Grant Tomkinson

University of South Australia | UniSA · Allied Health and Human Performance

Background Handgrip strength (HGS) is an excellent marker of general strength capacity and health among adults. We aimed to calculate temporal trends in HGS for adults from Shanghai between 2000 and 2020. Methods Adults aged 20–59 years from Shanghai, China, were included. Representative cross-sectional HGS data (n = 127,756) were collected in 200...

Background Static stretching is widely used to increase flexibility. However, there is no consensus regarding the optimal dosage parameters for increasing flexibility. Objectives We aimed to determine the optimal frequency, intensity and volume to maximise flexibility through static stretching, and to investigate whether this is moderated by muscl...

Background Physical fitness is an excellent marker of general health and performance. We aimed to calculate trends in physical fitness among Lithuanian adolescents between 1992 and 2022. Methods Using a repeated cross-sectional design, body size and physical fitness data for 17 918 Lithuanian adolescents (50.3% female) aged 11–17 years were collec...

Background: Physical fitness in childhood and adolescence is associated with a variety of health outcomes and is a powerful marker of current and future health. However, inconsistencies in tests and protocols limit international monitoring and surveillance. The objective of the study was to seek international consensus on a proposed, evidence-infor...

Norm-referenced tests compare individuals to a group. While norms are often presented in tables and graphs, exact score evaluation relies on model parameters, often undisclosed. These models, like those from the R gamlss package, include individual data protected by law and consent, hindering full transparency. Thus, this paper proposes standards f...

Background Unfavourable changes occur in children’s health behaviours and outcomes during the summer holidays. This systematic review aimed to determine the effectiveness of summer holiday programs in mitigating these changes. Methods Six databases (MEDLINE, JBI, PsychINFO, Embase, ERIC and Scopus) were systematically searched for experimental con...

Kieser, J, Langford, M, Stover, E, Tomkinson, GR, Clark, BC, Cawthon, PM, and McGrath, R. Absolute agreement between subjective hand squeeze and objective handgrip strength in adults. J Strength Cond Res 39(1): 16-23, 2025-Despite handgrip strength (HGS) being considered a convenient muscle strength assessment, HGS lacks routine measurement in spor...

Background. Physical fitness (PF), an important marker of health and well-being, is influenced by a multitude of factors. This study aimed to quantify the associations of social environment factors with different aspects of PF among schoolchildren. Methods. Participants of this cross-sectional study were apparently healthy adolescents aged 11–18 ye...

Physical activity (PA) promotes better cardiometabolic health, physical function, brain health and longevity. In contrast, prolonged sedentary behaviour (SB) is a risk factor for many chronic diseases and poor health. Limited research has evaluated or synthesised how competitive sports participation influences PA across the lifespan. Some evidence...

Background The purpose of this study was to evaluate the associations of (1) individual absolute and body size normalized weakness cut-points, and (2) the collective weakness classifications on time to diabetes in Americans. Methods We analyzed data from 9577 adults aged at least 50-years from the Health and Retirement Study. Diabetes diagnosis wa...

Surveillance of health-related physical fitness can improve decision-making and intervention strategies promoting health for children and adolescents. However, no study has comprehensively analyzed surveillance/monitoring systems for physical fitness globally. This review sought to address this gap by identifying: (1) national-level surveillance/mo...

INTRODUCTION & AIMS The complex nature of children’s and adolescents’ participation in physical activity (PA) makes it difficult to measure. Questions have been used in Australia for many decades to subjectively monitor PA and sedentarism, however there is no consensus on which are the best. Since better data is needed to more accurately determine...

Background Cardiorespiratory fitness (CRF) is a strong marker of current and future health. The aim of this study was to assess the national temporal trends in CRF for French children and adolescents between 1999 and 2022. Methods CRF data were obtained from several cross‐sectional studies on 15 420 (51.1% boys) French children and adolescents age...

McGrath, R, McGrath, BM, Jurivich, D, Knutson, P, Mastrud, M, Singh, B, and Tomkinson, GR. Collective weakness is associated with time to mortality in Americans. J Strength Cond Res XX(X): 000–000, 2024—Using new weakness cutpoints individually may help estimate time to mortality, but their collective use could improve value. We sought to determine...

