Broadcast live from the hallowed halls of the Anatomy Museum in Trinity College, Dublin, Growing Up, Live continued its fascinating deep dive into the wonders of human life by delving into the murky waters of ageing.

Last night's episode completed the three-episode run of the ground-breaking show, and probed into the realities of ageing, the secrets to ageing well and why there are different kinds of ageing. 

It will come as a frustration to many fitness fanatics that for all the squats, lunges and infrared saunas you do, it's only looking after one kind of system while another continues to age, often unattended to. This is the difference between chronological age - your age in years from the day you were born - and biological age - how old your body seems in terms of health and fitness. 

There are many factors that influence your biological age, such as being overweight, smoking, excessive drinking and a generally poor lifestyle. Professor Niall Moyna, Head of Sport and Exercise Physiology in DCU’s School of Health and Human Performance, explains that "the two don't always match". 

In last night's show, we met two men at varying levels of fitness and age and followed along as they found out their chronological ages and their biological ages, which made for emotional moments. 

To see the results and to find out how to lower your biological age, watch the video above! 

Watch back on Growing Up, Live on RTÉ Player now.