Perceptions of a family-based lifestyle intervention for children with overweight and obesity: a qualitative study on sustainability, self-regulation, and program optimization.

BACKGROUND: Family-based lifestyle interventions (FBLIs) are an important method for treating childhood weight problems. Despite being recognized as an effective intervention method, the optimal structure of these interventions for children's overweight and obesity has yet to be determined. Our aim was to better understand participants' (a) implementation of behaviour strategies and long-term outcomes, (b) perceptions regarding the optimal structure of FBLIs, and (c) insights into psychological concepts that may explain the success of these programs. METHODS: Purposive sampling was used to recruit participants. We conducted focus groups as well as one-to-one interviews with parents (n = 53) and children (n = 50; aged 7-13, M = 9.4 yr, SD = 3.1) three months following their involvement in a 10-week, multi-component, FBLI involving education and activities relating to healthy nutrition, physical activity, and behavior modification. Using an interpretivist approach, a qualitative study design was employed to examine participant experiences. RESULTS: We identified three higher-order categories: (a) participants' program experiences and perceptions (b) lifestyle changes post-program, and (c) recommendations for optimizing family-based programs. Themes identified within these categories included (a) support and structure & content, (b) diet and physical activity, and (c) in-program recommendations and post-program recommendations. CONCLUSIONS: We identified several challenges that can impair lasting behavior change (e.g., physical activity participation) following involvement in a FBLI. On optimizing these programs, participants emphasized fun, interactive content, interpersonal support, appropriate educational content, and behavior change techniques. Concepts rooted in motivational theory could help address calls for greater theoretical and mechanistic insight in FBLIs. Findings may support research advancement and assist health professionals to more consistently realize the potential of these interventions.

Acute hyperglycaemia does not have a consistent adverse effect on exercise performance in recreationally active young people with type 1 diabetes: a randomised crossover in-clinic study.

AIMS/HYPOTHESIS: In individuals with type 1 diabetes, chronic hyperglycaemia impairs aerobic fitness. However, the effect of acute marked hyperglycaemia on aerobic fitness is unclear, and the impact of insulin level has not been examined. In this study, we explored if acute hyperglycaemia with higher or low insulin levels affects [Formula: see text] and other exercise performance indicators in individuals with type 1 diabetes. METHODS: Eligible participants were aged 14 to 30 years, with complication-free, type 1 diabetes and HbA1c ≤ 75 mmol/mol (≤9%). Participants exercised in a clinical laboratory under three clamp (constant insulin, variable glucose infusion) conditions: euglycaemia (5 mmol/l) with 20 mU [m2 BSA]-1 min-1 insulin (where BSA is body surface area) (Eu20); hyperglycaemia (17 mmol/l) with 20 mU [m2 BSA]-1 min-1 insulin (Hyper20); and hyperglycaemia (17 mmol/l) with 5 mU [m2 BSA]-1 min-1 insulin (Hyper5) on separate days. Participants and the single testing assessor were blinded to condition, with participants allocated to randomised testing condition sequences as they were consecutively recruited. Standardised testing (in order) conducted on each of the three study days included: triplicate 6 second sprint cycling, grip strength, single leg static balance, vertical jump and modified Star Excursion Balance Test, ten simple and choice reaction times and one cycle ergometer [Formula: see text] test. The difference between conditions in the aforementioned testing measures was analysed, with the primary outcome being the difference in [Formula: see text]. RESULTS: Twelve recreationally active individuals with type 1 diabetes (8 male, mean ± SD 17.9 ± 3.9 years, HbA1c 61 ± 11 mmol/mol [7.7 ± 1.0%], 7 ± 3 h exercise/week) were analysed. Compared with Eu20, [Formula: see text] was lower in Hyper20 (difference 0.17 l/min [95% CI 0.31, 0.04; p = 0.02] 6.6% of mean Eu20 level), but Hyper5 was not different (p = 0.39). Compared with Eu20, sprint cycling peak power was not different in Hyper20 (p = 0.20), but was higher in Hyper5 (64 W [95% CI 13, 115; p = 0.02] 13.1%). Hyper20 reaction times were not different (simple: p = 0.12) but Hyper5 reaction times were slower (simple: 11 milliseconds [95% CI 1, 22; p = 0.04] 4.7%) than Eu20. No differences between Eu20 and either hyperglycaemic condition were observed for the other testing measures (p > 0.05). CONCLUSIONS/INTERPRETATION: Acute marked hyperglycaemia in the higher but not low insulin state impaired [Formula: see text] but to a small extent. Acute hyperglycaemia had an insulin-dependent effect on sprint cycling absolute power output and reaction time but with differing directionality (positive for sprint cycling and negative for reaction time) and no effect on the other indicators of exercise performance examined. We find that acute hyperglycaemia is not consistently adverse and does not impair overall exercise performance to an extent clinically relevant for recreationally active individuals with type 1 diabetes. FUNDING: This research was funded by Diabetes Research Western Australia and Australasian Paediatric Endocrine Group grants.

Comparison of Linear and Reverse Linear Periodized Programs With Equated Volume and Intensity for Endurance Running Performance.