Objective To examine and summarise evidence from meta-analyses of cohort studies that evaluated the predictive associations between baseline cardiorespiratory fitness (CRF) and health outcomes among adults. Design Overview of systematic reviews. Data source Five bibliographic databases were searched from January 2002 to March 2024. Results From...

Background Weakness can be operationalized with several thresholds, which in turn, could impact associations with cognitive impairment when considering obesity status. Objective We examined the associations of absolute, normalized, and collective weakness thresholds on future cognitive impairment by obesity status in older adults. Methods We perf...

Background Cardiorespiratory fitness (CRF) is an important indicator of current and future health. While the impact of habitual physical activity on CRF is well established, the role of sedentary behaviour (SB) remains less understood. Objective We aimed to determine the effect of SB on CRF. Methods Searches were conducted in MEDLINE, Embase, Psy...

To quantify the tracking of apolipoprotein B (apoB) levels from childhood and adolescence and compare the tracking of apoB with low-density lipoprotein (LDL) cholesterol, a systematic search of MEDLINE, Embase, Web of Science, and Google Scholar was performed in October 2023 (PROSPERO protocol: CRD42022298663). Cohort studies that measured tracking...

Objectives: The aim of this study was to developed sex- and age-specific normative-referenced percentile values for health-related fitness among 12 to 18 years old Czech youth. Methods: This study included cross-sectional data from 1,173 participants (50.7% boys) collected between 2013 and 2016. Participants were recruited from 32 elementary or sec...

Background Emerging evidence suggests that children’s fatness increases and fitness declines at a greater rate during the summer holiday period, compared with the school year. The aim of this study was to compare rates of change in fitness and fatness over the in-term and summer holiday periods among Australian schoolchildren. A secondary aim was t...

Background Optimizing childhood domain-specific physical activity (PA) and sedentary behavior (SB) for blood lipid profile is not well understood. We aimed to (1) determine the associations between accelerometer-measured PA and SB for each domain (school time and out-of-school time) with blood lipid profile and (2) estimate predicted changes in blo...

Background Recently developed absolute and body size normalized handgrip strength (HGS) cut-points could be used individually and collectively to predict mobility problems and falls. Aims We examined the associations of (1) each absolute and normalized weakness cut-point, (2) collective weakness categories, and (3) changes in weakness status on fu...

Aim: Determine if asymmetric handgrip strength exists in childhood and adulthood and quantify the degree of tracking of handgrip strength asymmetry over time. Methods: Participants from the Childhood Determinants of Adult Health Study had their right and left handgrip strength measured using handgrip dynamometry in childhood (1985: 9-15y), young...

Objectives: New absolute and normalized handgrip strength (HGS) cut-points may not yield similar predictive value for cognitive performance. We sought to determine the associations of (1) each absolute and normalized weakness cut-point, and (2) compounding weakness on future cognitive impairment in older Americans. Design: Longitudinal panel. S...

Background: Strength asymmetries are a type of muscle function impairment that is associated with several health conditions. However, the prevalence of these asymmetries among adults from the United States remains unknown. We sought to estimate the prevalence and trends of handgrip strength (HGS) asymmetry in American adults. Methods: The unweig...

Humans have stepped on the Lunar surface for less than 80 hours of Extravehicular Activity, providing a narrow understanding of Lunar gait patterns. NASA’s Human-crewed Artemis missions are quickly approaching; understanding how fractional gravity affects gait patterns will be critical for the Moon's and Mars' long-term habitation. This study exami...

We used a prevalence-based approach to estimate the economic costs associated with low muscle strength, as assessed using handgrip strength, in Canadian adults. We estimated the annual economic burden of low muscle strength at $3.0 billion, representing 2.2% of the 2021 Canadian burden of illness costs. The two most expensive chronic diseases attri...

Background Instrumental activities of daily living (IADL) are neuropsychological-driven tasks that are linked to cognitive dysfunction. Examining population-based IADL deficits may reveal insights for the presence of these impairments in the United States. Objective This investigation sought to evaluate the prevalence and trends of IADL impairment...

Background Evidence shows children gain more weight during the summer holidays versus the school year. Objectives To examine within‐child differences in activity and diet behaviours during the summer holidays versus the school year. Methods Children (mean age 9.4 years; 37% male) wore accelerometers (GENEActiv; n = 133), reported activities (Mult...

