Older athletes offer a master class on aging

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At last month's Boston Marathon, Vancouver's Yul Kwon crossed the finish line first in the men's over-80 age category – one of nine Canadians older than 60 to earn top-three age-group honours at the race. It's a familiar pattern: Following the lead of record-setters such as 85-year-old marathoner Ed Whitlock and Olga Kotelko, who held 26 age-group records in sprints, jumps and throwing events when she died at 95, Canada has some of the top masters track and field athletes in the world.

In addition to their prowess on the track, these athletes offer a unique opportunity for researchers to study what they call "elite aging": the best-case scenario in our universal battle against the passage of time. A new study in the Journal of Applied Physiology, from a team of researchers at five Canadian universities, is the latest to poke and prod top masters competitors in an attempt to understand what makes them unique, and what the rest of us can learn from their example. Here are some of their findings, plus outcomes from other recent investigations into age-defying athletes:

MUSCLE

The new study, led by Dr. Geoffrey Power of the University of Guelph, tested the shin muscles of 14 accomplished athletes with an average age of 80, including seven reigning world-record holders in events ranging from sprints to the marathon.

The researchers were interested in how signals travel from the brain to the muscles. Most of us start losing "motor neurons," the command centres in our spines that control bundles of muscle fibres, in our 30s. Runners in their 60s, Power and his colleagues had previously found, still have just as many motor neurons as people in their 20s. But would the same hold true at the age of 80, when muscle is declining most rapidly?

The octogenarian athletes, it turns out, had lost some of their motor neurons, but still had about 40 per cent more than healthy non-athletes at the same age.

They also had more robust neuromuscular transmission, ensuring that signals from the brain reached the muscles as intended.

The message? Size isn't everything with muscles: Regular exercise will also help ensure that you can actually use the muscle you've got.

DNA

The Tor des Géants is an epic 330-kilometre footrace through the Italian Alps, with a total elevation gain nearing the height of Mount Everest. Its finishers are a hardy bunch, and they're not necessarily young – at least chronologically.

A recent study in the journal Mutagenesis, by researchers at Italy's National Research Council, took saliva samples from Tor des Géants finishers to determine their telomere length. Telomeres are the segments of DNA that protect the ends of chromosomes; they gradually get shorter each time a cell divides, until they get so short that the cell can no longer function normally. As a result, telomere length is considered a crucial cellular marker of biological age.

When the subjects were divided into three groups by age (younger than 39, 39 to 53, and older than 53), there were no significant differences in telomere length. That's very different from the pattern seen in the non-athlete control group, where telomere length declined with age. The over-53 runners had telomeres that were 40 per cent longer than similar non-runners.

While the evidence about links between exercise and telomere length remains preliminary, the new results fit with several previous studies that have found longer telomeres in masters athletes. And it's worth noting that former elite athletes who stop training don't end up with longer telomeres: to keep your cells young, you have to keep exercising with the enthusiasm of youth.

BRAIN

A good workout makes you feel sharp; so what does a lifetime of dedicated training do for your cognitive powers? That's what a team of researchers at the University of Pittsburgh, led by Dr. Vonda Wright, investigated in a study published in February in The Physician and Sportsmedicine.

Wright and her colleagues assembled a group of 51 masters athletes between the ages of 40 and 80 who trained for sports such as running, cycling, rowing, and swimming, averaging five days of exercise a week. Then they gathered a group of sedentary controls with similar age and socioeconomic characteristics.

To measure brain function, they deployed the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) system, a widely-used battery of computerized neurocognitive tests. Sure enough, the masters athletes scored better than the controls on verbal memory and reaction time, with no difference in visual memory or visual-motor speed scores.

Scientists are still debating exactly how exercise affects the brain, but Wright and her colleagues cite evidence that regular exercise may raise levels of brain-derived neurotrophic factor, which in turn helps maintain the size of key brain areas like the hippocampus. And they plan to continue monitoring their subjects to see if the brain benefits become even more pronounced as the athletes and controls age.

Together, these studies bolster an already strong case for the benefits of lifelong participation in sports. And if you've already stopped, it's never too late to restart: Kwon's path to the top of the podium in Boston started only when he entered his first race, a 10K, at the age of 59.