On-field physical activity of Special Olympics athletes and Unified Partners during the 2022 Special Olympics World Unified Cup

BACKGROUND

Special Olympics is a sport organisation spearheading efforts to increase physical activity accessibility through inclusive sport. The Unified Sports® initiative brings together Special Olympics athletes (with intellectual disabilities) and Unified partners (without a disability) in sport training and competition on the same team. The study aims to objectively evaluate differences in on-field physical activity levels between athletes and partners during the 2022 Special Olympics World Unified Cup, an international soccer (i.e., football) competition. Participants were Special Olympics athletes (n = 96; 44 females, 52 males) and Unified partners (n = 70; 34 females and 36 males) competing in the women's and men's tournaments.

METHODS

On-field actigraph accelerometry measured physical activity from 166 players, over 29 matches, and totalling 493 player-matches.

RESULTS

In the women's tournament, nearly identical estimates of moderate-to-vigorous physical activity levels (MVPA) were observed between athletes and partners (P = .409). However, a significant group difference was observed within a specific physical activity intensity category as partners accrued more minutes of very vigorous physical activity than athletes (P < .001). In the men's tournament, no significant differences were also observed between athletes and partners for minutes of MVPA (P = .341), but athletes engaged in significantly more vigorous physical activity (P < .001), and partners had more minutes of very vigorous physical activity (P < .001).

CONCLUSIONS

The results suggest that on-field physical activity levels were similar between players with and without intellectual disabilities during Unified Sports competition.

Predicting the rate of oxygen uptake from step counts using ActiGraph waist-worn accelerometers in adults with Down syndrome

BACKGROUND

Step rate predicts ambulatory intensity as reflected in the rate of oxygen uptake (VO₂ ) - a measure of energy expenditure. Whether step rate as measured by an accelerometer predicts VO₂ in adults with Down syndrome (DS) is unknown. We examined whether step rate predicts VO₂ in adults with and without DS. We also developed an equation for predicting VO₂ and examined its accuracy.

METHOD

Sixteen adults with DS (6 women and 10 men; age 31 ± 15 years) and 19 adults without DS (9 women and 10 men; age 25 ± 6 years) performed standing and walking at their preferred speed, 0.8 and 1.4 m·s^-1 . We measured VO₂ with a portable spirometer and step rate with a triaxial accelerometer (wGT3X-BT; ActiGraph) on the non-dominant hip, using the low-frequency extension filter. We ran multilevel regression for predicting VO₂ from linear and quadratic terms for step rate, group (1 = DS; 0 = non-DS), body mass, height, body mass index (BMI), leg length and sex. We estimated VO₂ with the resultant equation and calculated the equation's absolute per cent error, which we compared between groups.

RESULTS

VO₂ was higher in persons with than without DS only at the fast walking speed (P = 0.018). DS did not predict VO₂ . Step rate, step rate squared and BMI were significant predictors of VO₂ (P < 0.001; R²  = 0.80). Absolute error across walking speeds was 13.5-18.8% and 11.7-13.4% for adults with and without DS, respectively, and did not differ between groups or speeds.

CONCLUSIONS

Step rate, step rate squared and BMI predict VO₂ in adults with and without DS. Prediction error does not differ between groups.

Diurnal cortisol and obesity in adolescents with and without Down syndrome

BACKGROUND

The prevalence of obesity in adolescents with Down syndrome (DS) far exceeds that in the general population. Cortisol, an adrenal hormone, can be obesogenic when dysregulated. However, the diurnal patterns of this hormone have not been examined among individuals with DS. Variations in adiposity may also mediate cortisol regulation. This study sought to examine diurnal cortisol patterns in adolescents with DS as well as associations between cortisol function and obesity.

METHOD

A total of 32 adolescents, including 16 with DS and 16 controls with typical development (TD) of similar sex, age and Tanner pubertal stage (P > 0.05), participated in this preliminary study. Participants completed a dual-energy X-ray absorptiometry scan to measure body composition and collected saliva samples for cortisol measurements in the morning, afternoon and night. Linear mixed models with random intercepts and repeated measures were used to examine the daily trajectory of log-transformed cortisol concentrations between adolescents with and without DS. A second model examined the interaction between DS and presence of elevated body fatness.

RESULTS

Adolescents with DS had higher morning cortisol concentrations (intercept = 0.37 μg/dL), but this was not significantly different than in TD (0.35 μg/dL, P = 0.16). Cortisol significantly declined across hours (b = -0.026 μg/dL/h, P < 0.001), but this decline also did not differ from that observed in TD (b = -0.024 μg/dL/h, P = 0.43). While cortisol levels were slightly higher among adolescents with elevated body fatness, this difference was not statistically significant (P > 0.05; d = 0.30).

CONCLUSIONS

This study is the first to examine diurnal cortisol in DS but is limited in sample size. These preliminary findings suggest that diurnal cortisol patterns are not significantly different between adolescents with DS and TD and that cortisol levels are not associated with adiposity in this population. Despite these non-significant differences, youth with DS continue to be an 'at-risk' population for paediatric obesity in need of clinical intervention.