Characteristics of torque production of the lower limb are significantly altered after 2 hours of treadmill load carriage

Load carriage is seldom completed in isolation, meaning load bearers need to be physically capable of physical activity after the load carriage task. This study aims to examine changes in lower limb muscle strength, as measured by torque production across a range of joint angles as a result of prolonged load carriage. Thirty-four healthy participants underwent two hours of loaded or unloaded treadmill load carriage, with lower limb muscle function variables assessed pre and post activity. The loaded group had a mass of (Mean(range)) 76.45 (27.12)kg, stature: 178.56 (17.63)cm, age: 23(6)yrs, and comprised of 13 males and 3 females. While the unloaded group had a body mass of 73.69(24.19)kg, stature: 178.89(18.49)cm, age: 22(5)yrs and comprised of 14 males and 4 females. Significant reductions across a range of parameters were observed. Characterised by reductions at the optimum muscle length for torque output, with all aspects demonstrating large (knee extension at 180˚·s-1: 0.51 Standardised SD, knee extnsion at 60˚·s-1: 0.98 standardised SD) or extremely large individual differences (knee flexion at 180˚·s-1: 2.17 standardised SD). These findings suggest after the completion of the load carriage task participants are in a significantly reduced physical state, which may have implications for secondary tasks

High-Intensity Interval Training and Cardiometabolic Health in the General Population: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Background: High-intensity interval training (HIIT) remains a promising exercise mode in managing cardiometabolic health. Large-scale analyses are necessary to understand its magnitude of effect on important cardiometabolic risk factors and inform guideline recommendations. Objective: We aimed to perform a novel large-scale meta-analysis on the effects of HIIT on cardiometabolic health in the general population. Methods: PubMed (MEDLINE), the Cochrane library and Web of Science were systematically searched. Randomised controlled trials (RCTs) published between 1990 and March 2023 were eligible. Research trials reporting the effects of a HIIT intervention on at least one cardiometabolic health parameter with a non-intervention control group were considered. Results: This meta-analysis included 97 RCTs with a pooled sample size of 3399 participants. HIIT produced significant improvements in 14 clinically relevant cardiometabolic health parameters, including peak aerobic capacity (VO2) [weighted mean difference (WMD): 3.895 ml min⁻¹ kg⁻¹, P < 0.001), left ventricular ejection fraction (WMD: 3.505%, P < 0.001), systolic (WMD: − 3.203 mmHg, P < 0.001) and diastolic (WMD: − 2.409 mmHg, P < 0.001) blood pressure, resting heart rate (WMD: − 3.902 bpm, P < 0.001) and stroke volume (WMD: 9.516 mL, P < 0.001). Body composition also significantly improved through reductions in body mass index (WMD: − 0.565 kg m⁻², P < 0.001), waist circumference (WMD: − 2.843 cm, P < 0.001) and percentage body fat (WMD: − 0.972%, P < 0.001). Furthermore, there were significant reductions in fasting insulin (WMD: − 13.684 pmol L⁻¹, P = 0.004), high-sensitivity C-reactive protein (WMD: − 0.445 mg dL⁻¹, P = 0.043), triglycerides (WMD: − 0.090 mmol L⁻¹, P = 0.011) and low-density lipoprotein (WMD: − 0.063 mmol L⁻¹, P = 0.050), concurrent to a significant increase in high-density lipoprotein (WMD: 0.036 mmol L⁻¹, P = 0.046). Conclusion: These results provide further support for HIIT in the clinical management of important cardiometabolic health risk factors, which may have implications for physical activity guideline recommendations

Aortic regurgitation in athletes: The challenges of echocardiographic interpretation

