Possible Clues:

• Endurance shown by southern girl touring America
• Hanging on
• Strength enlivens pirouettes lacking in energy
• Therapist, am I napping to conserve energy?
• Marathoners’ need
• I'm Santa, moving around, showing ability to keep going
• Ultramarathoner's asset
• Floor coverings rolled back in area displaying grit
• Sit awkwardly with a man, revealing bottom
• Endurance refitting mast in Antarctica, primarily