How many steps per day it takes to stay healthy
If you thought exercise was just for your heart or figure, you’re wrong.
Yes, exercise supports a resilient cardiovascular system, but it is also the primary way our lymphatic or immune system migrates throughout the body. Lymph nodes are connected by lymphatic channels, and unlike the cardiovascular system, there is no pump (heart) constantly moving your virus-kicking, cancer-fighting white blood cells around for you. YOU moving YOUR body is HOW your immune system travels and works. It’s the total enchilada. You don’t get one without the other.
Exercise has profound effects on the optimal functioning of our immune system. Although prolonged periods of strenuous exercise can depress immunity, study after study show that regular moderate exercise is hugely beneficial. A single 20 minute session of mild to moderate intensity effectively redistributes white blood cells across the lymph nodes, bloodstream and peripheral tissues. In fact, single bouts of moderate intensity exercise have even been used to effectively increase vaccine responses in “at-risk” patients. Researchers attribute these positive effects to overall reduction in inflammation, enhanced immunosurveillance and the healthy aging of immune cells in a regularly-moving body. Exercise has shown to improve overall health outcomes in our elderly population and patients living with cancer and chronic viral infections such as HIV (PMID: 26477922).
Physiology lesson over.
How many steps you actually need
So with Fitbits and Apple watches and trackers motivating all of us to get out and go, I often get asked by my clients, “How many steps should I aim for?” Perhaps you live a hectic life and cannot imagine committing to a specific time for regular movement, but are willing to wear a wrist monitor to inspire some extra laps around the parking lot or taking the stairs instead of the elevator. Every step counts, right?
These wrist bots give you a dopamine-rushing high-five when you hit 10,000 steps, but with very busy lives – is there any TRUE benefit to going “that extra mile” for most of us? If we set the goal too high, sometimes we are paralyzed from making the effort at all. Or worse even, this is famously seen in crash dieting and the rebound that often causes us to gain even more weight back than we lost.
A JAMA 2019 prospective cohort study tested the association between exercise, measured as steps per day, and all-cause mortality (so what was the correlation between “steps” and odds of death). This was a 4 year study done on over 18,000 women. What they found was that women who averaged less than 2,700 a day were at the highest risk for death of any cause. There was a 41% reduction in this risk if they increased their count to 4,300 a day. Mortality rates continued to decrease up to 7,500 steps a day but leveled off after that (PMID: 31141585).
So this study implies you can decrease your risk of death by 41% in walking only 4,300 steps a day. Not 10,000. And that the max benefit related to all causes of death basically caps at 7,500 steps a day. Don’t those numbers sound like feasible goals for the average American?
And even understanding a reasonable target helps me take reasonable steps (get it?) to hit a life-saving goal. So if you get home from a long day with “only” 4000 steps, I encourage you to move a little more. Hitting anywhere between 4,300 and 7,500 gives you the optimal decrease in all cause mortality and is completely feasible even in this fast-paced world.
Hope that’s helpful, and happy stepping!
Sources:
1. Simpson RJ, Kunz H, Agha N, Graff R. Exercise and the Regulation of Immune Functions. Prog Mol Biol Transl Sci. 2015;135:355-80. doi: 10.1016/bs.pmbts.2015.08.001. Epub 2015 Sep 5. PMID: 26477922.
2. Lee IM, Shiroma EJ, Kamada M, Bassett DR, Matthews CE, Buring JE. Association of Step Volume and Intensity With All-Cause Mortality in Older Women. JAMA Intern Med. 2019 May