Background Bicuspid aortic valve (BAV) is the most common congenital cardiac defect and prone to premature degeneration causing aortic regurgitation (AR). The assessment of AR in athletic individuals poses several challenges as the pathological left ventricle (LV) remodelling caused by AR may overlap with the physiological remodelling of intense exercise. The purpose of this study is to highlight these challenges, review the existing literature and discuss how to tackle these conundrums. As a real-world example, we compare the resting transthoracic echocardiographic (TTE) findings in a cohort of individuals with BAV and AR, sub-grouped into “highly active” or “lightly active”. Methods Adult male subjects with an index TTE performed at a tertiary referral centre between 2019 and 2022 were included if the TTE confirmed a BAV and at least moderate AR. Further strict inclusion criteria were applied and parameters of valve disease severity was made in accordance with existing guidelines. Subjects completed a physical activity questionnaire over the telephone, and were classified into either group 1: “highly active” or group 2: “lightly active” based on their answers. Demographics and TTE parameters were compared between the two groups. Results 30 male subjects (mean age 44±13 years) with BAV-AR were included – 17 were highly active, and 13 lightly active. There was no significant difference in age (group 1, 45±12.7yrs vs group 2, 42±17yrs; p=0.49), height (p=0.45), weight (p=0.268) or severity of AR, when quantitative assessment was possible. Group 1 had a significantly higher stroke volume (131±17mls vs 102±13 mls; p=0.027), larger LV volumes, diastolic dimensions and significantly larger bi-atrial and right ventricular size. This LV dilatation in the context of AR and athleticism poses a diagnostic and management conundrum. Despite this, none of these 17 highly active individuals demonstrated any of the traditional criteria used to consider surgery. Conclusion There is significant overlap between the physiological adaptations to exercise and those caused by AR. Multi-modality imaging and stress testing can aid clinicians in diagnostic and management decisions in exercising individuals when there is discordance between AR severity and symptoms

Continuous cardiac autonomic and haemodynamic responses to isometric exercise in females

Purpose: Hypertension is associated with impaired haemodynamic control mechanisms and autonomic dysfunction. Isometric exercise (IE) interventions have been shown to improve autonomic modulation and reduce blood pressure (BP) in predominantly male participants. The physiological responses to IE are under explored in female populations; therefore, this study investigated the continuous cardiac autonomic and haemodynamic response to a single bout of IE in a large female population. Methods: Forty physically inactive females performed a single, individually prescribed isometric wall squat training session. Total power spectral density of heart rate variability (HRV) and associated low frequency (LF) and high-frequency (HF) power spectral components, were recorded in absolute (ms2) and normalised units (nu) pre, during and post an IE session. Heart rate (HR) was recorded via electrocardiography and baroreceptor reflex sensitivity (BRS) via the sequence method. Continuous blood pressure was recorded via the vascular unloading technique and stroke volume via impedance cardiography. Total peripheral resistance (TPR) was calculated according to Ohm’s Law. Results: During IE, there were significant reductions in HRV (p<0.001) and BRS (p<0.001), and significant increases in heart rate (p<0.001), systolic, mean and diastolic BP (p<0.001 for all). In recovery following the IE session, cardiac autonomic parameters returned to baseline (p=0.974); however, total peripheral vascular resistance significantly reduced below baseline (p<0.001). This peripheral vascular response was associated with significant reductions in systolic (-17.3±16.5 mmHg, p<0.001), mean (-18.8±17.4 mmHg, p<0.001) and diastolic BP (-17.3±16.2 mmHg, p<0.001), below baseline. Conclusion: A single IE session is associated with improved haemodynamic cardiovascular responses in females. Cardiac autonomic responses return to baseline values, which suggests alternative mechanisms are responsible for the post exercise haemodynamic improvements in females. Future mechanistic research is required to investigate the acute and chronic effects of IE in female populations with different resting BP profiles

Geometric View of Measurement Errors

The slope of the best fit line from minimizing the sum of the squared oblique errors is the root of a polynomial of degree four. This geometric view of measurement errors is used to give insight into the performance of various slope estimators for the measurement error model including an adjusted fourth moment estimator introduced by Gillard and Iles (2005) to remove the jump discontinuity in the estimator of Copas (1972). The polynomial of degree four is associated with a minimun deviation estimator. A simulation study compares these estimators showing improvement in bias and mean squared error

The implementation of a home-based isometric wall squat intervention using ratings of perceived exertion to select and control exercise intensity: a pilot study in normotensive and pre-hypertensive adults.

