Investigating the effect of sex, maturity, training status, and physical activity on performance and health-related parameters in children, adolescents, and adults

In 2018, 48% of young people in Wales engaged in sport ≥3 times a week. However, questions remain regarding the influence of sex and maturation on aerobic and anaerobic trainability. Indeed, many earlier studies failed to appropriately account for physical activity (PA), confounding the interpretation of training per se. Moreover, there is a paucity of literature examining the long-term effects of training. Chapter 4 revealed that, irrespective of maturity, trained youth had a higher maximal oxygen uptake (V̇ O2max) than their untrained counterparts but, importantly, the magnitude of training-related difference was higher in girls than boys. Given the well-established sex-differences in the decline of PA levels with age, Chapter 5 explored the role of PA on V̇ O2max using compositional analyses. This demonstrated that, for the same change in PA, girls had a greater predicted change in absolute, and scaled, ̇ O2max. As the trainability, and kinetic determinants, of sprint performance have received little attention compared to aerobic fitness in youth, this was explored in Chapters 6 and 7. In Chapter 6, training was associated with a greater peak power and force, depending on maturity, with only post-pubertal participants demonstrating significant increases in performance. Using a repeated sprint protocol, mechanical efficiency was found to be more important than absolute force production for performance in Chapter 7, highlighting key training targets. Finally, using a narrative review and meta-analytical approach, Chapter 8 found significant inter-sport differences in all-cause, cardiovascular disease, and cancer mortality in former elite athletes, suggesting that sport type influences the long-term effects of training. Overall, this thesis highlights the distinct determinants of aerobic and anaerobic performance, with sex and maturity exerting different, and independent, effects. Moreover, the paucity of data available in girls was highlighted, with conclusions regarding the long-term effects of training in females largely precluded

Relocated tigers and relocated villagers: Ferality and human–animal entanglement in Indian conservation

This article will examine state intervention in the lives of tigers and people living in and around Panna Tiger Reserve in Madhya Pradesh, Central India. It explores how, over a decade after a reintroduction project rebuilt the tiger population from extinction and the central government launched a new compensation scheme to relocate villagers away from the national park, relocated tigers and not-yet relocated villagers resist and challenge conservation interventions to eradicate human life in Panna Tiger Reserve and (re)construct it as a wild tiger landscape. It will show how discourses of conservation and development that motivate state intervention seek to depoliticize and obfuscate programmes of control over human and tiger lives through their separation and purported ‘care’, contiguous with colonial policies and discursive practices that have intertwined the fate of wild animals and forest-dependent villagers in this part of India. In their feral subversions against these interventions, relocated tigers and not-yet relocated villagers expose the problematic contradictions and tensions that plague animal management, wildlife conservation, and rural development in India today. Based on 15 months of ethnographic fieldwork, the article draws on case studies and accounts from communities living around Panna Tiger Reserve to present alternatives to colonial and post-colonial discursive legitimizations of state intervention and control, revealing alternate understandings of the entanglement of humans and animals and the categories of ‘wild’ and ‘tame’

Engaging Conservation: Village-Forest Relations around Panna Tiger Reserve in Central India

This thesis explores the relationships between the Forest Department and local villagers around Panna Tiger Reserve, in Madhya Pradesh, Central India, where a successful reintroduction project has rebuilt the local tiger population following its extinction in 2009. Through an anthropological analysis of ‘village-forest relations’ the thesis asks what might be gained by focusing on ‘engagement’ alongside and beyond predominant narratives of exclusion and conflict between foresters and villagers in the literature on Indian conservation. Based on 15 months of ethnographic fieldwork spent living around the reserve, it explores the different ways in which the Forest Department and local people ‘engage’ with one another in public outreach, the enforcement of forest regulations, local employment and village relocation. I argue that village-forest relations, as a form of environmental politics, articulates the antagonistic vulnerabilities of ‘village’ and jungle and the state’s prioritisation of the latter. In each form of ‘engagement’, discourses of vulnerable, threatening villagers and vulnerable, threatened jungles legitimise state intervention to reify, separate and control both. At the same time, villagers assert and express their own vulnerability in livelihood, labour and citizenship to work around, negotiate and draw benefits from ‘village-forest relations’ and from relationships with other stakeholders in the landscape. I draw on a range of disciplines, including anthropology, environmental history, geography and political ecology, to interrogate and situate key concepts like vulnerability and engagement, speaking to broader discussions about politics, livelihoods, labour, development, bureaucracy and government in Indian conservation contexts. The thesis demonstrates the potential contribution of anthropologies of Indian politics and government to discussions about the impact of conservation on local populations. Finally, the thesis argues for approaches to conservation intervention that make use of the interdependent and locally situated character of village-forest relations towards more equitable outcomes for local people

