ABSTRACT
BACKGROUND: Lockdown restrictions reduce COVID-19 community transmission; however, they may pose challenges for noncommunicable disease management. A 112-day hard lockdown in Victoria, Australia (commencing March 23, 2020) coincided with an intervention trial of reducing and breaking up sitting time in desk workers with type 2 diabetes who were using a provided consumer-grade activity tracker (Fitbit). OBJECTIVE: This study aims to compare continuously recorded activity levels preceding and during COVID-19 lockdown restrictions among working adults with type 2 diabetes participating in a sitting less and moving more intervention. METHODS: A total of 11 participants (n=8 male; mean age 52.8, SD 5 years) in Melbourne, Australia had Fitbit activity tracked before (mean 122.7, SD 47.9 days) and during (mean 99.7, SD 62.5 days) citywide COVID-19 lockdown restrictions. Regression models compared device (Fitbit Inspire HR)-derived activity (steps; metabolic equivalent tasks [METs]; mean time in sedentary, lightly, fairly, and very active minutes; and usual bout durations) during restrictions to prerestrictions. Changes in activity were statistically significant when estimates (Δ%) did not intercept zero. RESULTS: Overall, there was a decrease in mean steps (-1584 steps/day; Δ% -9%, 95% CI -11% to -7%); METs (-83 METs/day; Δ% -5%, 95% CI -6% to -5%); and lightly active (Δ% -4%, 95% CI -8% to -1%), fairly active (Δ% -8%, 95% CI -21% to -15%), and very active (Δ% -8%, 95% CI -11% to -5%) intensity minutes per day, and increases in mean sedentary minutes per day (51 mins/day; Δ% 3%, 95% CI 1%-6%). Only very active (+5.1 mins) and sedentary (+4.3 mins) bout durations changed significantly. CONCLUSIONS: In a convenience sample of adults with type 2 diabetes, COVID-19 lockdown restrictions were associated with decreases in overall activity levels and increases in very active and sedentary bout durations. A Fitbit monitor provided meaningful continuous long-term data in this context. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12618001159246; https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12618001159246.
ABSTRACT
PURPOSE: In healthy adults, the impairment of vascular function associated with prolonged sitting can be mitigated with intermittent brief bouts of activity. It is unknown whether these benefits extend to women with polycystic ovary syndrome (PCOS), in whom vascular function is typically impaired and sitting time is high. We examined the acute effect of regularly interrupting sitting time with brief simple resistance activities (SRA) on vascular function in PCOS. METHODS: In a randomized crossover trial, 13 physically inactive women with PCOS (18-45 yr) completed two 3.5-h conditions: 1) uninterrupted sitting (SIT) and 2) sitting interrupted by 3-min bouts of SRA every 30 min. Femoral artery flow-mediated dilation (FMD), resting shear rate, and resting blood flow were measured at 0, 1, and 3.5 h. RESULTS: Mean resting femoral shear rate, averaged across the 3.5 h, significantly increased in the SRA condition relative to the SIT condition (40.1 ± 6.1 vs 62.8 ± 6.1 s-1, P < 0.0001). In addition, mean resting blood flow also significantly increased across the 3.5 h for SRA relative to SIT (45.0 ± 9.8 vs 72.8 ± 9.9 mL·min-1, P < 0.0001). There were no differences between conditions in the temporal change in femoral artery FMD across 3.5 h (Ptime-condition > 0.05 for all). CONCLUSION: Frequently interrupting sitting with SRA acutely increased resting shear rate and blood flow in women with PCOS but did not alter FMD. With sedentary behavior increasing in prevalence, longer-term studies of similar interventions to reduce and break up sitting time are warranted.
