAA Division III soccer players prescribed resistance training regimen on muscle strength and size. Male and female (n = 17) athletes were randomly assigned to complete biceps curls 2x/week under BFRT or control (HIRT), following regularly scheduled strength training. Bicep strength (1RM) and circumference (BC) were assessed at weeks 0, 3, and 6 (men only). In men, for BC no significant interaction of condition x time was observed (p = 0.861), though condition (BFRT vs Control, p = 0.025) and time (p = 0.024) were significant. For 1RM, there was no significant interaction of condition x time (BFRT vs HIRT, p = 0.067) or of condition (p = 0.598), but there was a significant effect of time (p = 0.004). In women, there was no significant interaction between time and condition (p = 0.765) or of condition (p = 0.971) on BC, but time was significant (p = 0.045). For 1RM, there was no significant interaction of condition x time (p = 0.227) or of condition (p = 0.741), but time was (p = 0.018). In this preliminary ecological study, BFRT induced similar increases in muscle strength and circumference as HIRT in soccer players, suggesting that BFRT could be incorporated into collegiate athlete training.

16.
Int J Exerc Sci ; 16(6): 1320-1333, 2023.
Article in English | MEDLINE | ID: mdl-38288383

ABSTRACT

The American College of Sports Medicine recommends resistance training using at least 70% one repetition maximum to improve muscular strength and hypertrophy; however, these intensities may not be safe for all populations. A training technique that has been reported to elicit increases in strength and muscle size uses low intensity resistance training or low load training in combination with blood flow restriction (BFR) to the working muscle. Although the acute effects of BFR on muscle strength and size are well established, the effects of BFR on muscular power are not definitively known. Resistance trained males (n = 14) completed three experimental sessions in which lower body power output and vertical jump height were measured pre and post exercise protocol. The barbell back squat was performed with either low load and blood flow restriction, high load (90% 1 RM, HL), or control (CON). A significant mean difference between pre (M = 46.35 ± 5.61 cm) and post (M = 43.63 ± 4.59 cm) vertical jump heights following 15 repetitions at 20% 1 RM with BFR was observed (p = 0.034), but not with HL or a CON. A decrement in vertical jump height was experienced after an acute bout of BFR with low load resistance exercise. Low load resistance exercise with BFR or high intensity resistance exercise may not be beneficial as part of a warm-up to acutely enhance vertical jump or power output.

18.
Int J Exerc Sci ; 15(4): 1262-1273, 2022.
Article in English | MEDLINE | ID: mdl-36582399

ABSTRACT

Treadmills are utilized as a training tool to improve aerobic fitness, but precise understanding of intensity and the corresponding physiological strain is critical for optimizing exercise prescription and associated adaptations. Running on non-motorized, curved treadmills may result in greater oxygen uptake (VO2), increased heart rate (HR), and increased rating of perceived exertion (RPE) compared to traditional motorized treadmills. The purpose of this study was to investigate the physiological responses on non-motorized versus traditional motorized treadmills during speed-matched running. Participants were 4 college-aged, recreationally active females. HR, VO2, respiratory exchange ratio (RER), and RPE were monitored during 3 speed-matched stages of incremental exercise in two conditions: the non-motorized Assault AirRunner and a traditional motorized treadmill, as well as for 5 minutes post-exercise. VO2, RER, and HR were greater in the Assault condition (ESVO2 = 0.998, ESRER = 0.839, ESHR = 0.972, p < 0.05). While not significant between groups, RPE showed a greater increase with increasing speeds in the Assault condition (ES = 0.728), as did RER (ES = 0.800, p < 0.05). Cumulative excess-post exercise oxygen consumption (EPOC) during a five-minute period post-exercise was also greater in the Assault condition, and HR and RER remained higher five minutes post-exercise in the Assault condition (ESEPOC = 0.738, ESHR = 1.600, ESRER = 2.075, p < 0.05). The Assault AirRunner elicited greater physiological responses (VO2, carbohydrate usage, and HR) in response to speed-matched running in comparison to a traditional motorized treadmill in active college-aged females. Collectively, aerobic exercise conducted on the Assault AirRunner has a greater physiological and perceived intensity and need to be taken into consideration when designing and implementing training programs or testing.

19.
Mar Pollut Bull ; 185(Pt A): 114268, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36343548

ABSTRACT

This study presents the results of analyses of data on infections of 2646 whiting Merlangius merlangus with the monogenean Diclidophora merlangi. All fish were caught in the North Sea and off the north coast of Scotland in 1990, 1993 and 1995. The aims were to analyse these data in relation to the locations of whiting sampling stations and oil installations active at that time, and to evaluate the results in terms of D. merlangi as an indicator of hydrocarbon pollution. Mean abundance of D. merlangi increased significantly with increasing proximity to the nearest oil field, with an accelerated rate of increase within approximately 2 km of the oil field. Age of oil field and whiting length showed no significant effect on parasite abundance, but there was a small difference between years. The results support those of previous studies in demonstrating the value of monogeneans as indicators of hydrocarbon pollution.


Subject(s)
Gadiformes , Trematoda , Animals , North Sea , Fishes/parasitology , Hydrocarbons
20.
Nutrients ; 14(19)2022 Oct 02.
Article in English | MEDLINE | ID: mdl-36235747

ABSTRACT

The potential role of proteinase activated receptor 2 (PAR2) in the development of age-related obesity and insulin resistance is not well-understood. To address the hypothesis that deletion of PAR2 might ameliorate age-related obesity and impaired glucose homeostasis, we assessed body composition and insulin action in 18-month-old male PAR2 knockout (PAR2KO-AG), age-matched (AG) and young C57BL6 (YG, 6-month-old) mice. Body composition was measured by magnetic resonance spectroscopy (MRS) and insulin action was assessed by glucose tolerance (GT), insulin tolerance (IT) and AICAR tolerance (AT) testing. AG mice weighed significantly more than YG mice (p = 0.0001) demonstrating age-related obesity. However, PAR2KO-AG mice weighed significantly more than AG mice (p = 0.042), indicating that PAR2 may prevent a portion of age-related obesity. PAR2KO-AG and AG mice had greater fat mass and body fat percentage than YG mice. Similar to body weight, fat mass was greater in PAR2KO-AG mice compared to AG mice (p = 0.045); however, only a trend for greater body fat percentage in PAR2KO-AG compared to AG mice was observed (p = 0.09). No differences existed in lean body mass among the PAR2KO-AG, AG, and YG mice (p = 0.58). With regard to insulin action, the area under the curve (AUC) for GT was lower in PAR2KO-AG compared to AG mice (p = 0.0003) and YG mice (p = 0.001); however, no differences existed for the AUC for IT or AT. Our findings indicate that age-related obesity is not dependent on PAR2 expression.


Subject(s)
Body Composition , Insulin Resistance , Receptor, PAR-2 , Animals , Body Weight , Diet, High-Fat , Glucose/metabolism , Insulin/metabolism , Male , Mice , Mice, Inbred C57BL , Obesity/metabolism , Receptor, PAR-2/genetics , Receptor, PAR-2/metabolism
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