Postactivation Performance Enhancement in Healthy Adults Using a Bodyweight Conditioning Activity: A Systematic Review and Meta-analysis.

ABSTRACT: Brink, NJ, Constantinou, D, and Torres, G. Postactivation performance enhancement in healthy adults using a bodyweight conditioning activity: a systematic review and meta-analysis. J Strength Cond Res 37(4): 930-937, 2023-A systematic review and meta-analysis were conducted to review the available evidence on whether a bodyweight conditioning activity can acutely improve the performance outcome of a subsequent task through postactivation performance enhancement. Data sources included PubMed (National Library of Medicine), Web of Science (Clarivate Analytics), Google Scholar, SPORTDiscuss (EBSCO), Embase (Elsevier), and Thesis Global. Subjects were healthy, active adults who performed either a vertical jump or a linear sprint outcome measurement. All studies were randomized controlled trials where the effects of a bodyweight conditioning activity were compared with a control condition. The control group followed the same course as the experimental group excluding the intervention, with the intervention and outcome measurement carried out in the same session. The intervention was completed before the initiation of the outcome measure testing. Nineteen studies fulfilled the eligibility criteria and were included. There was a small overall effect of 0.30 (95% confidence interval 0.14-0.46, p = 0.0003) in favor of using a bodyweight conditioning activity to improve the outcome of a subsequent vertical jump or linear sprint. Secondary analysis indicated that there was no difference between the vertical jump and sprint subgroup, <5 minutes or 5 minutes and greater between the intervention and outcome measurement subgroup, or whether an intervention with the same movements or different movements was used before the outcome task subgroup. Using bodyweight conditioning activities before performing a maximal vertical jump or sprint may provide a small benefit in performance outcome.

Exercise is the Most Important Medicine for COVID-19.

ABSTRACT: COVID-19 infection and long COVID affect multiple organ systems, including the respiratory, cardiovascular, renal, digestive, neuroendocrine, musculoskeletal systems, and sensory organs. Exerkines, released during exercise, have a potent crosstalk effect between multiple body systems. This review describes the evidence of how exerkines can mitigate the effects of COVID-19 in each organ system that the virus affects. The evidence presented in the review suggests that exercise should be considered a first-line strategy in the prevention and treatment of COVID-19 infection and long COVID disease.

Cardio-Respiratory Fitness and Cardiovascular Disease Risk Factors Among South African Medical Students.

Cardiovascular disease (CVD) risk factors have been associated with CVD mortality, and physicians use CVD risk factor profiles (smoking, dyslipidemia, hypertension, etc.) to address patient health. Furthermore, cardio-respiratory fitness (CRF) has been shown to be an independent risk factor for CVD and all-cause mortality. Cardio-respiratory fitness is also the risk factor that contributes the highest percentage to all-cause deaths when compared to other traditional risk factors. In addition, studies have reported that adding CRF to established CVD risk factors improves the precision of prediction for CVD morbidity and mortality. Medical students tend to adopt sedentary and unhealthy lifestyles during the course of their education that negatively affect CVD risk factors and CRF. The majority of research on CVD risk, health status and lifestyle factors of medical students has used self-reported data and questionnaires for CVD risk factors and not included CRF in the health status measurements. In addition, studies have found that future medical doctors' own health and lifestyle practices influence their counselling activities. Allowing future medical doctors to assess their personal CVD risk factors and CRF may thus be important in their use of physical activity counselling with patients' lifestyle management for health benefits and improvement. A descriptive, cross-sectional cohort study design was used with the aim to determine CVD risk factors using CRF measures and physical activity levels in a cohort of South African medical students. The most significant finding was that they were not meeting the PA levels recommended to maintain health and lower CVD risk.

Employee Perceptions of an Established Health and Wellness Coaching Program to Improve Behavior.

OBJECTIVE: There is limited evidence, particularly qualitative analysis, of health and wellness interventions within the South African workplace. The purpose of this study is to explore whether health and wellness coaching when offered as part of an employee wellness program has potential for developing lifestyle change in a South African workplace. METHODS: There were four, 45-minute focus group discussions, where employees discussed their experiences of the workplace health and wellness intervention program. RESULTS: Main categories identified from the coding of the transcripts were purpose of the health and wellness coaching program, as well as employees' program experience and improvement to the program. Common barriers to engagement, positive and negative experiences, and suggested improvements were defined by the employees. CONCLUSIONS: The study highlighted the need of understanding employee perceptions in the development and implementation of a workplace health and wellness program.

