Fall race season is upon us, which means that many runners - from newbies tackling their first 5Ks to experienced marathoners - are amping up their training. It also means that injuries can be an issue.

To help runners avoid wrecking their bodies without sacrificing performance, Competitor magazine looked to ultrarunning legend Dean Karnazes for advice. Karnazes, the 50-year-old known for completing such challenges as the Badwater Ultramarathon and a 350-miler in 80 hours, along with once running across the country, shared three tips.

Don’t sit. Karnazes says he rarely sits during the day because it can weaken his posture. He prefers working at a stand-up desk.

Cross-train. Karnazes mentions such cross-training moves as push-ups, sit-ups and pull-ups, which help strengthen the body without the pressure of longer runs.

Pare down your sneakers. Karnazes believes that overbuilt running shoes can cause undue injuries by forcing the foot – and the body – into unnatural positions. “Just let the foot be the foot,” he says. To help make the adjustment, he suggests minimizing support slowly while adding foot-strengthening work into training.