Background/AimsPhysical activity (PA) is associated with a reduced risk of colorectal cancer. Thus, we examined the colon transit time (CTT) according to the physical activity level (PAL) in Korean adults.MethodsThe study subjects were 49 adults: 24 males and 25 females. The subjects used an accelerometer for 7 consecutive days to measure the 1-week PAL. The subjects took a capsule containing 20 radio-opaque markers for 3 days. On the fourth day, a supine abdominal radiography was performed. According to the total activity count of all study subjects, the upper 25%, middle 50% and lower 25% were classified into the high (H), moderate (M) and low (L) physical activity (PA) groups, respectively.ResultsThe total CTT was significantly longer in the female (25.8 hours) than in the male subjects (7.4 hours) (P = 0.002). In regard to difference on PAL, although there was no significant difference among the male subjects, the right CTT in the female subjects was significantly shorter in H group than in M group (P = 0.048), and the recto-sigmoid CTT was significantly shorter in H group than in L group (P = 0.023). Furthermore, there were significant differences in total CTT between L and M groups (P = 0.022), M and H groups (P = 0.026) and between L and H groups (P = 0.002).ConclusionsThe female, but not male, subjects showed that moderate and high PAL assisted colon transit.

BackgroundThis study examines the relationship between physical activity (PA), sedentary behavior (SB) and body weight in Korean adolescents.Methods:This study used a nationally representative sample of 72,368 South Korean adolescents, aged 13 to 18 years. The study sample was categorized according to BMI as follows: underweight, body mass index (BMI) <18.5; normal weight, 18.5 ≤ BMI < 23.0; overweight, 23.0 ≤ BMI < 25.0; and obese, 25.0 ≤ BMI. An analysis was then performed to determine if meeting the recommended guidelines for PA frequency (5 times/week ≤) and amount of SB (<2 hours/day) was associated with weight category.Results:The percentage of normal weight adolescents was 54.3% while the percentages of underweight, overweight, and obese adolescents were 27.4%, 10.2%, and 8.1%, respectively. Significantly fewer underweight and obese adolescents met PA guidelines compared to normal weight adolescents. In addition, underweight, overweight, and obese adolescents had significantly higher SB scores.Conclusion:The present study indicates that in Korean adolescents, physical activity and sedentary behavior are independently associated with weight status. Overweight, obese and underweight Korean adolescents should all be independently monitored for management of health-related behaviors.