Papers by Kelly Mackintosh
Sports Medicine, Sep 11, 2023
Background Movement quality is typically assessed by drawing comparisons against predetermined mo... more Background Movement quality is typically assessed by drawing comparisons against predetermined movement standards. Movements are often discretely scored or labelled against pre-set criteria, though movement quality can also be evaluated using motion-related measurements (e.g., spatio-temporal parameters and kinematic variables). Wearable technology has the potential to measure and assess movement quality and offer valuable, practical feedback. Objectives A systematic approach was taken to examine the benefits associated with multi-sensor and multiple wearabledevice usage, compared with unimodal applications, when assessing movement quality. Consequently, this review considers the additional variables and features that could be obtained through multi-sensor devices for use in movement analyses. Processing methods and applications of the various configurations were also explored. Methods Articles were included within this review if they were written in English, specifically studied the use of wearable sensors to assess movement quality, and were published between January 2010 and December 2022. Of the 62,635 articles initially identified, 27 papers were included in this review. The quality of included studies was determined using a modified Downs and Black checklist, with 24/27 high quality. Results Fifteen of the 27 included studies used a classification approach, 11 used a measurement approach, and one used both methods. Accelerometers featured in all 27 studies, in isolation (n = 5), with a gyroscope (n = 9), or with both a gyroscope and a magnetometer (n = 13). Sampling frequencies across all studies ranged from 50 to 200 Hz. The most common classification methods were traditional feature-based classifiers (n = 5) and support vector machines (SVM; n = 5). Sensor fusion featured in six of the 16 classification studies and nine of the 12 measurement studies, with the Madgwick algorithm most prevalent (n = 7). Conclusions This systematic review highlights the differences between the applications and processing methods associated with the use of unimodal and multi-sensor wearable devices when assessing movement quality. Further, the use of multiple devices appears to increase the feasibility of effectively assessing holistic movements, while multi-sensor devices offer the ability to obtain more output metrics. Wearable technology has been widely used in research to measure and classify matters relating to movement quality using an array of machine-learning and sensor-fusion methods. Multiple multimodal sensor devices appear to be more effective than single multimodal sensor devices when assessing holistic movements. Devices containing multiple sensors offer the ability to obtain more output metrics than those featuring just one sensor.
Pediatric Exercise Science, 2022
Purpose; Understanding which physical activity (PA) and sedentary behaviour correlates cluster in... more Purpose; Understanding which physical activity (PA) and sedentary behaviour correlates cluster in children is important, particularly in the home, where children spend significant time. Therefore, this study aimed to assess clustering of social and physical activity-related factors at home, and whether these clusters are related to home-based sitting and PA in children. A secondary aim was to explore whether the clusters were associated with child, parent and family characteristics. Methods; Altogether, 235 children (55% girl, mean age = 10.2 ± 0.7 years) and their parents took part. Physical (e.g., PA and electronic media equipment, house and garden size, layout) and social (e.g., activity preferences, priorities, parental rules) home environmental factors were obtained via the HomeSPACE-II audit and self-report, respectively. Principal component analysis (PCA) was used to identify clusters of physical and social environmental factors. Backward regression analysis and partial correlations were used to examine relationships between clusters, children's (55% girl, mean age = 10.2 ± 0.7 years) device-measured homebased activity behaviours and background characteristics. The findings show that physical and social environment activity-related factors at home cluster. The clusters were associated with several background characteristics, with socioeconomic factors appearing to be particularly influential. The clusters were also associated with home-based activity behaviours in the hypothesised directions. Clustering of environmental factors in the home Conclusion; Interventions which target clusters of social and physical factors at home, especially among low-socioeconomic status (SES) families, are warranted.
