The influence of a six-week, high-intensity games intervention on the pulmonary oxygen uptake kinetics in prepubertal obese and normal-weight children

Background: The pulmonary oxygen uptake ( O2) response is deleteriously influenced by obesity in pre-pubertal children, as evidenced by a slower phase II response. To date, no studies have investigated the ability of an exercise intervention to ameliorate this. Objectives: To investigate the influence of a six week, high-intensity games orientated intervention on the O2 kinetic response of pre-pubertal obese (OB) and normal-weight (NW) children during heavy intensity exercise. Methods: Thirteen NW and fifteen OB children participated in a twice-weekly exercise intervention involving repeated bouts of 6-minutes of high-intensity, games-orientated exercises followed by 2 minutes of recovery. Sixteen NW and 11 OB children served as a control group. At baseline and post-intervention, each participant completed a graded-exercise test to volitional exhaustion and constant work rate heavy intensity exercise.Results: Post intervention, OB children demonstrated a reduced phase II τ (Pre: 30±8 cf. Post: 24±7 s), MRT (Pre: 50±10 cf. Post: 38±9 s) and phase II amplitude (Pre: 1.51±0.30 cf. Post: 1.34±0.27 l∙min-1). No changes were evident in the NW children. Conclusions: The present findings demonstrate that a six-week, high-intensity intervention can have a significant positive impact on the dynamic O2 response of obese pre-pubertal children

The influence of body weight on the pulmonary oxygen uptake kinetics in pre-pubertal children during moderate- and heavy intensity treadmill exercise

To assess the influence of obesity on the oxygen uptake (V˙O2) kinetics of pre-pubertal children during moderate- and heavy intensity treadmill exercise. We hypothesised that obese (OB) children would demonstrate significantly slower V˙O2 kinetics than their normal weight (NW) counterparts during moderate- and heavy intensity exercise. 18 OB (9.8 ± 0.5 years; 24.1 ± 2.0 kg m2) and 19 NW (9.7 ± 0.5 years; 17.6 ± 1.0 kg m2) children completed a graded-exercise test to volitional exhaustion and two submaximal constant work rate treadmill tests at moderate (90 % gas exchange threshold) and heavy (∆40 %) exercise intensities. Bodyweight significantly influenced the V˙O2 kinetics during both moderate- and heavy exercise intensities (P < 0.05). During moderate intensity exercise, the phase II τ (OB: 30 ± 13 cf. NW: 22 ± 7 s), mean response time (MRT; OB: 35 ± 16 cf. NW: 25 ± 10 s), phase II gain (OB: 156 ± 21 cf. NW: 111 ± 18 mLO2 kg−1 km−1) and oxygen deficit (OB: 0.36 ± 0.11 cf. NW: 0.20 ± 0.06 L) were significantly higher in the OB children (all P < 0.05). During heavy intensity exercise, the τ (OB: 33 ± 9 cf. NW: 27 ± 6 s; P < 0.05) and phase II gain (OB: 212 ± 61 cf. NW: 163 ± 23 mLO2 kg−1 km−1; P < 0.05) were similarly higher in the OB children. A slow component was observed in all participants during heavy intensity exercise, but was not influenced by weight status. In conclusion, this study demonstrates that weight status significantly influences the dynamic V˙O2 response at the onset of treadmill exercise in children and highlights that the deleterious effects of being obese are already manifest pre-puberty

The effect of a child-specific high intensity games intervention on physiological responses in normal weight and obese children : submitted by Nicole Westrupp to Massey University Wellington as a thesis towards the degree of Master of Health Science with Sport and Exercise Science (February, 2013)

