Most athletes are surprised at how fast they can comfortably run 120m .
A key to feeling good is to either jog the remaining 280m slow , or walk 100m , then jog 180m until the next 120m .
Most athletes are surprised at how fast they can comfortably run 120m , yet a key to feeling good is to either jog the remaining 280m slow , or walk 100m , then jog 180m until the next 120m .