Impacts of heat exposure in utero on long-term health and social outcomes: a systematic review.

BACKGROUND: Climate change, particularly global warming, is amongst the greatest threats to human health. While short-term effects of heat exposure in pregnancy, such as preterm birth, are well documented, long-term effects have received less attention. This review aims to systematically assess evidence on the long-term impacts on the foetus of heat exposure in utero. METHODS: A search was conducted in August 2019 and updated in April 2023 in MEDLINE(PubMed). We included studies on the relationship of environmental heat exposure during pregnancy and any long-term outcomes. Risk of bias was assessed using tools developed by the Joanna-Briggs Institute, and the evidence was appraised using the GRADE approach. Synthesis without Meta-Analysis (SWiM) guidelines were used. RESULTS: Eighteen thousand six hundred twenty one records were screened, with 29 studies included across six outcome groups. Studies were mostly conducted in high-income countries (n = 16/25), in cooler climates. All studies were observational, with 17 cohort, 5 case-control and 8 cross-sectional studies. The timeline of the data is from 1913 to 2019, and individuals ranged in age from neonates to adults, and the elderly. Increasing heat exposure during pregnancy was associated with decreased earnings and lower educational attainment (n = 4/6), as well as worsened cardiovascular (n = 3/6), respiratory (n = 3/3), psychiatric (n = 7/12) and anthropometric (n = 2/2) outcomes, possibly culminating in increased overall mortality (n = 2/3). The effect on female infants was greater than on males in 8 of 9 studies differentiating by sex. The quality of evidence was low in respiratory and longevity outcome groups to very low in all others. CONCLUSIONS: Increasing heat exposure was associated with a multitude of detrimental outcomes across diverse body systems. The biological pathways involved are yet to be elucidated, but could include epigenetic and developmental perturbations, through interactions with the placenta and inflammation. This highlights the need for further research into the long-term effects of heat exposure, biological pathways, and possible adaptation strategies in studies, particularly in neglected regions. Heat exposure in-utero has the potential to compound existing health and social inequalities. Poor study design of the included studies constrains the conclusions of this review, with heterogenous exposure measures and outcomes rendering comparisons across contexts/studies difficult. TRIAL REGISTRATION: PROSPERO CRD 42019140136.

A WHO-led global strategy to control greenhouse gas emissions: a call for action.

BACKGROUND: Climate change, driven by anthropogenic greenhouse gas emissions, is among the greatest threats to human health. The World Health Organisation (WHO), has led global efforts to respond to emerging public health threats including the control of hazardous substances such as tobacco, alcohol, lead and asbestos, with remarkable health gains. BODY: Despite WHO's clear messaging on the enormous and growing health risks of climate change, greenhouse gases are not yet classified as hazardous substances, requiring control through a global strategy or framework. Additionally, WHO has not classified disease attributable to climate change as a result of the promulgation of these hazards as a Public Health Emergency of International Concern (PHEIC), despite the serious and preventable health risks it poses globally. Several historical precedents set the stage for WHO to declare excess greenhouse gases as health hazards, including the control of ozone-depleting substances and breast-milk substitutes where the public benefit of control exceeded the potential benefit of their promulgation. In addition, WHO's undertaking within the International Health Regulations to protect global health, providing imperative to declare climate change a PHEIC, with Tedros Adhanom Ghebreyesus, director-general of WHO, declaring: "The climate crisis is a health crisis, fuelling outbreaks, contributing to higher rates of noncommunicable diseases, and threatening to overwhelm our health workforce and health infrastructure". Importantly, the health sector, perhaps more than other sectors, has successfully overcome formidable, vested interests in combatting these threats to health. CONCLUSION: It is thus imperative that WHO make full use of their credibility and influence to establish a global framework for the control of greenhouse gases through the declaration of excess greenhouse gas emissions as a hazardous substance, and declaring climate change a PHEIC. Who else is better placed to drive the considerable societal transformation needed to secure a liveable future?

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.

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.

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.