The Fitness and Health Study: The role of adiposity and cardiorespiratory fitness on health risk factors in overweight/obese children

Study Design: Parents and children presenting at Fiona Stanley Hospital identified as being overweight or obese will be provided with information related to the project. Thereafter, parents will then contact the researchers to express interest in their participation and they will be provided with the informed consent. In addition, parents and children will then come to Murdoch University for a site visit and a demonstration of the activities which will be completed. Further questions will be answered and informed consent (parent) and assent (child) obtained. Upon obtaining consent, participants will then be invited to attend the Exercise Physiology Clinic at Murdoch University for the collection of preliminary measurements and baseline data. Following baseline assessments, participants will then begin their 16-week exercise training intervention. Mid-intervention assessments will occur during Week 8 to assess aerobic fitness and strength. At least 24 hours after the last training session in Week 16, but no more than 96 hours after the last training session, participants will then complete their final assessment that is similar to the assessments at baseline. Procedures: Baseline testing will include body anthropometrics (height, weight, waist circumference and a dual energy X-ray absorptiometry [DXA] scan), aerobic fitness assessment (VO2 peak test performed on a cycle ergometer), a repetition max (RM) test for the bench press and leg press exercise, a 4-exercise functional movement screen (FMS), diet history (24h dietary recall conducted on 3 separate occasions representing different days), 7-day physical activity monitoring (Actigraph) and an appetite questionnaire. Additionally, participants will have their baseline blood sample taken at Fiona Stanley Hospital. Upon the completion of baseline assessments, participants will commence their first exercise training session of the intervention. Over the subsequent 16 weeks, participants will be trained (two times per week; 40-60 minutes) using a mix of aerobic, resistance and movement skills (coordination) program. These will be individualised and progressively increased over the weeks with the aim of improving the different facets of fitness (e.g. aerobic fitness and strength). The aerobic exercise portion of the training program will be completed at approximately ~60-70% of VO2 peak for 20 minutes. The intensity of the exercises will be tailored/progressed based on the participant’s performance in the VO2peak test completed at baseline and at mid-intervention (Week 8). The resistance exercises will be conducted in a circuit fashion that incorporates exercises involving both the upper and lower body (e.g. leg press, goblet squats, push ups and lat pulldown exercises) for an approximate duration of 20 minutes. Progression in the intensity of resistance exercises will utilise a 2x2 rule (i.e. intensity is increased if an individual is able to successfully complete 2 or more repetitions in the last set on 2 consecutive workouts). Lastly, the movement skills portion of the training will incorporate different sports (e.g. basketball, soccer, tennis and etc.) for approximately 20mins with the aim of maintaining average heart rate during this period between 60-70% of heart rate max. During the sessions, we will also be encouraging increased physical activity (monitored with the activity tracker) and improved sleep habits (earlier bed-times where appropriate; currently, children in the program have demonstrated poor sleep behaviours such as going to bed between 1-3am on weekdays). The training workload (volume and intensity) will be monitored closely by the exercise physiologist at every session. All exercise sessions will be recorded in a logbook with attendance taken as well as sessional RPE for each individual training session over the 16-week period. At the completion of the intervention, post-intervention assessments will be completed in one session at Murdoch University with the assessments being similar to those at baseline. This test will occur at least 24h after, but not more than 72h, the last exercise training session.