Dr. Fredrick Peters, September 27, 2017
Have you ever heard of the wet-bulb globe temperature (WBGT)? This measurement takes into account temperature, humidity, wind speed, sun angle, and cloud cover. It’s sort of like that “feels like’” temperature you see on the weather report. It’s 84°F outside, but it feels like 95°F
I mention it because recent research connected increasing WBGT caused by climate change to a decrease in physical activity. The study, which sourced data representing more than 1.9 million Americans, found a negative relationship between physical activity and higher WBGT.
It isn’t too surprising that temperature increases would cause people to exercise less, but what is surprising are the effects the hot and/or humid environments exacerbate physical exertion and increase core body temperature. In extreme temperatures, sweating is not always sufficient to avoid heat strain and heat stroke.
For some people, heat stress can start at a WBGT of 72-79°F. The capacity for physical activity starts to decline at a WBGT of 78°F, and any physical activity becomes nearly impossible at 104°F. A sedentary lifestyle can have dire effects. It is one of the leading risk factors for global disease and responsible for 5.3 million premature death per year worldwide.
Just this week, parts of Ohio saw a WBGT of 83°F. The temperatures were great enough that, on Monday and Tuesday, Columbus City Schools closed early and cancelled athletics and extracurriculars. Already, hotter temperatures are causing kids to lose critical opportunities to participate in physical activity.
If the WBGT continues to increase, as climate change projections predict it will, the greatest impact will be on the obese and the elderly, who are respectively seven times and four times less likely to be physically active in hotter climates.
In light of recent events, specifically the withdrawal of the United States from the Paris Climate Agreement, I am making it my personal mission to both help the environment and promote physical activity. I even responded to the US withdrawal from the Paris Climate Agreement with an offer of free services for those who are doing their part to combat climate change.
Simply put, the environment directly impacts fitness and physical activity. In more ways than one, it is the major public health issue of our time. It’s time we do something to promote both a healthy environment and population. Let’s get it done!