Alex didn't notice Claire's plight as he went to collect their race t-shirts and get some water for both of them. He frowned when he came back and noticed her condition though.
"You okay?"
"I…don't think I can move," she admitted. She was afraid of collapsing if she even tried.
He immediately crouched down in front of her so she could get on his back. "Hop on. That wasn't even a workout for me so I can carry you perfectly fine."
Claire knew Alex wasn't simply boasting. He hadn't broken a sweat the entire time they were running and looked as energetic as he had before they started. She would wish she had his stamina if she wasn't painfully aware of how he got it in the first place.