Acceptability and feasibility of home-based hypertension and physical activity screening by community health workers in an under-resourced community in South Africa.

Background: Low-middle-income countries (LMICs) face increasing burdens from non-communicable disease (NCDs) requiring primary care task shifting to community health workers (CHWs). This study explored community members' perceptions of NCD-focused, CHW-led home visits in a historically disadvantaged township of South Africa. Methods: Trained CHWs visited community member homes, performing blood pressure and physical activity (PA) screenings, followed by brief counselling and a satisfaction survey. Semi-structured interviews were conducted within 3 days of the visit to learn about their experiences. Results: CHWs visited 173 households, with 153 adult community members consenting to participate (88.4%). Participants reported that it was easy to understand CHW-delivered information (97%), their questions were answered well (100%), and they would request home service again (93%). Twenty-eight follow-up interviews revealed four main themes: 1) acceptance of CHW visits, 2) openness to counselling, 3) satisfaction with screening and a basic understanding of the results, and 4) receptiveness to the PA advice. Conclusion: Community members viewed CHW-led home visits as an acceptable and feasible method for providing NCD-focused healthcare services in an under-resourced community. Expanding primary care reach through CHWs offers more accessible and individualized care, reducing barriers for individuals in under-resourced communities to access support for NCD risk reduction.

Postactivation performance enhancement (PAPE) of sprint acceleration performance.

Postactivation performance enhancement (PAPE) is a principle that an acute bout of high-intensity voluntary exercise is followed by an enhancement in strength, speed or power production. This study intended to show a direct correlation between intensity, specificity and the outcome of a maximal task of sprint accelerations compared to a previously defined weighted plyometric intervention. In a randomised controlled, double-blind trial, professional footballers undertook 20 m maximal sprint accelerations at a baseline and at 2 and 6 min post-intervention after 1 of 3 interventions; 2 repetitions of 20 m sprint accelerations (S), 3 × 10 alternative leg weighted bounding (P) and control (C). Relative to the baseline there was a significant improvement for S over 10 and 20 m at 2 min of 0.12m.s-1 and 0.11m.s-1 and 6 min of 0.11m.s-1 and 0.12m.s-1. Relative to the baseline P also had a significant improvement over 10 and 20 m at 2 min 0.09m.s-1 and 0.09m.s-1 and 6 min of 0.11m.s-1 and 0.09m.s-1. There was a significant improvement in C between 2 and 6 min post-intervention at 10 and 20 m of 0.06m.s-1 and 0.08m.s-1. This finding suggests a maximal sprint acceleration may enhance the outcome of a subsequent maximal sprint acceleration at 2 min, but the latter results could not be directly attributed to the interventions as previous testing is likely to have influenced these outcomes.

Postactivation performance enhancement (PAPE) using a vertical jump to improve vertical jump performance.

BACKGROUND: Postactivation performance enhancement (PAPE) is a principle that suggests that an acute bout of high intensity voluntary exercise will be followed by an improvement in strength, power, and speed of a subsequent task. This study intended to demonstrate how a maximal vertical jump (VJ) can enhance the outcome of a subsequent VJ compared to a multiple jump series (MJ) and a control. METHODS: In a randomized controlled, double blind trial, adult professional soccer players (N.=69) undertook maximal VJs at baseline and at 2 and 6 minutes postintervention after 1 of 3 interventions; 2 repetitions of a maximal VJ, 40 repetitions of a MJ or a walking control (CON). RESULTS: All baseline outcomes were similar between all the groups. Relative to the baseline there was a significant improvement for VJ in jump height and power output at 2 minutes of 1.89cm and 114.45W and relative to the baseline, MJ also had a significant improvement at 2 minutes of 1.51cm and 91.60W. By 6 minutes both groups had reverted to baseline values. There was no change in CON across the experiment and no significant difference between CON and the interventions. CONCLUSIONS: These findings suggest that 2 maximal VJs may enhance the outcome of a subsequent maximal VJ after 2 minutes and as much as a series of 40 jumps. However, these enhancements were not sustained for a further 4 minutes in either group.