Journal of Sports Sciences, Oct 19, 2019
The aim of this study was to investigate deprivation and sex differences in selected health-relat... more The aim of this study was to investigate deprivation and sex differences in selected health-related fitness measures in 9-12-year-old children. Data were captured on 3,407 children (49.3% boys; aged 10.5±0.6 years) as part of the serial Swan-Linx programme between 2013-2017. Three components of health-related fitness were measured, namely cardiorespiratory fitness (20m multistage shuttle run test; 20m MSRT), muscular strength (handgrip strength) and body mass index (stature and body mass; BMI). Participants' home postcodes were used to calculate Welsh Index of Multiple Deprivation (WIMD) scores, and to split participants into quintile groups. A two-way Analysis of Variance examined differences in BMI z-score by sex and WIMD quintiles. Two-way Analysis of Covariances investigated the effect of sex and WIMD quintiles on grip strength, adjusting for BMI zscore, and on shuttles achieved in the 20m MSRT, adjusting for maturation. Independent of sex, children in the middle quintile had a significantly higher mean BMI z-score (p=0.029) than their least deprived counterparts. There was a significant increase in grip strength (p=0.005) and 20m MSRT (boys p<0.001; girls p=0.028) between most and least deprived quintiles. Significant differences in 20m MSRT score were more apparent with decreases in deprivation in boys. The present study was one of the first large-scale studies to investigate differences in BMI, muscular strength and cardiorespiratory fitness by sex and different levels of deprivation. Overall, results showed that inequalities exist and should be used to inform focused services and interventions to improve current and future health inequalities.
Lecture Notes in Computer Science, 2015
Physical Activity is important for maintaining healthy lifestyles. Recommendations for physical a... more Physical Activity is important for maintaining healthy lifestyles. Recommendations for physical activity levels are issued by most governments as part of public health measures. As such, reliable measurement of physical activity for regulatory purposes is vital. This has lead research to explore standards for achieving this using wearable technology and artificial neural networks that produce classifications for specific physical activity events. Applied from a very early age, the ubiquitous capture of physical activity data using mobile and wearable technology may help us to understand how we can combat childhood obesity and the impact that this has in later life. A supervised machine learning approach is adopted in this paper that utilizes data obtained from accelerometer sensors worn by children in free-living environments. The paper presents a set of activities and features suitable for measuring physical activity and evaluates the use of a Multilayer Perceptron neural network to classify physical activities by activity type. A rigorous reproducible data science methodology is presented for subsequent use in physical activity research. Our results show that it was possible to obtain an overall accuracy of 96% with 95% for sensitivity, 99% for specificity and a kappa value of 94% when three and four feature combinations were used.
Pediatric Pulmonology, Dec 8, 2020
Purpose: Physical activity (PA) and sleep are highly important for those with Cystic Fibrosis (CF... more Purpose: Physical activity (PA) and sleep are highly important for those with Cystic Fibrosis (CF), yet, despite this and suggestions of a bidirectional relationship between these factors in healthy children, their relationship is yet to be investigated. Methods: PA, sedentary time (SED) and sleep were objectively derived over seven days in 58 youth (11.9±2.7 years; 29 CF). Generalized linear latent and mixed models with a random intercept and slope at child-level were adjusted for age, sex, wear-time, type of day, group and mean PA/SED and sleep. Results: Every additional 10 mins sedentary was associated with 5.6 and 5.0 mins less sleep and 10.6 and 12.0 mins less wake after sleep onset (WASO) that night, in CF and healthy children, respectively. PA, regardless of intensity, was not associated with total sleep time but every additional 10 mins of light PA (LPA) was associated with 3.0 mins less WASO in healthy participants. Ten mins more sleep was associated with 3.1 and 1.7 mins less SED in CF and healthy children, respectively. In CF, greater sleep time led to less LPA (3.6 mins) the following day, whereas, in healthy children, poor sleep quality (greater WASO) was associated with more LPA (1.4 mins) and moderate-to-vigorous PA (5.2 mins) the following day. A bidirectional relationship between SED and subsequent total sleep time was evident, irrespective of group, whereas the relationship between sleep and PA was group dependent. These findings have important implications regarding the reciprocal effects of promoting PA or sleep quantity or quality.