The objective of this study was to estimate health care and health-related productivity costs associated with low cardiorespiratory fitness (CRF) in Canadian adults. We also estimated costs that would be avoided by a 10 percentage point prevalence reduction in low CRF. A prevalence-based approach was used to estimate the economic costs associated w...

Objectives: (1) To develop reference values for health-related fitness in European children and adolescents aged 6–18 years that are the foundation for the web based, open-access and multi-language fitness platform (FitBack); (2) To provide comparisons across European countries. Methods: This study builds on a previous large fitness reference stud...

Cardiorespiratory endurance (CRE) is an important health marker. The aim of this study was to examine temporal trends of CRE performance for Italian children between 1984 and 2010. Using a repeated cross-sectional study design, 5303 CRE test results were available for 2520 children aged 11-13 years from a single Northern Italian middle-high school...

Background: The primary aim was to examine the temporal trends in physical fitness (PF) for Japanese children and adolescents before and during the coronavirus disease (COVID-19) pandemic. The secondary aim was to estimate the concurrent trends in body size (measured as body mass and height) and movement behaviors (exercise, screen, and sleep time...

Background Past Physical Activity Report Cards have indicated a minority of Australian children and young people are sufficiently active. The purpose of this paper is to summarise grades across 10 indicators of the 2022 Australian Physical Activity Report Card, to assess physical activity behaviours and supports. Methods A development team consist...

Background The measurement of physical fitness has a history that dates back nearly 200 years. Recently, there has been an increase in international research and surveillance on physical fitness creating a need for setting international priorities that could help guide future efforts. Objective This study aimed to produce a list of the top 10 inte...

Background: Evidence regarding the impact of parenting style on health and other outcomes is inconsistent and limited by measurement quality and type. This study will examine associations between parenting style and children's objectively assessed activity patterns, body composition, fitness, diet, health, and academic achievement. Methods: Two hun...

There was a mistake in this paper, and it will be corrected.

Background Few studies have investigated the optimal anthropometric index associated with potential cardio-metabolic risk. Using direct measures of standing height, body mass, and waist circumference, we sought to identify the optimal index for detecting cardio-metabolic risk associated with diabetes and hypertension in a nationally representative...

Objectives (1) To develop reference values for health-related fitness European children and adolescents aged 6–18 years that are the foundation for the web-based, open-access and multi-language fitness platform (FitBack); (2) To provide comparisons across European countries. Methods This study builds on a previous large fitness reference study in...

Physical fitness (PF) is significantly associated with current and future health. Routine assessment of PF is important not only to understand the overall health of the population, but also to predict future disease burden. While the annual national PF testing conducted by the Japan Sports Agency is well known domestically, the existence of this su...

Background Little is known about which indicators of performance elite athlete coaches (i.e., professional coaches who coach at the national or international levels) consider to be important for basketball. Objective Using a Delphi procedure, the aim of this study was to identify the non-game performance indicators elite athlete coaches consider t...

Introduction: Handgrip strength (HGS) asymmetry may help identify the functional asymmetries that contribute to mobility limitations. We sought to determine the associations of HGS asymmetry on gait speed and standing balance in older Americans. Materials and Methods: The analytic sample included 8,396 adults aged ≥65-years for the last wave in whi...

Handgrip dynamometers are widely used to measure handgrip strength (HGS). HGS is a safe and easy to obtain measure of strength capacity, and a reliable assessment of muscle function. Although HGS provides robust prognostic value and utility, several protocol variants exist for HGS in clinical settings and translational research. This lack of method...

Low physical fitness in adolescence is linked with increased cardiometabolic risk and early all-cause mortality. This study aimed to estimate temporal trends in the physical fitness of Hong Kong adolescents aged 12–17 years between 1998 and 2015. Physical fitness (9-min run/walk, sit-ups, push-ups, and sit-and-reach) and body size data in a total o...

Background: The fitness levels of Canadian adults declined substantially between 1981 and the years 2007 to 2009, suggesting a reduction in population health. This paper updates the fitness trends of Canadians aged 20 to 69 years by extending the time period to 2017. Data and methods: The Canadian Health Measures Survey is a repeated cross-secti...