Comparison of High-Intensity Training Versus Moderate-Intensity Continuous Training on Cardiorespiratory Fitness and Body Fat Percentage in Persons With Overweight or Obesity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: High-intensity training is comprised of sprint interval training (SIT) and high-intensity interval training (HIIT). This study compared high-intensity training with moderate-intensity continuous training (MICT) on cardiorespiratory fitness (CRF) and body fat percentage for overweight or obese persons. METHODS: A systematic search of randomized controlled trials using the health science databases occurred up to April, 2020. Twenty-six studies were included for complete analysis. A total of 784 participations were analyzed. The unstandardized mean difference for each outcome measurement was extracted from the studies and pooled with the random effects model. RESULTS: MICT was significantly better at improving CRF compared with SIT (mean difference = -0.92; 95% confidence interval, -1.63 to -0.21; P = .01; I2 = 10%). Furthermore, there was no significant difference between MICT versus HIIT on CRF (mean difference = -0.52; 95% confidence interval, -1.18 to 0.13; P = .12; I2 = 23%). There was no significant difference in body fat percentage between MICT versus HIIT and MICT versus SIT. CONCLUSIONS: MICT was significantly better at improving CRF than SIT in overweight or obese persons.

The Relationship of VO2 Peak and the Blood Lactate Transition Threshold with Metabolic Syndrome and Its Component Disorders.

Background: Improvements in cardiorespiratory fitness attenuate the risk for metabolic syndrome (MetS). However, the determinants of cardiorespiratory fitness measurements such as oxygen consumption (VO2) peak and anaerobic threshold (AT) have not been investigated in persons with MetS. Therefore, the main aim of this study was to compare VO2 peak and AT between subjects with and without MetS and to investigate determinants of cardiorespiratory fitness and its effects on the odds for MetS and its individual components. Methods: Thirty-one males with MetS and 24 healthy male participants each performed a VO2 peak and a blood lactate transition threshold test. Waist circumference, body mass index (BMI), blood pressure, fasting plasma triglyceride, total cholesterol, high-density lipoprotein cholesterol, glucose, and insulin levels were measured. Separate multivariable linear regression models were developed in which VO2 peak, AT, and the components of MetS were used as the dependent variables, while a multivariable logistic regression model was used for MetS. Results: The VO2 peak [median (interquartile range)] was lower in subjects with MetS compared with controls [27.9 (23.0-31.0) vs. 35.0 (32.0-45.0) mL·min-1·kg-1; P < 0.0001]. Multivariable regression analysis demonstrated that there was a bidirectional association between MetS and VO2 peak that was mediated by waist circumference and blood pressure. The VO2 peak was a strong negative determinant of waist circumference (ß = -0.36, P < 0.0001), but not of BMI (ß = -0.13, P = 0.21). Conclusions: A higher VO2 peak is associated with a lower odds ratio for MetS, which is related to greater cardiorespiratory fitness in a cyclical relationship that is mediated by blood pressure and waist circumference. A higher VO2 peak is specifically associated with lower waist circumference, and vice versa, possibly by effects on visceral fat.

Reproducibility and levels of blood lactate transition thresholds in persons with metabolic syndrome.

BACKGROUND: The optimal exercise load/intensity for exercise programs for individuals with metabolic syndrome has not been investigated. One method of determining optimal exercise load is to measure the blood lactate transition threshold (BLTT), referred to as the anaerobic threshold (AT). This study investigated the reproducibility of BLTT testing and the consequent determination of AT via the Mader method and a modified form of the Automatic Data Analysis for Progressive Tests (ADAPT) method in patients with metabolic syndrome. METHODS: Fifteen, male patients diagnosed with metabolic syndrome and 15 healthy, male subjects each performed BLTT measurements on a treadmill at the same daily times on three different days. Peak oxygen consumption was also determined during testing. RESULTS: There was no significant difference in treadmill velocity at AT determined by the Mader method or the modified ADAPT method within both groups (P>0.05). Both methods yielded good coefficients of variation. When combining both groups, the typical error also demonstrated good reproducibility. The mean treadmill velocity at AT was higher in the healthy compared to the metabolic syndrome group using both the Mader and the ADAPT method. Regression analysis and analysis of covariance (ANCOVA) demonstrated that this difference was largely due to a higher oxygen consumption (VO2) peak in the healthy group. The study also found an association between VO2 peak and waist circumference among the metabolic syndrome group. CONCLUSIONS: This study demonstrated that BLTT tests are reproducible in persons with metabolic syndrome. The modified ADAPT method may be the preferred method of determining treadmill velocity at AT because fewer factors are known to influence its determination.