Related Clues:

• Fires up lacking energy and strength
• Ability to keep going makes lively mounts expend energy
• It develops with a man's indefatigability
• What marathon runner needs reproductive parts in bloomers?
• Enduring ability -- in a man, it's exceptional
• A bird under good man showing energy
• Endurance of maiden protected by a saint when converted
• Works for Disney, keeping up no end of verve and persistence
• Power switch at mains
• Sustained energy at mains somehow
• A rug's taken up when holding in grit
• Energy of bird, second to last virtually
• Bottom of street -- a main turning
• It's a man running, showing staying power
• Good man with a bird showing vigour