A new study has revealed 34 percent of girls and 41 percent of boys aged 16 are at risk of poor heart health.
The teens failed to meet the minimum level of fitness needed for optimal heart health.
These low fitness levels can increase the youths' chances of developing chronic diseases, such as high blood pressure and type two diabetes, warned the study's experts.
The research, based on data collected during last year’s Irish Life Health Schools Fitness Challenge, also reveals a steady decline in fitness levels as students’ progress through secondary school.
The worrying trend has emerged with one in five first-year boys failing to meet the minimum fitness levels required for good heart health, and then this number doubling to 41 percent when they reach the age of 16.
Additionally, a similar result was seen for young girls, eight percent of 12-year-old girls do not meet the fitness criteria, and it increased to a third of 16-year-old females.
According to the experts, first-year boys should be able to run at least 32 shuttles in order to meet minimum fitness levels required for good heart health, and first-year girls should be able to run at least 15 shuttles.
However, the fitness specialists said it isn't all doom and gloom; Fitness decline is not inevitable, and improvements can be made in a matter of weeks.
Over 30,000 students participated in the six-week Irish Life Health School Fitness Challenge last year, and first-year students saw an average of eight to 10 percent improvement in their fitness levels.
The biggest difference in performance was seen in at-risk, low-fit teenagers, further demonstrating the importance of early intervention for Irish teenagers, said the study.
Commenting on the research, Prof Niall Moyna, Head of the School of Health and Human Performance, Centre for Preventive Medicine in DCU said: “We really can’t ignore the fact that more than a third of 16-year-olds in Ireland are now at risk of developing premature cardiovascular disease."
"The impact on their long-term health and our healthcare system is undeniable. The progressive decrease in fitness seen in boys and girls as they progress through post-primary school is alarming and should be a wakeup call for parents, teens and healthcare professionals.”
The professor concluded by encouraging students who are not physically active or doing any organised sport, to give it a try!