Wednesday, August 18, 2010

How to beat the heat and humidity

 A former railway bridge across the Scugog River is now a footbridge.

The weather one day last week threw me an unexpected challenge—the prospect of a training walk on a particularly hot and humid day.
     I had decided to alter my program in the final weeks leading up to the 42-km marathon on September 26 and the 120-km, four-day hike in October. I would do fewer but longer walks: 20- to 30-km each, three times a week, with rests or cross-training exercises in between.
     I went to bed early planning to start out at 5:30 a.m. for a 25-km walk. In the middle of night, I had a better idea. I would do just a 13 km walk on a favourite route in the morning and a dozen km in the afternoon. I had a meeting to attend in downtown Lindsay in the afternoon. It seemed sensible to walk along a 12-km round-trip route, rather than drive. The idea was particularly appealing when my alarm clock sounded at 5 a.m. I set it back for an extra hour of sleep.
     The morning haze was as heavy as fog when I set out at 6:30. My route took me along nice neighbourhood sidewalks for a few blocks, across a pair of small parks, and down a short paved trail to the start of the Victoria Rail Trail that stretches 90 km north to Haliburton. But I turned south along more sidewalks, across the city’s swankiest residential area (it’s not very big) then to a trail along the west bank of the Scugog River to downtown. A pair of bridges here cross the Scogog to a another rail trail that stretches 30-km south to Bethany. The first short section of this rail trail hugs the east bank of the river. On early summer mornings the Scugog is a mirror reflecting big willow trees, houses and a pair of footbridges. On this hazy morning, the images are reflected in a smoky mirror.
     For a long morning walk, on the return I would normally head north on the Victoria Rail Trail, adding 10- to 15-km to the trip. Instead, I walked straight home in anticipation of the second walk in the afternoon.
     Early afternoon brought a temperature of 31C., not that formidable for a relatively short walk. But the humidity approached 100 percent and the humidex—the temperature it actually feels like—hit 41, according to the TV weather channel.
     Dr. Gabe Mirkin, former competitive marathon runner, author of 10 fitness and diet books, and publisher of an e-zine for uber exercisers and sports buffs, offers some advice on how to handle exercise in hot weather. For racers, Mirkin says, “Start out significantly slower than you usually do and gradually increase your effort to keep yourself from slowing down.” When the weather is hot, the heart has to dissipate heat from the muscles by pumping it to your skin and the extra work limits “how much blood it can pump to bring oxygen to muscles and you have to slow down.”
     Mirkin also recommends salt and sugar for hot weather exercise. Excessive salt consumption can cause severe health problems, but Mirkin says, “If you exercise regularly for more than a couple of hours, particularly in hot weather, you need extra salt. You also need more sugar in hot weather to increase endurance… We drink Pepsi and eat salted peanuts on long [bicycle] rides in the summer.”
     Probably good advice. But I had a better idea. Why seat it? Instead of walking to that afternoon meeting, I drove there in our air-condition car then spent in the rest of the day in our air-conditioned bungalow. Seems a more sensible way for old geezers, especially one with a slightly bum heart, to beat the heat and humidity.
     It was cooler this week, so I did both the morning and afternoon walks

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