Do Cardio Fitness Level and Body Mass Index During the Teenage Years Predict Disability in Men Later in Life?

It’s no secret that the twin epidemics of obesity and physical inactivity are a significant issue not only for the adult population, but for children and adolescents as well.

The combination of social media, video games, being driven just about everywhere by parents, and optional or non-existent physical education in schools, as well as a seemingly never-ending exposure to fast food has resulted in all-time high rates of obesity among young people.

This current situation gives rise to an interesting and important question. Do fitness and body weight status during the teenage years have any association with the risk of disability later in life? To help answer this question, researchers published results on over one million Swedish male adolescents between the ages of 16 and 19, who were drafted into the military between 1972 and 1994.

Body mass index (BMI) and cardiorespiratory fitness level were measured at baseline. BMI was classified as Underweight, Normal Weight, Overweight, Class 1 Obese, Class 2 Obese, and Class 3 Obese*. Cardiorespiratory fitness was classified as Low, Moderate, or High Fit based on results from a maximal exercise test using a stationary bicycle ergometer**. The sample was followed for an average of 28.3 years, during which time 54,304 men were granted a disability pension by the Swedish government. The results were as follows:

• When compared to those in the highest 10% of cardiorespiratory fitness, those in the lowest 10% were nearly 4 times more likely to receive a disability pension later in life.
• When compared to those in the Normal Weight category, those with Class 2 or Class 3 obesity were approximately 2.5 times more likely to receive a disability pension later in life.
• Within each BMI category, those who were High Fit were substantially less likely to receive a disability pension later in life compared to those who were Low Fit.

Taken together, these results indicate that the BMI and CRF status of male teenagers is strongly associated with future risk of disability. The authors acknowledged that a limitation of the study was that BMI and CRF were only measured at baseline, and suggested that future similar studies measure these two variables over time.

The authors also stated that these results underscore the position of the American Heart Association that CRF should be considered a vital sign.

*Underweight: BMI<18.5 kg/m²
Normal weight: BMI 18.5-24.9 kg/m²
Overweight: BMI 25.0-29.9 kg/m²
Class 1 Obese: BMI 30-34.9 kg/m²
Class 2 Obese: BMI 35-35.9 kg/m²
Class 3 Obese: BMI >=40 kg/m².

**Low Fit: bottom 20%, Moderate Fit: 20-80th %, High Fit: top 20%.

Reference

Henriksson, P., Henriksson, H., Tynelius, P., Beglind,D., Lof, M., Lee, IM, Shiroma, E., Ortega, F. (2019). Fitness and Body MassIndex during Adolescence and Disability Later in Life. Annals of Internal Medicine, doi:10.7326/M18-1861.

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