Physiological Measurement, Sep 30, 2019
Sampling rate (Hz) of ActiGraph accelerometers may affect processing of acceleration to activity ... more Sampling rate (Hz) of ActiGraph accelerometers may affect processing of acceleration to activity counts when using a hip-worn monitor, but research is needed to quantify if sampling rate affects actual acceleration (mg's), when using wrist-worn accelerometers and during non-locomotive activities. Objective: To assess the effect of ActiGraph sampling rate on total counts/15-sec and mean acceleration and to compare differences due to sampling rate between accelerometer wear locations and across different types of activities. Approach: Children (n=29) wore a hip-and wrist-worn accelerometer (sampled at 100 Hz, downsampled in MATLAB to 30 Hz) during rest/transition periods, active video games, and a treadmill test to volitional exhaustion. Mean acceleration and counts/15-sec were computed for each axis and as vector magnitude. Main Results: There were mostly no significant differences in mean acceleration. However, 100 Hz data resulted in significantly more total counts/15-sec (mean bias 4-43 counts/15-sec across axes) for both the hip-and wrist-worn monitor when compared to 30 Hz data. Absolute differences increased with activity intensity (hip: r=0.46-0.63; wrist: r=0.26-0.55) and were greater for hipversus wrist-worn monitors. Percent agreement between 100 and 30 Hz data was high (97.4-99.7%) when cut-points or machine learning algorithms were used to classify activity intensity. Significance: Our findings support that sampling rate affects the generation of counts but adds that differences increase with intensity and when using hip-worn monitors. We recommend researchers be consistent and vigilantly report the sampling rate used, but note that classifying data into activity intensities resulted in agreement despite differences in sampling rate.
Journal for the measurement of physical behaviour, Dec 1, 2021
ActiGraph is a commonly used, research-grade accelerometer brand, but there is little information... more ActiGraph is a commonly used, research-grade accelerometer brand, but there is little information regarding inter-monitor comparability of newer models. Additionally, whilst sampling rate has been shown to influence accelerometer metrics, its influence on measures of free-living physical activity has not been directly studied. Purpose: To examine differences in physical activity metrics due to inter-monitor variability and chosen sampling rate. Methods: Adults (n=20) wore two hip-worn ActiGraph wGT3X-BT monitors for one week, with one accelerometer sampling at 30 Hz and the other at 100 Hz, which was downsampled to 30 Hz. Activity intensity was classified using vector magnitude (VM), Euclidean Norm Minus One (ENMO), and Mean Amplitude Deviation (MAD) cut-points. Equivalence testing compared outcomes. Results: There was a lack of inter-monitor equivalence for ENMO, time in sedentary/light-or moderate-intensity activity according to ENMO cut-points, and time in moderate-intensity activity according to MAD cut-points. Between sampling rates, differences existed for time in moderate-intensity activity according to VM, ENMO and MAD cut-points, and time in sedentary/light-intensity activity according to ENMO cut-points. While mean differences were small (0.1-1.7 percentage points), this would equate to differences in moderateto-vigorous-intensity activity over a 10-h wear-day of 3.6 (MAD) to 10.8 (ENMO) min•day -1 for inter-monitor comparisons or 3.6 (VM) to 5.4 (ENMO) min•day -1 for sampling rate. Conclusions: Epoch-level inter-monitor differences were larger than differences due to sampling rate, but both may impact outcomes such as time spent in each activity intensity. ENMO was the least comparable metric between monitors or sampling rates.
International Journal of Environmental Research and Public Health, Jan 18, 2022
Novel coronavirus disease 2019 (COVID-19) pandemic restrictions have negatively impacted physical... more Novel coronavirus disease 2019 (COVID-19) pandemic restrictions have negatively impacted physical activity (PA) and sedentary time/behaviour. This integrative review systematically explored the socioecological factors that impacted and influenced these movement behaviours in children and adolescents during the pandemic. Five electronic databases were systematically searched in January 2021, with data extracted from 16 articles (n = 18,352; 5-17 years; 12 countries). Risk-of-bias was assessed using the Mixed Methods Assessment Tool (MMAT), with correlates identified, coded, and themed via thematic analysis. A socioecological model of during-pandemic PA and sedentary time/behaviour was conceptualised and mapped to the Capability, Opportunity, Motivation, and Behaviour (COM-B) model of behaviour-change mechanisms, illustrating influences over five levels: Individual (biological)-age and sex; Individual (psychological)-mental health, and cognition, motivation, and behaviour; Social-family factors, and structured support; Environmental-area of residence and resources; and Policy-COVID-19-related rules. For sedentary time/behaviour, individual-(age and sex), social-(family factors) and policy-(COVID-19-related rules) level factors may be important correlates. There were no age or sex associations with PA levels, though there was some indication that sedentary time/behaviour increased with age. Interventions seeking to enhance young people's movement behaviours during periods of enforced restrictions should focus on enhancing opportunities on a social and environmental level.
