The 4T Exercise Study started newly diagnosed youth with T1D on CGM and physical activity (PA) trackers ~1-month post diagnosis. We examined real-world PA patterns and glycemia in youth with T1D during the first year post diagnosis. A physically active day was identified as ≥10 mins of continuous moderate-to-vigorous intensity PA, with moderate-intensity (MOD) defined as 3-6 metabolic equivalents (METS) and high-intensity (HIE) as >6 METS. All other days were deemed as sedentary (SED) days. CGM data 24h after exercise were used to compute percent time below range (TBR; <70 and TBR2; <54 mg/dL), time in range (TIR; 70-180 mg/dL), and time above range (TAR; >180 and TAR2; >250 mg/dL). A total of 45 youth (age: 13 [IQR 12, 15] years, 38% female, 40% non-Hispanic White, 76% private insurance) wore activity trackers 13 [IQR: 8, 16] hours daily. Compared to SED days, higher intensity PA levels were associated with higher TIR (70% SED vs 72% with MOD, P=0.2; 76% with HIE, P=0.001) and lower TAR (28% SED vs 24% with MOD, P=0.08; 21% with HIE, P<0.001), but no difference in TBR (2.8% SED vs 3.6% following MOD, P=0.2; 3.7% following HIE, P=0.14). Overall, higher levels of PA in youth with new onset T1D was associated with over an hour of increased TIR per day, without significant increases in TBR. Exercise education soon after diagnosis is an opportunity to improve care and establish safe and healthy PA habits.


D.P.Zaharieva: Advisory Panel; Dexcom, Inc., Research Support; Hemsley Charitable Trust, International Society for Pediatric and Adolescent Diabetes, Insulet Corporation, Speaker's Bureau; American Diabetes Association, Ascensia Diabetes Care, Medtronic. D.M.Maahs: Advisory Panel; Medtronic, LifeScan Diabetes Institute, MannKind Corporation, Consultant; Abbott, Research Support; Dexcom, Inc. V.Ritter: None. M.Riddell: Advisory Panel; Zealand Pharma A/S, Zucara Therapeutics, Indigo Diabetes, Consultant; Lilly Diabetes, Eli Lilly and Company, Jaeb Center for Health Research, Speaker's Bureau; Dexcom, Inc., Novo Nordisk, Sanofi, Stock/Shareholder; Supersapiens, Zucara Therapeutics. A.Addala: None. F.K.Bishop: None. P.Prahalad: None. M.Desai: None. K.K.Hood: Consultant; Cecelia Health. D.Scheinker: None.


National Institutes of Health (P30DK116074); Stanford Diabetes Research Center (R18DK122422 to D.M.M.); Dexcom, Inc.; Lucile Packard Children’s Hospital Auxiliaries Endowment; The Leona M. and Harry B. Helmsley Charitable Trust (G-2002-0425); Internationa

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