We aim to examine the relationship between metabolic risk (MR) profile and physical activity (PA) with an adult within the household. A total of 4761 schoolchildren (54% boys) aged 10–16 years old were categorized as either at high MR or low MR profile based on their weight and systolic blood pressure status. We assessed the frequency of PA with an adult within the household and fitness. Multilevel regressions were used to determine the likelihood of being at MR in schoolchildren. The proportion of males and females who engage in PA with adults daily was 17.4% and 10.4%, respectively. 16.5% male and 17.2% female did not engage in any PA with adults at all. Compared with those engaging in PA daily with adults in their household, schoolchildren who have reported no such PA were 54% (OR 1.54, 95% CI, 1.07–2.20) likely to have an elevated MR profile. Those who sometimes do PA with adult were 25% (OR 1.25, 95% CI, 0.82–1.93) more likely to have a higher MR profile. After adjusting for PA and fitness, PA with adults remains a determinant of MR profile in males. Compared with those that reported they daily did, schoolchildren were more likely to be unfit if they either sometimes engaged in PA with adults (OR 2.11, 95% CI, 1.44–3.09) or never (OR 2.89, 95% CI, 1.89–4.43). Joint PA with an adult within household could increase schoolchildren's fitness level and may reduce the risk of metabolic diseases.