HAL (Le Centre pour la Communication Scientifique Directe), 2021
-Developing interventions that target population-specific motivational barriers to promote health... more -Developing interventions that target population-specific motivational barriers to promote health behaviours is crucial, especially for older adults who are confronted with negative age stereotypes. This systematic review evaluates randomised and non-randomised field studies that tested the effects of age stereotype-based interventions on health outcomes, in adults aged 50 years and over. Methods -MEDLINE, SPORTDISCUS, Scopus, Web of Science Core Collection and PsychINFO were searched to identify articles published up until May 2019. Data were extracted from all articles independently and assessed for risk-of-bias using Cochrane Collaboration tools. Results -Ten articles met the inclusion criteria. Health-related outcome measures were identified across three domains: physical, psychological/psychosocial well-being, and quality of life/subjective health, with age stereotypes reported as an additional outcome. Intervention structure varied substantially between studies regarding content, duration, frequency, and length of follow-up. Conclusions -Most studies showed that age stereotype-based interventions significantly improved physical function or physical activity, as well as self-perceptions of ageing. However, more rigorous studies are needed. Indeed, given the detrimental health effects of age stereotypes, the potential for impact of interventions designed to challenge them is important. Future research should explore: the implications of intervening on different stereotype mechanisms; whether intervention effects are comparable across health domains; and whether age stereotype-based interventions are more effective than non-age-specific interventions. PROSPERO Registration CRD42018094006.
Journal of Science and Medicine in Sport, Oct 1, 2020
Objectives: This study aimed to quantify the relationships between enabling, predisposing and rei... more Objectives: This study aimed to quantify the relationships between enabling, predisposing and reinforcing ecological factors on motor competence and investigate potential sex, weight status, and school level differences. Methods: Data were collected from 429 children (52% boys; aged 11.1±0.6 years; 87% white British). Cardiorespiratory fitness (20m Multistage Shuttle Run), muscular strength (Handgrip Strength) and online questionnaire (Child Health and Activity Tool; CHAT) data on moderate-to-vigorous physical activity, sport participation and available surrounding physical activity facilities were included as enabling variables. Three predisposing variables were determined from self-report data on benefits/barriers to exercise, adequacy, and predilection. Parental/guardian physical activity levels and persons whom participate in physical activity and sport with the participant (CHAT) were selected as reinforcing variables. Motor competence was determined from cumulative scores for Dragon Challenge tasks (Balance Bench, Core Agility, Wobble Spot, Overarm Throw, Basketball Dribble, Catch, Jumping Patterns, T-Agility, Sprint). Confirmatory Factor Analysis assessed the fit of measured variables into latent factors. Structural equation modelling evaluated relationships between these latent factors. Results: Motor competence was directly affected by the enabling factor (β=0.50, p<0.001) but indirectly affected by reinforcing and predisposing factors, mediated by the enabling factor (β=0. 13, p=0.014; β=0.25, p=0.002). Multi-group comparisons showed that each of these effects did not differ by sex, weight status or school level (p>0.05). Conclusions: This study demonstrated that enabling factors are crucial for the development of motor competence. This is the first study to quantify an ecological model with motor competence as the endogenous variable and is key to future interventions.
Journal of Sports Sciences, May 26, 2019
Anaerobic performance in youth has received little attention partly due to the lack of a 'gold-st... more Anaerobic performance in youth has received little attention partly due to the lack of a 'gold-standard' measurement. However, force-velocity-power (F-v-P) profiling recently showed high reliability and validity in trained adults. Therefore, the aim was to determine the reliability of F-v-P profiling in children. Seventy-five children (60 boys, 15 girls; age: 14.1 ± 2.6 years) completed three 30 m sprints. Velocity was measured at 46.875 Hz using a radar device. The F-v-P profile was fitted to a velocity-time curve allowing instantaneous power variables to be calculated. Reliability was assessed using the intra-class correlation coefficient (ICC), coefficient of variation (CV), standard error of measurement (SEM) and smallest worthwhile change (SWC). High reliability was evident for absolute peak (Ppeak) and mean power (Pmean), Ppeak and Pmean expressed relative to body mass, peak and mean velocity, 30 m sprint time, peak horizontal force (F0), relative F0, mechanical efficiency index and fatigue rate (ICC: 0.75 -0.88; CV: 1.9 -9.4%) with time to peak power demonstrating moderate reliability (ICC: 0.50; CV: 9.5%). The F-v-P model demonstrated at least moderate reliability for all variables. This therefore provides a potential alternative for paediatric researchers assessing sprint performance and the underlying kinetics.
