Most young kids who play sports or keep active do so just for the fun of it. And many who don’t probably have no regard for how it will affect them later. But new research from the University of Jyväskylä in Finland found low youth fitness is associated with higher risk of cardiometabolic diseases in middle age.

That means the inactivity of today’s youth could translate into more people experiencing heart problems earlier than would normally be expected. The results of this 45-year longitudinal study were published recently in the Scandinavian Journal of Medicine & Science in Sports.

Researchers looked at data from the fitness tests of those aged 12-19 and combined it with the incidence of diabetes, hypertension and coronary heart disease along with self-measurements of waist circumference from those same participants at ages of 37-44 and again at 57-64.

Cardiorespiratory, muscular and speed-agility fitness was measured against diseases and risk factors and a cardiometabolic risk score was developed. The results showed that low cardiorespiratory fitness when the people were young equated to a higher burden of cardiometabolic conditions between the ages of 57-64.

For example, women with low cardiorespiratory fitness in their youth were at greater risk of high blood pressure later in life and men who scored low on the speed-agility tests were more likely to have higher waist circumference in middle age.

"Other common cardiometabolic disease risk factors such as age and body mass index were controlled for in the analyses, so we can conclude that cardiorespiratory fitness is an independent early indicator for cardiometabolic health later in life," said researcher Perttu Laakso.

Researchers said the their results confirm what was previously observed using data from the conscription register of men for the Swedish military.

"There have been publicly discussed concerns over how the deteriorating fitness of young people will affect the future labor force," Laakso said. "This study gives us some scientific evidence to support that concern. Unfortunately, there is little sign of this concern being alleviated, given that the cardiorespiratory fitness level among today's adolescents has been shown to be significantly lower than that of the adolescents examined in this study."

Laasko said it’s important to make an investment in increasing the physical activity of younger generations in order to lessen the chance of health problems later in life because, "The economic cost of these investments will be far lower than the related health care or disability expenses caused by cardiometabolic diseases."

He also said all is not lost if people miss out on the benefits of activity at a young age because evidence shows that exercising at any age lowers the risk of cardiometabolic diseases.

Click here to read more in the Scandinavian Journal of Medicine & Science in Sports.