To date, little is known about the use of child- specific high-intensity games- based exercise to improve body composition, cardiovascular indices, musculoskeletal health, psychological and social well-being. Past research in children has predominantly focused on the effect of laboratory or games based moderate intensity exercise interventions on the aforementioned markers of health (Janssen & LeBlanc, 2010). Therefore, the aim of this investigation is to assess the effect of a 6 week high-intensity games-based intervention on the physiological responses and physical parameters in normal and overweight or obese children aged 8 to 10 years. Twenty eight children were randomized into an exercise group (EX; 9.3 ± 0.9 y, 1.40 ± 0.10 m, 41.0 ± 12.4 kg, 20.5 ± 4.4 kg·m2) and 27 children into a control group (CON; 9.3 ± 0.8 y, 1.40 ± 0.09 m, 39.0 ± 11.3 kg, 19.5 ± 4.1 kg·m2). All participants completed two, pre-intervention (pre-INT) exercise tests on a treadmill i) discontinuous graded exercise test (GXT) to peak oxygen consumption (O2peak) and ii) a submaximal exercise test at running speeds equivalent to moderate (ventilatory threshold [VT]) and heavy (40% delta [difference between O2peak and VT]) intensity exercise for a total of 6 minutes. The EX group took part in 2 x 40 minute high-intensity child-specific games-based exercise sessions per week for 6 weeks. Follow-up assessments identical to the pre-INT were completed thereafter for all participants. The EX group from pre to post intervention (post-INT) demonstrated a significant increase in absolute O2peak and running speed for the GXT test (P < .05); and demonstrated a significant increase in their running speed at VT (7.8 ± 0.9 vs. 8.2 ± 0.8 km·h-1) and 40% delta (9.4 ± 1.0 vs. 9.9 ± 1.1 km·h-1; P < .05) when compared to the CON group. A significant decrease in O2 at VT and 40% delta was also observed for the EX group in comparison to the CON group (P < .05), thus demonstrating an improvement in exercise efficiency. In conclusion, a short duration (6 week) child-specific high intensity games intervention may improve maximal functional capacity and exercise efficiency, independent of body mass in children aged 8 to 10 years. An increase in the oxygen carrying capacity of blood, and capillary and mitochondrial density within the skeletal muscle are potential mechanisms for the aforementioned outcomes. Findings from this study provide important information concerning the practical application of physical activity within school or clinical-based programmes to improve health and physical fitness

The influence of a six week exercise intervention on the pulmonary oxygen uptake kinetics in 1 pre-pubertal obese and normal weight children 2 3

Abstract 23 Purpose: The pulmonary oxygen uptake (V O 2 ) response is deleteriously influenced by obesity in pre-24 pubertal children, as evidenced by a slower phase II response relative to their normal-weight 25 counterparts. To date, no studies have investigated the ability of an exercise intervention to ameliorate 26 this deleterious influence. Therefore, the purpose of the present study was to investigate the influence 27 of a six week, high-intensity games orientated intervention on the O 2 kinetic response of pre-28 pubertal obese (OB) and normal-weight (NW) children during heavy intensity exercise. 29 Methods: Thirteen NW and fifteen OB children participated in a twice weekly exercise intervention 30 involving repeated bouts of 6-minutes of high-intensity, games-orientated exercises followed by 2 31 minutes of recovery. Sixteen NW and eleven OB children served as a control group. At baseline and 32 post-intervention, each participant completed a graded-exercise test to volitional exhaustion and 33 constant work rate heavy intensity exercise (40% of the difference between the gas exchange 34 threshold and peak V O 2 )

Sexual differences in central arterial wave reflection are evident in prepubescent children

OBJECTIVE: The objective of this study was to examine the influence of sex on central arterial wave reflection in healthy prepubescent children matched for body size and cardiorespiratory fitness.METHODS: Fifty-five healthy children (9.8?±?1.0 years, 44% girls) were recruited. Cardiorespiratory fitness was assessed using a treadmill-based graded exercise test to volitional exhaustion. Pulse wave analysis was used to measure augmentation index (AIx) and central blood pressures.RESULTS: The girls and boys were matched for age, body size and cardiorespiratory fitness. There were no significant differences between sexes for heart rate or central blood pressure parameters. Girls demonstrated a significantly greater AIx than the boys (8.9?±?9.3 vs. 1.9?±?10.8%, P?=?0.015, d?=?0.69).CONCLUSION: Sexual differences in central arterial wave reflection exist prepubescence, independent of stature or cardiorespiratory fitness. Further study is required to elucidate the mechanism(s) explaining this phenomenon and to determine the influence of wave reflections on left ventricular mass during childhood

The effectiveness of a high-intensity games intervention on improving indices of health in young children

This study assessed the effectiveness of a 6-week, high-intensity, games-based intervention on physiological and anthropometric indices of health, in normal weight (n = 26; 32.5 ± 8.9 kg) and obese (n = 29; 49.3 ± 8.9 kg) children (n = 32 boys, 23 girls), aged 8–10 years. Children were randomised into an exercise or control group. The exercise group participated in a twice-weekly, 40 min active games intervention, alongside their usual school physical education classes. The control group did not take part in the intervention. Before and after the intervention, participants completed both a maximal and submaximal graded exercise test. The submaximal exercise test comprised of a 6 min, moderate- and 6 min heavy-intensity bout, interspersed with a 5 min recovery. The exercise group demonstrated improvements in maximal oxygen uptake (51.4 ± 8.5 vs 54.3 ± 9.6 ml · kg?1 · min?1) and peak running speed (11.3 ± 1.6 vs 11.9 ± 1.6 km · h?1), and a reduction in the oxygen cost of submaximal exercise between assessments (P &lt; .05). A decrease in waist circumference and increase in muscle mass were observed between assessments for the obese participants randomised to the intervention (both P &lt; .05). This study demonstrates that a short-term, high-intensity games intervention may elicit positive changes in physiological and anthropometric indices of health in normal weight and obese children