Participants In total, we included 6270 CHMS participants in analyses (rounded to the nearest 10 as per StatisticsCanadaconfidentialityrequirements). Cross sectionalweightedanalysesindicatedthat23.9%, 4.9%, and 0.5% had one, two, and three or more CDs, respectively. Participants with multimorbidity averaged 9.7 (SE = 0.9) (2 CDs) and 6.4 (SE = 1) (≥3 CDs) minutes per day in MVPA and 171.4 (SE = 7) (2 CDs) and 155.4 (SE = 9.6) (≥3 CDs) minutes per day in LPA, and accumulated an average of 5779 (SE = 303.5) (2 CDs) and 5483 (SE = 666.9) (≥3 CDs) steps per day. Multimorbid participants spent an average of 579.7 (SE = 6.4) (2 CDs) and 606.8 (SE = 16.1) (≥3 CDs) minutes per day in sedentary behaviors. Detailed participant characteristics are shown in Table 1 and in the Supplementary file. Descriptive data about physical activity outcomes and sedentary behavior among participants with heart disease, diabetes, cancer or COPD are also provided in the Supplementary file [38]. Multimorbid participants had significantly lower daily MVPA (2 CDs [p = 0.02×10−4, d =−0.12]; ≥3 CDs [p = 0.07 × 10−5, d = −0.28]), LPA duration (2 CDs [p = 0.05 × 10−1, d = −0.07]; ≥3 CDs [p = 0.04×10−3, d =−0.24]) and daily number of steps (2 CDs [p = 0.02×10−2, d =−0.10];≥3 CDs [p = 0.01×10−1, d =−0.17]) compared to adults without CDs. Daily time spent in sedentary behaviors was significantly higher in multimorbid participants (2 CDs [p = 0.08 × 10−1, d = −0.07]; ≥3 CDs [p = 0.02×10−1, d =−0.17]) (Figure 1). No significant differences in MVPA, LPA, or number of steps per day were found between adults with a single CD compared to those with no CDs. Details about statistical findings are available in the Supplementary file. Sports 2019,