It may not be possible to have the body of a 20-year-old at 50, but it is possible for fit 50-year-olds to be as fit as 20-year-olds who don’t exercise, according to researchers at the K.G. Jebsen Center of Exercise in Medicine at the Norwegian University of Science and Technology in Trondheim.

Ulrik Wisloff, a professor and director of the K.G. Jebsen Center, says that activity is far more important than age in determining fitness.

The Center issued a press release earlier this month about its research.

Wisloff and colleagues have been looking at data from Norway’s biggest health database, the Nord Trøndelag Health Study (HUNT). They found that by increasing the intensity of exercise, people are able to reduce their risk of metabolic syndrome, the cluster of risk factors that increases the chances of developing type 2 diabetes, stroke and cardiovascular diseases.

Stian Thoresen Aspenes was recently awarded his PhD by the university for research conducted at the K.G. Jebsen Center. His thesis examined links between peak oxygen uptake, physical activity and cardiovascular risk factors among healthy adults aged from 20 to 90. He says:

“Physical condition is the most important factor in describing an individual’s overall health, almost like a report card.”

Aspenes used information from 4,631 healthy men and women taking part in the HUNT study. The participants had udergone lab tests of their peak oxygen uptake, also known as VO2peak, in 2007-2008. Researchers often use this measure as an indicator of overall fitness.

The HUNT study is thought to contain the largest database in the world of objectively measured VO2peak in healthy 20- to 90- year-olds.

By comparing the VO2peak measures with detailed information on the participants’ cardiovascular risk factors and various assessments of overall health, the researchers concluded that youth is not necessarily the most important factor when it comes to being fit.

They also found that the least fit participants also had the poorest measures of cardiovascular health, such as higher blood pressure and cholesterol.

The K.G. Jebsen Center research is reminiscent of the famous Dallas Bed Rest and Training Study, where in 1965, researchers invited 5 healthy 20-year-old men to stay in bed for three weeks and found this caused their peak oxygen uptake to drop by a massive 27%. But what was more surprising was what happened 30 years later when they followed them up.

Despite the fact they had gained an average of 23 kg (nearly 51 lbs), and doubled their body fat percentage, their peak oxygen uptake had only dropped by 11% compared to their pre-bed rest levels at age 20.

The Norwegian research takes the Dallas study a step further: it shows that fit 50-year-olds can be as fit as 20-year-olds who don’t do much exercise. Furthermore, it shows that exercise, especially the amount and intensity, is the key.

The Norwegian researchers looked at the impact of intensity of exercise versus duration and found intensity was far more important in determining peak oxygen uptake.

They have also looked at the impact of interval training, where short bursts of high intensity exercise are interspersed among short periods of lower intensity exercise. For example, four or more intervals of 4 minutes of high intensity, alternated with a similar period of lower intensity (the so-called 4×4 interval training).

They confirmed that this type of interval training is a quick way to increase overall fitness.

The researchers have also found that people whose VO2peak is low compared to those with higher levels, are more likely to have a cluster of cardiovascular risk factors.

They suggest keeping some level of physical activity is important. Even if you were active when young, this brings little benefit if you are inactive now, “you have to keep being active to get the health benefits from it,” says Wisloff.

Many of the researchers have built exercise into their daily routine. Aspenes, a father of three, now works full time at the Norwegian Directorate of Health. He gets his exercise by cycling to and from work every day. And living in hilly Trondheim, it means he can practise interval training, because as he puts it, “I ride like hell up the hills.”

One man who might serve as living proof of these findings, is 100-year-old Fauja Singh who stunned the world this week by completing a marathon in Canada. He finished the 26.2 mile Toronto waterfront marathon on Sunday evening in 8 hours, 11 minutes and 5.9 seconds, securing his place in the Guiness book of World Records as the oldest person, and the first centenarian, to ever complete a run of that distance.

The run on Sunday was Singh’s eighth marathon. He says his secret is that he eats a light diet comprising mostly tea, toast and curry, and he maintains a positive outlook.

Written by Catharine Paddock PhD