Response to Comment on “Health Consequences of an Elite Sporting Career: Long-Term Detriment or Long-Term Gain? A Meta-Analysis of 165,000 Former Athletes”

IntroductionExercise is widely accepted to improve health, reducing the risk of premature mortality, cardiovascular disease (CVD) and cancer. However, several epidemiological studies suggest that the exercise-longevity relationship may be ‘J’ shaped; with elite athlete’s likely training above these intensity and volume thresholds. Therefore, the aim of this meta-analysis was to examine this relationship in former elite athletes.Methods38,047 English language articles were retrieved from Web of Science, PubMed and SportDiscus databases published after 1970, of which 44 and 24 were included in the systematic review and meta-analysis, respectively. Athletes were split into three groups depending on primary sport: Endurance (END), Mixed/Team, or power (POW). Standard mortality ratio’s (SMR) and standard proportionate mortality ratio (SPMR) were obtained, or calculated, and combined for the meta-analysis.ResultsAthletes lived significantly longer than the general population (male SMR 0.69 [95% CI 0.61–0.78]; female SMR 0.51 [95% CI 0.40–0.65]; both p < 0.01). There was no survival benefit for male POW athletes compared to the general population (SMR 1.04 [95% CI 0.91–1.12]). Although male athlete’s CVD (SMR 0.73 [95% CI 0.62–0.85]) and cancer mortality (SMR 0.75 [95% CI 0.63–0.89]), were significantly reduced compared to the general population, there was no risk-reduction for POW athletes CVD mortality (SMR 1.10 [0.86–1.40]) or END athletes cancer mortality (SMR 0.73 [0.50–1.07]). There was insufficient data to calculate female sport-specific SMR’s.DiscussionOverall, athletes live longer and have a reduced incidence of both CVD and cancer mortality compared to the general population, refuting the ‘J’ shape hypothesis. However, different health risks may be apparent according to sports classification, and between sexes, warranting further investigation

Impact of the COVID-19 Pandemic on Sedentary Time and Behaviour in Children and Adults: A Systematic Review and Meta-Analysis

The aim of this meta-analysis was to quantify the change in sedentary time during the COVID-19 pandemic and its effect on health outcomes in the general population. One thousand six hundred and one articles published after 2019 were retrieved from five databases, of which 64 and 40 were included in the systematic review and meta-analysis, respectively. Studies were grouped according to population: children (65 years). Average sedentary time was calculated, with sub-analyses performed by country, behaviour type and health outcomes. Children were most affected, increasing their sedentary time by 159.5 ± 142.6 min day−1, followed by adults (+126.9 ± 42.2 min day−1) and older adults (+46.9 ± 22.0 min day−1). There were no sex differences in any age group. Screen time was the only consistently measured behaviour and accounted for 46.8% and 57.2% of total sedentary time in children and adults, respectively. Increases in sedentary time were negatively correlated with global mental health, depression, anxiety and quality of life, irrespective of age. Whilst lockdown negatively affected all age groups, children were more negatively affected than adults or older adults, highlighting this population as a key intervention target. As lockdowns ease worldwide, strategies should be employed to reduce time spent sedentary. Trial registration: PROSPERO (CRD42020208909

