Will the hot weather ever end?As I write this, the temperature is a balmy 102 degrees and headed up toward the 105 we saw a few days ago.
Although we were tricked into believing the ‘cooler and wetter’ El Niño forecast because of the great weather in May and June, we’ve had dry and oven-like conditions since mid July.
Cyclists and runners have been subjected to four consecutive weeks with most daily high temperatures soaring to 100 degrees or above and a few days exceeding heat advisory criteria.
People doing bike or run workouts have coped with rivers of sweat leaking through saturated sweatbands, salty sweat obscuring vision and stinging sunburned skin and routinely losing 3-5 pounds of fluid during long workouts even when hydrating constantly.
Some athletes have avoided the heat by getting out early in the morning when the air temperature is (comparatively speaking) cooler at 80 degrees or so, while others have suffered through workouts later in the day in 100 degree or higher temperatures when readings on road surfaces are 110-120 degrees.
One local cyclist training for an upcoming event has sacrificed sleep to get up at 4 a.m. and do his workouts before daylight, while other people have strategically planned running routes so they can stop at friendly houses along the way for a cool ‘water hose shower’ and drink of water.
Post-workout time has revolved around rehydrating with a cold fermented beverage (or two) while dreaming about relocation to a cooler mountain climate.
Micheal Decker, a staff meteorologist with the local National Weather Service office, said that although temperatures may “moderate” slightly over the next week or so, the hot weather isn’t going away soon.
“The area of high pressure that’s parked over our area is typical for this time of year,” said Decker. “The heat could stay with us on into September until the hours of daylight get shorter and cold fronts start moving through.”
There may be hope on the horizon, noted Decker, but not for the near future.
“Although the eagerly-awaited El Niño weather pattern hasn’t had much of an impact on summer temperatures and rainfall, the long range forecast suggests that we’ll possibly see cooler and wetter than normal weather during November, December and January,” Decker said.
Cooler and wetter than normal? Bring it on, please.
Athletes training and competing in the hot weather of the past month may have also noticed that in addition to copious amounts of sweat and the associated dehydration, you have to work harder to maintain a given pace while biking or running compared with doing a similar workout in cooler conditions.
Several heat-related issues contribute to that feeling, but the most significant are increased skin blood flow to aid with cooling (moving body heat to the surface), reduced blood volume because of sweating and less oxygen due to lower air density during hot weather.
As the body works to reject heat and stay cool, there is increased blood flow to the surface of the skin to carry internal body heat to the surface where it can dissipate via sweat.
This shift of blood to the surface combined with loss of total blood volume due to increased sweating means that less blood is available to working muscles and vital organs such as the heart, making exercise more difficult. Decreased blood volume to the heart decreases cardiac filling and stroke volume, so the heart rate increases to sustain the workload. The net result is that a moderate level of exercise in cool weather may feel significantly harder at higher temperatures.
In addition to reduced blood volume and a corresponding higher heart rate, the high temperature air we breathe during exercise also has less oxygen (for a given intake volume) than cooler air due to the density altitude.
Density altitude is pressure altitude corrected for nonstandard temperature, so as temperature increases the air density will decrease. Decreased air density (or a higher density altitude) during hot weather has the same effect on an athlete as being at a higher altitude
As an example, the elevation in San Angelo is about 1,850 feet above sea level. If we calculate density altitude for this location based on hot mid summer conditions of 102 degrees, a barometer reading of 30.05 and a dew point of 54 degrees, the effective altitude that our body feels is almost 5,000 feet or close to the same elevation as Denver.
The effect of the higher density altitude due to high temperature is that less oxygen is taken in with each breath, so our muscles produce less power.
So, getting back to the initial question — will summer ever end? It always does (eventually) and so we can all look forward to that perfect bike or run day when the temperature is around 50, there’s no hot wind and a light mist is falling.
Until then, we’ll all suffer in the heat, drink copious amounts of fluids, struggle with the higher density altitude and look forward to the promised El Niño.
Upcoming Events
Sept. 19-20: Fort Davis Cyclefest, pbbatx.com/cyclefest/
Sept. 26: Armydillo Run, https://secure.getmeregistered.com/get_information.php?event_id=122340
Sept. 26-27: Texas State Championship road race, txbra.org/events/event.asp?EventID=229
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