Isometric exercise (IE) and isometric wall squat (IWS) training have been shown to be effective methods of reducing arterial blood pressure. However, most IE interventions require methodologies and equipment that could present a barrier to participation. Therefore, this study aimed to examine the effectiveness of an accessible RPE prescribed IWS intervention. Thirty normotensive and pre-hypertensive adults were randomly assigned to a control group or one of two 4-week home-based IWS intervention groups: the first group conducted IWS exercise where intensity was prescribed and monitored using RPE (RPE-EX), whilst the other used a previously validated HR prescription method (HR-EX). Resting and ambulatory heart rate (HR) and blood pressure (BP) were measured pre- and post-intervention. Minimum clinically important differences (MCID; - 5 mmHg) in SBP and/or DBP were shown in 100% of intervention participants. Statistically significant reductions were shown in resting seated BP (RPE-EX: SBP: - 9 ± 6, DBP: - 6 ± 4, MAP: - 6 ± 3 mmHg; HR-EX: SBP: - 14 ± 6, DBP: - 6 ± 4, MAP: - 8 ± 4 mmHg), supine BP (RPE-EX: SBP: - 8 (- 5), DBP: - 8 (- 7), MAP: - 8 (- 4) mmHg; HR-EX: SBP: - 5 (- 4), MAP - 5 (- 4) mmHg), and ambulatory SBP (RPE-EX: - 8 ± 6 mmHg; HR-EX: - 10 ± 4 mmHg) following the interventions. There were no statistically significant differences between intervention groups in the magnitude of BP reduction. RPE prescribed IWS exercise can provide an effective and more accessible method for reducing BP at home, providing reductions comparable to the current HR-based prescription method. [Abstract copyright: © 2023. The Author(s).

Left Ventricular Function and Cardiac Biomarker Release-The Influence of Exercise Intensity, Duration and Mode: A Systematic Review and Meta-Analysis.

OBJECTIVE: We performed a systematic review, meta-analysis and meta-regression of exercise studies that sought to determine the relationship between cardiac troponin (cTn) and left ventricular (LV) function. The second objective was to determine how study-level and exercise factors influenced the variation in the body of literature. DATA SOURCES: A systematic search of Pubmed Central, Science Direct, SPORTDISCUS and MEDLINE databases. ELIGIBILITY CRITERIA: Original research articles published between 1997 and 2018 involving > 30 mins of continuous exercise, measuring cardiac troponin event rates and either LV ejection fraction (LVEF) or the ratio of the peak early (E) to peak late (A) filling velocity (E/A ratio). DESIGN: Random-effects meta-analyses and meta-regressions with four a priori determined covariates (age, exercise heart rate [HR], duration, mass). REGISTRATION: The systematic search strategy was registered on the PROSPERO database (CRD42018102176). RESULTS: Pooled cTn event rates were evident in 45.6% of participants (95% confidence interval (CI) 33.6-58.2); however, the overall effect was non-significant (P > 0.05). There were significant (P < 0.05) reductions in E/A ratio of - 0.38 (SMD = - 1.2, 95% CI - 1.4 to - 1.0), and LVEF of - 2.02% (SMD = - 0.38, 95% CI - 0.7 to - 0.1) pre- to post-exercise. Increased exercise HR was a significant predictor of troponin release and E/A ratio. Participant age was negatively associated with cTn release. There was a significant negative association between E/A ratio with increased rates of cTn release (P < 0.05). CONCLUSIONS: High levels of statistical heterogeneity and methodological variability exist in the majority of EICF studies. Our findings show that exercise intensity and age are the most powerful determinants of cTn release. Diastolic function is influenced by exercise HR and cTn release, which implies that exercise bouts at high intensities are enough to elicit cTn release and reduce LV diastolic function. Future EICF studies should (1) utilise specific echocardiographic techniques such as myocardial speckle tracking, (2) ensure participants are euhydrated during post-exercise measurements, and (3) repeat measures in the hours following exercise to assess symptom progression or recovery. It is also recommended to further explore the relationship between aging, training history, and exercise intensity on cTn release and functional changes

