Heat And Humidity
According to research, runners start to slow down past 55 degrees, and start suffering at 65 degrees. When humidity is thrown into this mix, the slow down is even more dramatic. Going out too fast in extreme heat and/or humidity can even cause heat injury.
Therefore in high heat and humidity, the prudent runner starts off at a pace he can maintain, perhaps as much as 30 seconds per mile slower than normal. Galloway recommends slowing your goal pace by 3-5 percent in 60 to 70 degree temperatures; 7-12 percent in 70 to 80 degree temperatures; and by 20 percent above 80 degrees.
How many of us are guilty of flying off at a suicidal pace in the first mile or two of a 10K because we were so excited?
“The longer the distance, the more energy conservation and muscle recovery come in to play,” says marathoner Ann Armstrong. “Spend it early and you will be miserable in the end.”
With competition, our adrenal glands dump large amounts of stress hormones like adrenalin into our bloodstream, causing us to start far too quickly. So hold yourself back and start very slowly — up to 30 seconds slower than your desired race pace. Don’t worry about losing time this way — you’ll make it up when it counts later in the race.
While Armstrong doesn’t intentionally go out fast, it often happens.
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“Getting ahead of your splits early in a race is generally not money in the bank,” she says. “My best races have been when I hold back in the first half — sometimes to the extent of near tedium — and then pick up in the second half.”
Start with runners of your ability, not faster. If it’s a large race, avoid weaving in and out of the runners. Settle into your desired goal pace somewhere around the first mile. Keep things under control until you’re past the first 2 miles in the 10K and 5 miles in the half marathon.
Armstrong advises that beginning runners “don’t get too excited and go out too fast. Don’t get caught up in whatever pace others are keeping. Take it easy in the beginning and you will enjoy the finish a lot more and surprisingly you’ll probably be faster.”