bioRxiv (Cold Spring Harbor Laboratory), Sep 25, 2022
The benefits of physical activity (PA) and the negative impacts of sedentary time (SED) on both s... more The benefits of physical activity (PA) and the negative impacts of sedentary time (SED) on both short-and long-term health in youth are well established. However, uncertainty remains about how PA and SED jointly influence maximal oxygen uptake (VȮ 2max ). Therefore, the aim of this study was to determine the joint influence of PA and SED on peak VȮ 2 using compositional analyses. 176 adolescents (84 girls, 13.8 ± 1.8 years) completed an incremental ramp test, and supramaximal validation bout, on cycle ergometer with PA and SED recorded for seven consecutive days on the right hip using a ActiGraph GT3X accelerometer. Time spent in sleep, SED, light, moderate and vigorous PA was analysed using a compositional linear regression model. Compositions with 10 minutes more time in vigorous PA (> 27.5 mins⋅day - 1 ) compared to the average 17.5 mins⋅day -1 were associated with a + 2.9% -11.1% higher absolute and allometrically scaled peak VȮ 2 . Whereas compositions with less (> -10 mins⋅day - 1 ) VPA were associated with a reduced absolute and allometrically scaled VȮ 2max (-4.6% -24.4%). All associations were irrespective of sex, maturity, and training status. The proportion of time spent sedentary had little impact on absolute and scaled peak VȮ 2 (0.01 -1.98%). These findings therefore highlight that intensity of PA may be of greater importance for increases in VȮ 2max than reductions in SED and should be incorporated into future intervention designs.
PLOS ONE, Aug 10, 2017
Recent studies have suggested that changing direction is associated with significant additional e... more Recent studies have suggested that changing direction is associated with significant additional energy expenditure. A failure to account for this additional energy expenditure of turning has significant implications in the design and interpretation of health interventions. The purpose of this study was therefore to investigate the influence of walking speed and angle, and their interaction, on energy expenditure in 20 healthy adults (7 female; 28±7 yrs). On two separate days, participants completed a turning protocol at one of 16 speed-(2.5, 3.5, 4.5, 5.5 kmÁh -1 ) and angle (0, 45, 90, 180˚) combinations, involving three minute bouts of walking, interspersed by three minutes seated rest. Each condition involved 5 m of straight walking before turning through the pre-determined angle with the speed dictated by a digital, auditory metronome. Tri-axial accelerometry and magnetometry were measured at 60 Hz, in addition to gas exchange on a breath-by-breath basis. Mixed models revealed a significant main effect for speed (F = 121.609, P < 0.001) and angle (F = 19.186, P < 0.001) on oxygen uptake ( _ V O 2 ) and a significant interaction between these parameters (F = 4.433, P < 0.001). Specifically, as speed increased, _ V O 2 increased but significant increases in _ V O 2 relative to straight line walking were only observed for 90˚and 180˚turns at the two highest speeds (4.5 and 5.5 kmÁhr -1 ). These findings therefore highlight the importance of accounting for the quantity and magnitude of turns completed when estimating energy expenditure and have significant implications within both sport and health contexts.
Jmir mhealth and uhealth, Nov 23, 2016
The proliferation and popularity of wearable activity trackers (eg, Fitbit, Jawbone, Misfit) may ... more The proliferation and popularity of wearable activity trackers (eg, Fitbit, Jawbone, Misfit) may present an opportunity to integrate such technology into physical activity interventions. While several systematic reviews have reported intervention effects of using wearable activity trackers on adults' physical activity levels, none to date have focused specifically on children and adolescents. Objective: The aim of this review was to examine the effectiveness of wearable activity trackers as a tool for increasing children's and adolescents' physical activity levels. We also examined the feasibility of using such technology in younger populations (age range 5-19 years). We conducted a systematic search of 5 electronic databases, reference lists, and personal archives to identify articles published up until August 2016 that met the inclusion criteria. Articles were included if they (1) specifically examined the use of a wearable device within an intervention or a feasibility study; (2) included participants aged 5-19 years old; (3) had a measure of physical activity as an outcome variable for intervention studies; (4) reported process data concerning the feasibility of the device in feasibility studies; and (5) were published in English. Data were analyzed in August 2016. In total, we identified and analyzed 5 studies (3 intervention, 2 feasibility). Intervention delivery ranged from 19 days to 3 months, with only 1 study using a randomized controlled trial design. Wearable activity trackers were typically combined with other intervention approaches such as goal setting and researcher feedback. While intervention effects were generally positive, the reported differences were largely nonsignificant. The feasibility studies indicated that monitor comfort and design and feedback features were important factors to children and adolescents. There is a paucity of research concerning the effectiveness and feasibility of wearable activity trackers as a tool for increasing children's and adolescents' physical activity levels. While there are some preliminary data to suggest these devices may have the potential to increase activity levels through self-monitoring and goal setting in the short term, more research is needed to establish longer-term effects on behavior.