Potter, NJ, Tomkinson, GR, Dufner, TJ, Walch, TJ, Roemmich, JN, Wilson, PB, and Fitzgerald, JS. Effects of exercise training on resting testosterone concentrations in insufficiently active men: a systematic review and meta-analysis. J Strength Cond Res 35(12): 3521-3528, 2021-The anabolic hormone testosterone plays a pivotal role in the healthy agi...

Aim To determine how anthropometric characteristics cluster in the New Zealand Defence Force, and to describe the characteristics of each cluster. This information can inform the development of new uniform sizing systems for the New Zealand Defence Force. Methods Anthropometric data (n = 84 variables) from 1,003 participants (212 females; 791 male...

This study examined the associations between asymmetric handgrip strength (HGS) and multimorbidity in American adults. Secondary analyses of data from persons aged at least 40 years from the 2011–2012 and 2013–2014 waves of the National Health and Nutrition Examination Survey were conducted. A handheld dynamometer collected HGS on each hand and per...

Background Digit ratio (2D:4D), a putative marker of prenatal testosterone, is a negative correlate of sports, athletic, and fitness performance. Objectives To describe the relationship between 2D:4D and vertical jump performance in athletes. Methods Sixty-one Division I American Football players from a Midwestern U.S. university had their 2D:4D...

Aim To determine how well decision tree models can predict tailor-assigned uniform sizes using anthropometry data from the New Zealand Defence Force Anthropometry Survey (NZDFAS). This information may inform automatic sizing systems for military personnel. Methods Anthropometric data from two separate samples of the New Zealand Defence Force milit...

Background Cardiorespiratory fitness (CRF), which reflects the overall aerobic capacity of the cardiovascular, respiratory, and muscular systems, is significantly related to health among youth.Objective The aim of this systematic review was to identify health-related criterion-referenced cut-points for CRF among youth aged 5–17 years.MethodsA syste...

Introduction: Handgrip strength (HGS) is an important indicator of health. Because HGS is strongly associated with body size, most investigators normalize HGS for some measure of body size as a more sensitive indicator of strength within a population. We aimed to (1) identify the optimal body size dimension to remove (normalize) HGS for difference...

Background Musculoskeletal fitness is an excellent functional measure that is significantly related to health among youth. Objective Our objective was to identify health-related criterion-referenced cut-points for musculoskeletal fitness (MSF) among youth. Methods A systematic search of two electronic databases (MEDLINE and SPORTDiscus) was condu...

Background and objectives: Doubts have been raised concerning the validity of the 20-m shuttle-run test (20 mSRT) as a predictor of cardiorespiratory fitness (CRF) in youth based on Léger's equation/model. An alternative allometric model has been published recently that is thought to provide, not only a superior fit (criterion validity) but also a...

Background /Objective: Cardiorespiratory endurance is an excellent marker of functional endurance and health among adults. The aim of this study was to estimate temporal trends in step test performance for Chinese adults between 2000 and 2014. Methods Apparently healthy adults aged 20–59 years were included. Nationally representative step test dat...

Background Digit ratio (2D:4D), a marker of prenatal testosterone exposure, is a weak negative correlate of sports/athletic/fitness performance. While numerous studies have examined the relationship between 2D:4D and physical fitness, there has never been a comprehensive study that has synthesized studies examining relationships between 2D:4D and m...

Background: Physical inactivity during the COVID-19 pandemic is a public health concern for older adults. Telehealth presents a safe platform for conducting health-related interventions that may have additional benefits such as widespread reach. Our pilot study sought to examine how a telehealth intervention changed activity profiles in older adul...

Background/Objective Physical function, the ability of an individual to carry out physical tasks, is meaningfully related to health among older adults. Few studies have analyzed temporal trends in objective performance measures of physical function for older adults. The aim of this study was to estimate temporal trends in balance and walking speed...

Maximal handgrip strength (HGS) is a convenient and reliable, but incomplete, assessment of muscle function. Although low HGS is a powerful predictor of poor health, several limitations to maximal HGS exist. The predictive value of HGS is restricted because low HGS is associated with a wide range of unspecified health conditions, and other characte...