The researchers ran fitness and brain tests on 75- and 80-year-olds from that decade and compared the results to 75- and 80-year-olds three decades ago. Based on the results, today's aging population is healthier than their age group used to be.
Walking speed, reflex speed, language proficiency, thinking and working memory of both study cohorts were monitored. While the participants were the same age at the time (1990 compared to 2018), the latter group was far more lively.
To break it down, adults from the past decade ran an average of 0.2 to 0.4 meters per second faster. They also had faster reflexes, including a 5 to 25% improvement in grip strength and a 20 to 47% improvement in knee extension.
Along with the significant increase in fitness, the researchers found positive increases in cognitive functions. Verbal language skills were 12% higher among 75-year-olds in 2018 and 47% higher among 80-year-olds in 2018.
"Performance-based measurements describe how older people are coping in their daily lives, and at the same time the measurements reflect their own functional age," says lead researcher Taina Rantanen, Ph.D., in a press release.
So people don't literally age the other way around than Benjamin Button, but their physical and cognitive skills represent a younger functional age – especially when compared to generations before them.