Elderly people walk 1mph faster than they did 30 years ago due to better nutrition, hygiene and improved health care, a study has found.
A group of 75-80 year olds born between 1938 and 1939 travelled up 0.4 metres per second (0.9mph) faster on average than a second group of the same age range born between 1910 and 1914, the researchers found.
The 1930s cohort also demonstrated greater levels of grip strength and knee extension strength, the study at the University of Jyväskylä in Finland revealed.
Speed and strength improvements were found to be most pronounced when comparing 80-year-old women from the two groups.
Better access to quality nutrition and health care, combined with improved levels of hygiene, explain the difference, according to Kaisa Koivunen, a PHD student who co-authored the study.
“The cohort of 75- and 80-year-olds born later has grown up and lived in a different world than did their counterparts born three decades ago," she said.
“These include better nutrition and hygiene, improvements in health care and the school system, better accessibility to education and improved working life."
Between 1989 and 1990, the researchers asked more than 500 men and women to walk 10 metres in a corridor at the Sport and Health Laboratory at the university.
A distance of five metres was allowed for acceleration and the volunteers, wearing either walking shoes or trainers, were encouraged to continue for a few metres past the finish line.
This experiment was repeated in 2017 with a second group of 726 volunteers.
Researchers carried out interviews with the two groups and asked them to grade their health in the last year on a scale from 'poor' to 'very good'.
Participants were also asked to describe their rate of physical activity, with options ranging from 'mostly sitting and resting' to 'regular strenuous exercise'.
Volunteers in the 1930s group reported being more physically active, which is believed to have contributed to their increased walking speed.
Their increased muscle strength was partially attributed to them being taller and heavier than their earlier counterparts.
The researchers said this could be explained by high levels of deprivation and social instability during the early 1900s in Finland.
Children worked from an early age and experienced the turmoil of the Russian Civil War in 1918. They later fought as young adults in the Second World War.
By contrast the group born in the 1930s experienced widespread governmental reforms to nutrition, including the provision of school meals for all children free of charge and longer obligatory education.
A prolonged period of higher education likely delayed their entry into manual labour, reducing their risk of future health problems in later life, the study found.
Greater opportunities for sports and physical leisure activities for the 1930s group may have also contributed to their increased walking speed, the researchers said.
"Higher physical activity and increased body size explained the better walking speed and muscle strength among the later-born cohort," said Ms Koivunen.
"Whereas the most important underlying factor behind the cohort differences in cognitive performance was longer education."
Professor Taina Rantanen, who co-authored the study, added: "This research is unique because there are only a few studies in the world that have compared performance-based maximum measures between people of the same age in different historical times.”
"The results suggest that our understanding of older age is old-fashioned."