Bradbury, DG, Landers, GJ, Benjanuvatra, N, and Goods, PS. Comparison of linear and reverse linear periodized programs with equated volume and intensity for endurance running performance. J Strength Cond Res 34(5): 1345-1353, 2020-This investigation examined the effectiveness of 2 periodization methods on endurance running performance. Thirty recreational runners (25.2 ± 7.4 years; 175.4 ± 8.1 cm; 69.0 ± 9.8 kg) were assigned to 3 groups based on preintervention test results: linear periodization group (LPG, n = 10), reverse linear periodization group (RPG, n = 10), and control group (CG, n = 10). The LPG and RPG completed 3 training sessions (2 supervised and 1 unsupervised) per week in two 6-week blocks. The LPG went through a high-volume training program while the RPG performed higher intensity, lower volume training in the initial block. Training volume and intensity was reversed in the second 6-week training block. All subjects completed pre-training (week 0), midpoint (week 7), and post-training (week 14) testing, which included anthropometric measurements (body mass and sum of 8 skinfolds), treadmill tests for running economy (RE) and V[Combining Dot Above]O2max, and a 5,000-m time trial (TT) on a 400-m grass track. Greater improvements in the 5,000-m TT were observed in the LPG (76.8 ± 55.8 seconds, p = 0.009, d = 1.27) and the RPG (112.8 ± 83.4 seconds, p = 0.002, d = 1.51) than the CG (3.6 ± 59 seconds). No significant differences were found between the LPG and RPG (p = 0.321, d = 0.51). No group differences were found for V[Combining Dot Above]O2peak (p = 0.955) or RE at 9 km·h (p = 0.329) or 11 km·h (p = 0.558), respectively. However, significant improvements were seen in these variables after training: V[Combining Dot Above]O2peak (p = 0.010), RE 9 km·h (p < 0.001), and RE 11 km·h (p = 0.004). These results do not support linear periodization or reverse linear periodization as a superior method; however, periodized training elicited greater improvements in endurance performance than nonperiodized training, highlighting the importance of planned training structure.

Comparison of ground reaction force asymmetry in one- and two-legged countermovement jumps.

This study examined whether ground reaction force (GRF) asymmetry of 2-legged countermovement jumps (CMJ) is related to 1-legged CMJ asymmetry. The GRF asymmetry of a 2-legged CMJ has been suggested as a preferred test to the 1-legged CMJ for functional strength and power deficit assessment. Twenty-eight men and 30 women performed 5 trials each of a 1-legged CMJ with the right limband the left limb, and a 2-legged CMJ. Vertical GRFs were collected from each lower limb using 2 force platforms. Although several GRF variables were calculated, vertical impulse correlated most strongly with jump height in all conditions (p < 0.05), and they were used in subsequent analyses. A moderate correlation was found for impulse asymmetry between the 1- and 2-legged CMJs for women (r = 0.45, p < 0.05), but not for men (r = 0.06, p = 0.76). In contrast, cross-tabulation analyses of subjects presented with the same dominant characteristics in the 1- and 2-legged CMJs revealed poor associations for both men (Freeman-Halton exact p = 0.61) and women (Freeman-Halton exact p = 0.19). Only 11 women recorded the same dominant limb for both 1- and 2-legged CMJs. This suggests that impulse asymmetries found in the 1- and 2-legged CMJ were unrelated. As the 1-legged CMJ relies on the extension forces generated entirely from 1 limb, variations in jump heights and GRF impulses by left and right limbs separately were more indicative of functional strength differences between sides. Hence, it is recommended that the 1-legged CMJ is used when examining functional strength asymmetry in the lower limbs. In contrast, factors causing asymmetry in GRF impulses during 2-legged CMJs are more complicated and require further investigation.

Body Segment Inertial Parameters of elite swimmers Using DXA and indirect Methods.

As accurate body segment inertial parameters (BSIPs) are difficult to obtain in motion analysis, this study computed individual BSIPs from DXA scan images. Therefore, by co-registering areal density data with DXA grayscale image, the relationship between pixel color gradient and the mass within the pixel area could be established. Thus, one can calculate BSIPs, including segment mass, center of mass (COM) and moment of inertia about the sagittal axis (Ixx). This technique calculated whole body mass very accurately (%RMSE of < 1.5%) relatively to results of the generic DXA scanner software. The BSIPs of elite male and female swimmers, and young adult Caucasian males (n = 28), were computed using this DXA method and 5 other common indirect estimation methods. A 3D surface scan of each subject enabled mapping of key anthropometric variables required for the 5 indirect estimation methods. Mass, COM and Ixx were calculated for seven body segments (head, trunk, head + trunk, upper arm, forearm, thigh and shank). Between-group comparisons of BSIPs revealed that elite female swimmers had the lowest segment masses of the three groups (p < 0.05). Elite male swimmers recorded the greatest inertial parameters of the trunk and upper arms (p < 0.05). Using the DXA method as the criterion, the five indirect methods produced errors greater than 10% for at least one BSIP in all three populations. Therefore, caution is required when computing BSIPs for elite swimmers via these indirect methods, DXA accurately estimated BSIPs in the frontal plane. Key PointsElite swimmers have significantly different body segment inertial parameters than young adult Caucasian males.The errors computed from indirect BSIP estimation methods are large regardless whether applied to elite swimmers or young adult Caucasian males.No indirect estimation method consistently performed best.

