With most 2020 races cancelled due to the pandemic, the nation’s runners, triathletes and OCR (obstacle course racing) enthusiasts will be feeling more ready than ever to experience the buzz of competitive racing and have something to train for. Fear not, this winter is filled with countless opportunities to push yourself beyond your limits. Here are 6 of the best:  Spartan Race Gritty, filthy and demanding, one of the world’s most famous obstacle races is returning