Researchers at the University of Leicester, who studied the genes of 400,000 Britons, found a clear link between walking faster and a reduced biological age.
Participants were recorded walking quicker, defined as those who walked faster than 4mph - had longer telomeres, which are the 'caps' at the end of each chromosome.
Simplified: these telomeres hold repetitive sequences of DNA that protect the chromosome from damage, similar to the way the cap at the end of a shoelace stops it from unravelling.
Each time a cell divides, these telomeres become shorter - until a point where they become so short the cell can no longer divide.
Scientists see the length of the telomere as a marker of biological age, independent of when someone was born and linked to a range of symptoms we associate with ageing, such as frailty.
Based on the results, the researchers estimate that a lifetime of brisk walking could reduce an individual's biological age by as much as 16 years by midlife.
The new findings confirm that adopting a brisk walking pace 'actually causes better health' and is 'likely to lead to a younger biological age', he said.
Additionally, experts believe speedier walking is a marker of better musculoskeletal health, heart and lung fitness, activity levels, motivation and mental health.