by Bianca Garilli, ND
Physical inactivity prevalence among adolescents aged 11-17 years was estimated to be 81% globally in 2010, where insufficient physical activity (PA) was measured as < 60 minutes of moderate-to-vigorous-intensity PA daily per WHO guidelines.1 As part of the 60 minute/day exercise recommendation, the US Department of Health and Human Services recommends that aerobic activity should be incorporated at least 3 days/week, muscle-strengthening at least 3 days/week, and bone-strengthening activities at least 3 days/week.2
It is well known that physical inactivity increases the risk of various chronic diseases including heart disease and type 2 diabetes (T2D),3 so much so that a new phrase has emerged – “Sitting is the new smoking” – referencing the harmful nature of too little PA. There is no shortage of data linking inactivity to the global burden of chronic disease, due to the relationship between sedentary behavior and overweight and obesity, as well as impaired glucose metabolism and insulin resistance.4-5
Not as well studied, however, is the connection between physical inactivity from youth to adulthood and the risk of adult onset chronic disease. A study published in Medicine & Science in Sports & Exercise aimed to learn more about the association between persistent physical inactivity vs. activity during the childhood-to-adulthood transition and impaired glucose metabolism in adulthood.6 Longitudinal data from 2,000 individuals in the Cardiovascular Risk in Young Finns Study with baseline ages of 3-18 years were separated into 4 groups based on leisure-time PA habits during childhood/adolescence: persistently low PA, decreasingly active, increasingly active, or persistently active.6
Repeated follow-ups occurred between 1980-2011; researchers examined associations between PA levels in youth and impaired fasting glucose (110-124 mg/dL) or T2D in adulthood. Results showed the following prevalence of impaired glucose metabolism as adults according to PA level as youth:6
- Persistently low PA: 16.1% with impaired glucose metabolism as adults
- Decreasingly active: 14.5% with impaired glucose metabolism as adults
- Increasingly active: 6.8% with impaired glucose metabolism as adults
- Persistently active: 11.1% with impaired glucose metabolism as adults
Additionally, when compared to the persistently low PA group, there were 53% and 30% reduced risks for impaired glucose metabolism in the increased PA and persistently active groups, respectively.6 No such risk reduction was seen in the decreasingly active group.
The study’s authors concluded that persistently low PA from youth to adulthood is associated with an increased risk of experiencing impaired glucose metabolism in adulthood and thus increased risk of developing metabolic syndrome, heart disease, and T2D.6 Even a moderate increase in PA can lower the risk of adult onset metabolic abnormabilites.6 Therefore, maintaining a regularly active lifestyle beginning in childhood and maintained into adulthood is an important lifestyle habit that should start young and be encouraged at all ages.
Why is this Clinically Relevant?
- Physical activity starting in childhood is an important step in promoting health later in life
- Physical inactivity during childhood increases the risk of impaired glucose metabolism in adults6
- Daily, habitual physical activity should be encouraged for all youth, with inclusion of aerobic and bone- and muscle-strengthening activities
- WHO. Prevalence of insufficient physical activity. http://www.who.int/gho/ncd/risk_factors/physical_activity_text/en/. Accessed August 10, 2018.
- CDC. Physical Activity Facts. https://www.cdc.gov/healthyschools/physicalactivity/facts.htm. Accessed August 10, 2018.
- Gonzalez K, Fuentes J, Marquez JL. Physical inactivity, sedentary behavior and chronic diseases. Korean J Fam Med. 2017;38(3):111–115.
- Amati F, Dube J, Coen P, et al. Physical inactivity and obesity underlie the insulin resistance of aging. Diabetes Care. 2009;32(8):1547-1549.
- Hamburg N, McMackin C, Huang A, et al. Physical inactivity rapidly induces resistance and microvascular dysfunction in healthy volunteers. Arterioscler Thromb Vasc Biol. 2007;27(12):2650–2656.
- Kallio P, Pahkala K, Heinonen O. Physical inactivity from youth to adulthood and risk of impaired glucose metabolism. Med Sci Sports Exerc. 2018;50(6):1192-1198.