Journal of Physical Activity and Health, Apr 1, 2022
Background: Population level changes in physical activity (PA) may benefit from policy interventi... more Background: Population level changes in physical activity (PA) may benefit from policy intervention. In response to the UN Sustainable Development Goals, Wales introduced legislation to holistically improve health and well-being, including Public Service Boards (PSBs) to improve the translation of national policy into practice. Method: An audit of policies published by national and sub-national public bodies since 2015 was conducted. Content of the policies were extracted and synthesised to determine: (i) how many policies included a PA action; (ii) what the drivers of those policies were; (iii) the content of the PA actions; and (iv) how the PA actions aligned with the Well-being of Future Generations (Wales) Act 2015. Results: 16 national-level documents with a PA action have been published by 4/13 public bodies. The policies vary in terms of the clarity and specificity of the actions, the assignment of clear roles/responsibilities, and the setting of targets. Of the 19 sub-national PSBs well-being policies, 15 included PA actions. This audit provides a valuable example of how connections between national and subnational policy can be achieved. The appointment of PSBs has supported the translation of policies into practice in Wales, and similar approaches could be utilised in other countries.
Pediatric Diabetes, Dec 5, 2021
like to thank Dr Chris Bidder and the clinical teams who facilitated and supported the study. ZM ... more like to thank Dr Chris Bidder and the clinical teams who facilitated and supported the study. ZM conceived the study, collected the data, performed data and statistical analysis, and drafted the manuscript; MAM conceived the study, aided with physical activity data and statistical analysis and drafting of the manuscript; KM conceived the study, aided physical activity data and statistical analysis and drafting of the manuscript, JWG assisted in the design of the study, supported data collection and drafting of the manuscript.
Medicine and Science in Sports and Exercise, Jan 21, 2020
This cross-sectional study aimed to: i) identify and characterize youth according to distinct phy... more This cross-sectional study aimed to: i) identify and characterize youth according to distinct physical activity (PA) and sedentary (SED) accumulation patterns; and ii) investigate associations of these derived patterns with cardiometabolic risk factors. : ActiGraph accelerometer data from 7-13 year olds from two studies were pooled (n=1,219; 843 [69%] with valid accelerometry included in analysis). Time accumulated in ≥5min and ≥10-min SED bouts, ≥1-min and ≥5-min bouts of light (LPA), and ≥1-min bouts of moderate (MPA) and vigorous (VPA) PA were calculated. Frequency of breaks in SED were also obtained. Latent profile analysis was used to identify groups of participants based on their distinct accumulation patterns. Linear and logistic regression models were used to test associations of group accumulation patterns with cardiometabolic risk factors, including adiposity indicators, blood pressure and lipids. Total PA and SED time were also compared between groups. Results: Three distinct groups were identified: 'Prolonged sitters' had the most time in prolonged SED bouts and the least time in VPA bouts; 'Breakers' had the highest frequency of SED breaks and lowest engagement in sustained bouts across most PA intensities; 'Prolonged movers' had the least time accumulated in SED bouts and the most in PA bouts across most intensities. 'Prolonged movers' and 'Breakers' had lower odds of being classified as overweight/obese based on body mass index compared to 'Prolonged sitters'. Whilst 'Breakers' engaged in less time in PA bouts compared to other groups, they had the healthiest adiposity indicators. No associations with the remaining cardiometabolic risk factors were found. The current results suggest that youth accumulate their daily activity in three distinct patterns ('Prolonged sitters', 'Breakers' and 'Prolonger movers'), with those breaking up sitting and most time in sporadic PA across the day having a lower adiposity risk. No relationships with other cardiometabolic risk factors were identified.
