What's the Right Dose of Exercise: AKA - The Hiking Club has it Right

April 20, 2015

What’s the Right Dose of Exercise?   AKA: The Hiking Club Has it Right 

 Reference:   New York Times, JAMA Internal Medicine April 2015J Am Coll Cardiogy Feb 2015Annals of Inter Med Jan 2015Harvard JAMA Internal Med 

 “A day without exercise is as bad as a day of smoking!”   Ever heard that?   Tim Cook called it “the new cancer”.   Being a couch potato is risky.   So tempting, but risky.   But how risky?   It’s so lovely and convenient to veg out and watch TV and be lazy.   To act differently, I need to know the benefit. 

What is the benefit? This is the research. The data.   Follow 204,542 Australians, ages 45-75 followed for 9 years for death rate, while getting precise data on amount and type of exercise – that’s the database.   That is 1,444,927 person-years of mortality data in the study. That big a study has credibility.   There were 7,435 deaths in that time range, again a big number.   

The second study from Harvard followed 661,137 people with 116,686 deaths from ages 21-98.   Again, pretty credible. Most health organizations and the government recommend you get about 150 minutes a week of moderate exercise.   Against that backdrop, these two major studies compared the mortality of non-exercisers, those who met the guidelines, those who exceeded them a little, and those who exceeded them a lot.   If you exercise a little but don’t meet the 150 minutes guideline, you reduce your risks of death about 20%. Those who exercise the full recommended 120 minutes a week reduced their mortality by 31%.    Wow. That’s a lot. But it’s not the best! Those who exceeded the recommended exercise by triple or 450 minutes a week (little over an hour a day) reduced their mortality by 39%.   And finally, those few who exercise more, up to 10 times more, didn’t get any more benefit, and in fact declined back to the level of those meeting guidelines.   So, the sweet spot is an hour a day.   

The Australian study adds a bit more by looking at the intensity of exercise. For those who got sweaty less than 30% of their exercise time over those who were just walking got an additional 9% of benefit. If they got sweaty for over 30% of their time, they got a 13% extra benefit. If you want to get sweaty, what about jogging?   

A third study called the Copenhagen Study looked at the optimal benefit obtained from jogging. They found a U shaped curve that showed maximum benefit from light and moderate jogging, meaning 1.0-2.4 hours a week of jogging was best, with as much as a 78% reduction in mortality for slower running, not too often (2-3 times a week).   Strenuous joggers had no benefit over non-jogging.   (Did you get that? NO benefit.) 

 And compared to being sedentary?   The study in Annals shows that prolonged sitting is its own risk, all by itself.   And prolonged sitting of 8 hours a day essentially erases the benefit of daily exercise.   So walking an hour, then sitting 8 hours ends up with no benefit. That makes your elevator quote: “An hour a day keeps the doctor away, as long as you don’t sit for 8 hours. 

 WWW. What will work for me?   It looks like the Wisconsin Hiking Club has it right.   They organize 4-6 mile hikes 5 times a week allowing you to walk two three times a week, get your seven hours of walking in while having the company of friends and community encouragement. I’m a member and closing in on my 1,000-mile award. Add that to my dog walking, my evening strolls,          and an occasional morning run, and I’m close to making the perfect formula to optimal health and longevity. Exercise is something magic. If I could just find a way to do some heavy lifting, and stop sitting so much at work.   But then I would be insufferably self-righteous.   But you, my friends and readers, are welcome to join us in the Hiking Club. We’re essentially free and have visitors on almost every hike. Just be at the destination listed online 10 minutes early because we leave on time.   

 Pop Quiz

  1. Being a couch potato is dangerous, in and of itself?   T or F                       Answer:   T, it's Deadly.
  1. The recommended weekly exercise of 150 minutes is the best formula for health and longevity. T or F                      Answer:   False.   It’s only a third – but don’t get me wrong. It’s wonderful for you. But best is an hour a day of walking.
  1. Getting sweaty for 30% of the time is better than just casual walking?   T or F               Answer:   True
  1. If I run daily, I should run slowly, three times a week. T or F                     Answer:  That seems to be the best.
  1. Running an hour a day is better than 20 minutes, twice a week.                 Answer:  False, it’s as bad as not running at all
  1. Hiking can be free! T or F                        Answer:  True.   Join Us!