An observational study presented at the American College of Cardiology’s Annual Scientific Session (ACC.26) and not yet published in a peer-reviewed journal suggests that exercising in the morning is associated with lower rates of cardiometabolic conditions compared with later-day exercise. Researchers analyzed minute-level heart rate data from Fitbit devices of 14,489 participants in the All of Us national study. They identified bursts of elevated heart rate lasting 15 consecutive minutes or more to classify exercise timing, then examined health records for associations with cardiovascular disease and metabolic conditions while adjusting for age, sex, total activity level, sleep duration, smoking, and alcohol use. Compared with later-day exercisers, frequent morning exercisers showed 35% lower likelihood of obesity, 30% lower likelihood of type 2 diabetes, 31% lower likelihood of coronary artery disease, 18% lower likelihood of high blood pressure, and 21% lower likelihood of hyperlipidemia. Lowest rates of coronary artery disease were observed with exercise between 7 and 8 a.m. This was an observational study (not an RCT) showing association rather than causation; no conflicts of interest were reported in the coverage. Experts caution that people who choose morning exercise may also engage in other healthy behaviors, and consistency in physical activity matters more than exact timing. The CDC recommends at least 150 minutes of moderate-intensity activity per week plus muscle-strengthening activities. Source: https://www.healthline.com/health-news/morning-exercise-lowers-obesity-diabetes-risk