BMC Public Health, May 1, 2020
Background: High-intensity interval training (HIIT) elicits numerous health benefits, but little ... more Background: High-intensity interval training (HIIT) elicits numerous health benefits, but little evidence is available regarding the feasibility of delivering school-based HIIT interventions. The aim of this study was to explore adolescents' perceptions of a 6-month, 3 × 30-min sessions per week, HIIT intervention delivered either before or after school. Method: Eighty adolescents allocated to the intervention group (13.3 ± 1.0 years; 45 boys) were invited to take part in semi-structured focus groups post-intervention. Participants were categorised as attendees (≥40% attendance) or non-attendees (< 5% attendance). Data were transcribed verbatim and thematically analysed deductively, with key emergent themes represented using pen profiles. Results: Results showed that a school-based HIIT intervention can be an enjoyable form of exercise. Irrespective of attendance, similar facilitators and barriers to participating were highlighted, including benefits of participation, content of the exercise session and the intervention instructor. This study provides support for the delivery of a HIIT intervention in a school setting but highlights the importance of a flexible design and delivery to accommodate competing interests. There is a need to educate adolescents on the possible benefits of participation and to make the sessions enjoyable in order to increase their extrinsic and intrinsic motivation to sustain participation.
Journal of Sports Sciences, Nov 27, 2019
Although an association has been suggested between asthma, obesity, fitness and physical activity... more Although an association has been suggested between asthma, obesity, fitness and physical activity, the relationship between these parameters remains to be elucidated in adolescents. Six-hundred and sixteen adolescents were recruited (334 boys; 13.0±1.1years; 1.57±0.10m; 52.6±12.9kg), of which 155 suffered from mild-to-moderate asthma (78 boys). Participants completed a 20-metre shuttle run test, lung function and 7-day objective physical activity measurements and completed asthma control and quality of life questionnaires. Furthermore, 69 adolescents (36 asthma; 21 boys) completed an incremental ramp cycle ergometer test. Although participants with asthma completed significantly fewer shuttle runs than their peers, peak V ̇O2 did not differ between the groups. However, adolescents with asthma engaged in less physical activity (53.9±23.5 vs 60.5±23.6minutes) and had higher BMI (22.2±4.8 vs 20.4±3.7kg•m -2 ), than their peers. Whilst a significant relationship was found between quality of life and cardiorespiratory fitness according to peak V ̇O2, only BMI was revealed as a significant predictor of asthma status. The current findings highlight the need to use accurate measures of cardiorespiratory fitness rather than indirect estimates to assess the influence of asthma during adolescence. Furthermore, the present study suggests that BMI and fitness may be key targets for future interventions seeking to improve asthma quality of life.
Journal of Sports Sciences, Jul 18, 2019
Introduction: High-Intensity Interval Training (HIIT) and Constant-Intensity Endurance Training (... more Introduction: High-Intensity Interval Training (HIIT) and Constant-Intensity Endurance Training (CIET) improves peak oxygen uptake (V ̇O2) similarly in adults; but in children this remains unclear, as does the interaction with maturity. Methods: Thirty-seven boys formed three groups: HIIT (football; n = 14; 14.3 ± 3.1 years), CIET (distance runners; n = 12; 13.1 ± 2.5 years) and a control (CON) group (n = 11; 13.7 ± 3.2 years). Peak V ̇O2 and gas exchange threshold (GET) were determined from a ramp test with anaerobic performance quantified using a 30 m sprint pre-and-post a three-month training cycle. Maturation was assessed using maturity offset equations. Results: The HIIT groups peak V ̇O2 was significantly higher than the CON group pre (peak V ̇O2: 2.54±0.63 l•min -1 vs 2.03±0.53 l•min -1 , d = 0.88; GET: 1.41±0.26 l•min -1 vs 1.13±0.29 l•min -1 , d = 1.02) and post-training (peak V ̇O2: 2.63±0.73 l•min -1 vs 2.08±0.64 l•min -1 , d = 0.80; GET: 1.32±0.33 l•min -1 vs 1.15±0.38 l•min -1 , d = 0.48). All groups showed a similar magnitude of change over the three-month training period (p>0.05). HIIT was not superior to CIET for improving aerobic or anaerobic parameters in adolescents. Secondly, pre-and post-pubertal participants demonstrated similar trainability, highlighting no maturity and training interaction.
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Papers by Kelly Mackintosh