103-year-old Lil Hansen is clear that yoga is key to her long life – and not just practicing it. Every Wednesday, Lil drives to her local senior centre and leads 30 other seniors in their yoga class. As Vickie Collins, director of the Michigan centre, says ‘Reaching 103 is amazing, but reaching 103 and still driving and doing yoga is truly amazing.’

Lil herself is more self-effacing: ‘I make it up as I go,’ she says. ‘As long as they enjoy it, I will enjoy doing it. They’re not ready to get rid of me yet, so I have to stick around for a while.”

Her class has been running for 30 years, taking a break only last year as Lil recovered from a fall in which she broke her hand, knee and foot. She also credits yoga with helping her recover.

Plausibility rating: 5 out of 10. Lil is by no means alone in claming yoga as one of the keys to longevity. We can dismiss some of the more outlandish claims – of yogi who lived to over 200, or even 300, years old – but there is plenty of evidence that yoga has a positive effect on aspects of physical health such as balance and flexibility.

Practitioners of yoga also talk about effects on mental heatlh such as stress, depression and anxiety, and one study by Richard Brown and Patricia Gerbarg suggests that yogic breathing (pranayama) could potentially have a positive effect on factors associated with longevity. One 92-year-old yogi says ‘Take it from me, a regular, dedicated yoga practice is the key to a long and health life.

Overall, though, there’s surprisingly little hard evidence that yoga improves lifespan (more on this in a later post here). But here’s the thing: people don’t practice yoga because they want to live longer, they do it because they want to live better. If they get a few extra years, that’s a bonus. And, as we’ve seen before, having a motivation, any motivation – whether it’s taking a yoga class or teaching one – can be more important than its precise nature.

As Lil says of her teaching: ‘It makes me get up in the morning.’