After 56 minutes, the second runner has traveled 56/7 = <<56/7=8>>8 miles.
Similarly, the first runner has traveled 56/8 = <<56/8=7>>7 miles.
Therefore, the two runners are 8 - 7 = <<8-7=1>>1 mile apart when the second runner stops.
Thus, the second runner can stop for a maximum of 8 minutes, which is the amount of time it takes the first runner to travel 1 mile.
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