All of us have two ages: Our chronological age and our biological age. Our chronological age is the actual time we’ve been alive while our biological age is the rate at which we age on a cellular level.
“Most of us have all had the experience of being surprised to find out that someone is far younger than we had imagined — for instance, when an individual we thought was in their late 50s turns out to actually be in their mid-40s,” Dr. Terry Grossman, founder and medical director of the Grossman Wellness Center in Denver, explained for Everyday Health. “And, by the same token, we will occasionally discover that someone is considerably older than we had guessed. The reason for these discrepancies is often because their biological ages are different than their chronological ages.”
Dr. Rhonda Patrick did a podcast called ‘Sauna use and Building Resilience to Stress’ where she talks about hormetic stress. Dr. Patrick states “Almost all the primary causes of aging have stress at their root. Inflammation is a prime example and in fact it’s been identified as one of the key drivers of the aging process . . . . However somewhat paradoxically, stress isn’t always bad. Short term stress can result in a reduction in long term chronic stress – in other words we can build resilience. This is because short-term exposure to stress can strengthen the cellular response mechanisms in the body to stress. This is called hormetic stress.”
We are familiar with hormetic stress but probably don’t even realize it. Exercise is a type of hormetic stress, as is cold stress (think ice bath) and – you guessed it – heat stress. By laying in an infrared sauna for 15-45 minutes, our body increases its production of heat shock proteins as a result of the heat stress. These heat shock proteins have been shown to help repair damaged proteins and protect DNA.
One study done by the National Institute for Food and Nutrition found that:
‘Centenarians, or people who live to be at least 100, tend to have an increased expression of heat shock proteins – the same proteins that are produced in a sauna.’
Another similar study done by Ball State University found that the “longevity Gene” – FOX03 – is also activated by heat. People with a higher expression of FOX03 genes are more likely to live to 100. 
We can’t control our chronological age, but we are in total control of our biological age with regular use of infrared sauna.