Hot Girl Health Literacy, Issue 1: What dose of walking do you really need for your hot girl walks?
aka where I use my PubMed Access and you get to have more health literacy around what wellness culture sells us
Welcome to my first post in a series I hope to build into Substack and the eventual Zine, which I am dubbing Evidence-Based Wellness, in which I use my skills working in medicine to discuss a wellness factoid that’s circling the internet, and we review where it came from, what is true, and what’s been exaggerated. For my paid subscribers, this will be in the January edition of the zine, so if you’re wanting to wait for formatting and read the mag all at once, I’d skip this article.
Today we are addressing one of the most popular New Year's resolutions, and that is getting 10k steps a day (I will only briefly touch on people touting 15k steps a day). Now, the point of this series is not to say XYZ wellness thing is BAD BAD BAD, but rather to offer you the nuance of the science where recommendations come from, so that you get more agency AND the understanding of where the science is at, and what might make living in your body more comfortable.
Today, we will be reviewing a large meta-analysis from 20221, that looked at 47,000+ subjects on the correlation between health and walking, specifically steps in a day averages across life spans and risk for mortality (read: likelihood of dying).
One of the reasons this met analysis was done was to enter the conversation that was already ongoing about if 10k steps was truly needed, as it is a bit of pop health advice that has been around for decades now. The 10k number, though, didn’t come from research, but rather from a marketing campaign in Japan for a pedometer. From an article studying older women and walking in 20192:
“It likely derives from the trade name of a pedometer sold in 1965 by Yamasa Clock and Instrument Company in Japan called Manpo-kei, which translates to “10 000 steps meter” in Japanese.”
General truisms in wellness often come from a half truth, or a half-right interpretation of the data, and where there is no data (which isn’t uncommon, especially when it comes to women’s health), there is passed down wisdom. I’ll say here that just because there hasn’t been a study yet does not mean something does not work, but where there are studies, we should take them into consideration.
Back to walking. In the 2019 paper, prior to the 2022 paper, a gap had been identified in what was known about walking and health: What’s the minimum effective dose to impact people’s health in a way that matters (ie, if walking x number of steps only gets you 1 more week of life, the finding can be statistically significant but not clinically or IRL important to you). From this gap, this 2019 study sought to find what’s called the dose-response curve, which gives us an average view of how different “doses” or number of steps for walking correlates with health outcomes.
You may be asking yourself, why does this matter? From a population level, it matters that people have the correct information, as this may inform whether they do any walking, a lot of walking, or no walking at all. If you think, for example, that there are only health benefits when walking 10k or above, and you’re a busy new parent, or someone who struggles with chronic pain, than that high number may feel out of reach, and you don’t try to have a step goal at all. If, however, 5k steps will reduce morality risk by a big percent, you may try. What feels like semantics, when scaled to public health communications becomes either a helpful truth from what we know OR a misleading barrier.
See how I forced you into some public health learning before I gave you the answer? Yes, that was on purpose. Anyhoo, in the 2019 they had around 18,000 women 45+ years old wear step counters for 7 days. They collected this data for different cohorts from 1992-2015 (ie, they get a week of step data for each person). They then compared this step data by following the women as a group for years after the initial data was collected, mainly for mortality (ie, notification of death).