A 4-week resistance training intervention improves stability, strength and neuromuscular activity in the lower limb: a case study of a cerebral palsy adult

Spastic diplegia, a form of cerebral palsy, is a neurological disorder that results in some degree of spasticity. It is often associated with impairment of both normal and selective movement of the lower limbs, and some degree of muscular weakness. Resistance training is an established exercise intervention with numerous neurological benefits. Evidence suggests that resistance training can positively improve stability in young populations with cerebral palsy. However, little research exists in adult populations, who are at greater risk of inactivity due to ageing and an increase in sedentarism. A single-subject (aged 35-years old, 150.5 centimetres, 81 kilograms) case-study was therefore carried out to investigate the effectiveness of a 4-week resistance training intervention on stability, neuromuscular activity and force output in a male adult with cerebral palsy. The variables measured were total centre of pressure displacement, peak torque in both the quadriceps and hamstrings and Surface Electromyography (sEMG) activity in the Rectus Femoris (RF), Vastus Lateralis (VL), Biceps Femoris (BF) and Semitendinosus (ST). The results demonstrated that a 4-week resistance training intervention reduced total centre of pressure displacement (-51.34%) whilst concomitantly increased sEMG output (RF left +80% right +22%, VL left +160% right +26%, BF left +203% right +44%, ST left +40% right +90%) and peak torque values (right leg extension -7%, right leg flexion +29%, left leg extension +11%, left leg flexion +42%). In conclusion, this case study demonstrates that a 4-week resistance training intervention improves the stability of the participant, possibly through neurological adaptations and improvements to lower limb strength

Nurses’ experiences of clinical commissioning group boards

The following paper is the first in a series of three papers to highlight current practice among governing body nurses, that is, nurses who hold the statutory role of nurse member on clinical commissioning groups in England. In this paper we present findings from a small pilot study into these nurses’ experiences of Clinical Commissioning Groups. Their roles have emerged at a time of organisational change and in a period following extensive criticism of nursing and nurses in the media. We suggest that nurses’ roles and experiences are affected by these contextual ‘events’ and by the emerging structures and diversity of clinical commissioning groups. We argue that governing body nurses’ effectiveness in leading nurses and nursing on clinical commissioning groups may be affected by their relationships with other nurses, especially senior nurses, within clinical commissioning group localities. We suggest that it is timely to evaluate the effectiveness of statutory nurse member roles in influencing decision making on Clinical Commissioning Groups

The implementation of problem based learning styles to teach the Coach-Athlete relationship to undergraduate Sport and Exercise Science students

This study explored problem based learning (PBL) styles and it’s suitability to improve the learning experience of level 6 (third year) Sport and Exercise Science undergraduate university students compared to a traditional style of lecturing when teaching the Coach-Athlete relationship. Sixty-four (Mage years=23.47, SD=3.44) students attended a lecture on the topic of the Coach-Athlete relationship. A PBL task was implemented using images of a coach showing a hostile approach and another image of a coach using a friendly approach. These images were used to initiate discussions about the potential problems the scenarios could elicit. At the end of the session student’s completed a questionnaire regarding their thoughts about the session’s ability to aid learning and whether they felt it was preferred over a traditional style of lecturing as well as their enjoyment of the session. Eighty one percent (n=52) of participants found the task helpful to aid learning, 66% (n=42) of participants indicated that using this style of lecture could aid learning more than a traditional approach and 73% (n=47) of participants enjoyed the task. It may be useful to use PBL styles in lecture sessions to engage students within the topic area of the Coach-Athlete relationship. PBL could also be used to help develop transferable skills for those students who want to pursue a career in coaching