Deep Brain Stimulation and Swimming Performance: A Randomized Within-Person Crossover Study.

OBJECTIVE: To determine whether deep brain stimulation (DBS) causes swimming impairment, we systematically compared swimming ability between DBS on vs off in 18 patients. METHODS: We conducted a randomized blinded crossover study, comparing swimming ability between DBS on vs off, within participants. Participants swam 3 laps of front crawl and 3 laps of breaststroke. Prespecifed primary outcomes were proportion of lap completed, lap time, and Aquatic Skills Proficiency Assessment (ASPA) score. Prespecified secondary outcomes were a qualitative description of marked changes observed. RESULTS: Eighteen participants with Parkinson disease (n = 13), essential tremor (n = 3), Tourette syndrome (n = 1), or posttraumatic brain injury proximal tremor (n = 1), treated with posterior subthalamic area (n = 15) or globus pallidus interna (n = 3) DBS were assessed. There was no significant effect of DBS on/off status on any outcome measure for front crawl or breaststroke. Three participants showed changes in both qualitative and quantitative assessments. Of these, 1 participant displayed reduction in swimming ability: impairment in all outcomes with DBS on, normalizing with DBS off (the same individual as previously reported). The participant displayed difficulty coordinating limb movement as well as postural control. Two participants showed improvements in lap time and ASPA scores with DBS on. CONCLUSION: Overall DBS did not impair swimming performance, although 1 patient demonstrated a stimulation-induced drowning hazard. There were no anatomic or clinical features unique to the individual with swimming impairment. Patients should be warned about the possibility of DBS-induced drowning hazard and should swim with capable supervision after DBS. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with implanted DBS electrodes, the stimulation on condition, compared with stimulation off, did not significantly impair swimming performance. A formal assessment of unblinding would have been helpful.

The Effects of Water-based Exercise Training in People with Type 2 Diabetes.

PURPOSE: To investigate the effects of 8 wk of upright water-based exercise training in people with type 2 diabetes. METHODS: Thirteen participants with type 2 diabetes (54% male; 60.9 ± 9.6 yr, mean ± standard deviation) completed 8 wk of upright water-based exercise training at a moderate intensity (60%-80% of exercise test-derived maximum HR), for 1 h, three times a week (TG). Fourteen participants (64% male; 63.9 ± 9.8 yr) acted as a control group (CG) who maintained their usual activities. Preintervention and postintervention, participants performed cardiopulmonary exercise testing to determine V˙O2peak and one-repetition maximum testing to assess muscular strength. Blood profiles were assessed with standard assays. Body mass index and waist/hip ratio were employed as measures of anthropometry. Endothelium-dependent (brachial artery flow-mediated dilation) and independent (glyceryl trinitrate-mediated) function were assessed using vascular ultrasound. RESULTS: Water-based training increased V˙O2peak (18.5 ± 4.3 mL·kg·min to 21.5 ± 5.4 mL·kg·min) (P = 0.002), overall muscle strength (123 ± 44 kg to 139 ± 43 kg) and leg strength (92 ± 28 kg to 104 ± 29 kg), compared with the CG (P = 0.001). The effect on pectoral strength (31 ± 17 kg to 35 ± 16 kg) was not significantly different to the CG (24 ± 12 kg to 26 ± 14 kg) (P = 0.08). No change was observed in anthropometry, blood profiles, or glyceryl trinitrate-mediated vascular function. Flow-mediated dilation was increased after training (6.1% ± 2.4% to 6.5% ± 3.0%), compared with controls who demonstrated a slight decrease (6.2% ± 1.6% to 5.4% ± 1.6%) (P = 0.002). CONCLUSIONS: Water-based circuit training was well tolerated and appears to be an effective exercise modality for improving aerobic fitness, strength, and vascular function in people with type 2 diabetes.

Do footedness and strength asymmetry relate to the dominant stance in swimming track start?

This study explored the relationship between lower limb asymmetry and stance preference in the swimming track start. Track start performances and asymmetry measures were collected from 11 male and 11 female competitive age group swimmers. The track start performance was defined as the time taken to reach the 5-m mark. Asymmetry measures included assessment of footedness using the revised version of the Waterloo Footedness Questionnaire and assessment of performance asymmetry in the one-legged countermovement jump. Participants performed five trials on each side of both the one-legged countermovement jump and the track start, and the best three trials of each were compared. Asymmetry was declared when at least two trials from one side were better than the contralateral side. While the majority of the participants produced better performances using the preferred track start stance, it was not related to footedness or the dominant limb for the one-legged countermovement jump. Further investigation is required to identify factors that predict the lateralised behaviour of the track start, and determine whether changing the stance would provide significant advantage.