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Is Running Outside Better Than the Treadmill? Here’s What the Research Says
A small PLOS One study found that 12 highly trained male runners who ran at least five days a week, averaging about 40 to 50 miles, had higher energy and oxygen costs and worse running economy outdoors than on a 1 percent incline treadmill, with differences most apparent near the second ventilatory threshold (about a 7:10 to 7:22 pace).
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