Possible Clues:

• It's downhill for sporty people when runners jump
• Runners jump on inclined surface
• Where you're expected to go downhill
• Part of nursery, perhaps, where runners bound along
• Street scene?
• Decline in need of a fall?
• Big Sky feature
• Runners stride then dash downhill
• Clumsily kiss and run in winter sports venue
• Look into adjusting spikes for a smooth run