Moving Forward: Understanding Correlates of Physical Activity and Sedentary Behaviour during COVID-19—An Integrative Review and Socioecological Approach

Population-level physical activity (PA) and sedentary time/behaviour estimates represent a significant public health issue exacerbated by restrictions enforced to control COVID-19. This integrative review interrogated available literature to explore the pandemic's impact on correlates of such behaviours in adults (≥18 years). Five electronic databases were systematically searched in January 2021. Data extracted from 64 articles were assessed for risk-of-bias using the Mixed Methods Assessment Tool, with correlates identified, coded, and themed via thematic analysis. A socioecological model of during-pandemic PA was conceptualized and mapped to the Capability, Opportunity, Motivation, and Behaviour (COM-B) model of behaviour change mechanisms, which illustrates influences over five levels: Individual (biological)-general health; Individual (psychological)-mental health, cognition, motivation, and behaviour; Social-domestic situation, sociodemographic factors, support, and lifestyle choices; Environmental-resources and area of residence; and Policy-COVID-19-related rules. For sedentary time/behaviour, individual level factors, namely general and mental health, may be important correlates. Neither age or sex were clearly correlated with either behaviour. As we transition into a new normal, understanding which behaviour mechanisms could effectively challenge physical inactivity is essential. Targeting capability on a psychological level may facilitate PA and limit sedentary time/behaviour, whereas, on a physical level, maximizing PA opportunities could be crucial

The effect of sex, maturity, and training status on maximal sprint performance kinetics

Purpose: The development of sprint running during youth has received renewed interest, but questions remain regarding the development of speed in youth, especially the influences of sex, training, and maturity status. Methods: One hundred and forty-seven team sport trained (69 girls; 14.3 [2.1] y) and 113 untrained (64 girls; 13.8 [2.7] y) youth completed two 30-m sprints separated by 2-minute active rest. Velocity was measured using a radar gun at >46 Hz, with power and force variables derived from a force–velocity–power profile. Results: Boys produced a significantly higher absolute peak power (741 [272] vs 645 [229] W; P < .01) and force (431 [124] vs 398 [125] N; P < .01) than girls, irrespective of maturity and training status. However, there was a greater sex difference in relative mean power and peak velocity in circa peak height velocity adolescents (46.9% and 19.8%, respectively) compared with prepeak height velocity (5.4% and 3.2%) or postpeak height velocity youth (11.6% and 5.6%). Conclusions: Sprint development in youth is sexually dimorphic which needs considering when devising long-term training plans. Further research is needed to explore the independent, and combined, effects of sex, training, and maturity status on sprint performance kinetics in youth

Effects of Sex, Training, and Maturity Status on the Cardiopulmonary and Muscle Deoxygenation Responses during Incremental Ramp Exercise

Whilst participation in regular exercise and sport has generally increased over recent decades globally, fundamental questions remain regarding the influence of growth, maturation, and sex on the magnitude of training response throughout adolescence. Trained (108 participants, 43 girls; age: 14.3 ± 1.8 years) and untrained (108 participants, 43 girls; age: 14.7 ± 1.7 years) adolescents completed an incremental ramp test to exhaustion during which breath by gas exchange, beat-by-beat heart rate (HR), stroke volume (SV) and cardiac output (Q·) and muscle deoxygenation were assessed. Device-based physical activity was also assessed over seven consecutive days. Boys, irrespective of training status, had a significantly higher absolute (2.65 ± 0.70 L min−1 vs. 2.01 ± 0.45 L min−1, p < 0.01) and allometrically scaled (183.8 ± 31.4 mL·kg−b min−1 vs. 146.5 ± 28.5 mL·kg−b min−1, p < 0.01) peak oxygen uptake (V·O2) than girls. There were no sex differences in peak HR, SV or Q· but boys had a higher muscle deoxygenation plateau when expressed against absolute work rate and V·O2 (p < 0.05). Muscle deoxygenation appears to be more important in determining the sex differences in peak V·O2 in youth. Future research should examine the effects of sex on the response to different training methodologies in youth