Why do you faint after a marathon?

What is the life expectancy of fibreglass vaulting poles for pole vault? How do you install front brakes on a bike? If you light a tennis ball on fire will it explode? Is tennis a plural noun? Who are the Wimbledon linesmen? What are the advantages of steel bikepacking bikes compared to other materials for long-distance off-road cycling adventures? What side is deuce on in tennis? Who is dame kelly Holmes married to? What is alternative name for leotard? Is it illegal to move forward during a tennis serve? What is mean velocity gradient? How many shots are fired for a false start in track? What are the best features to consider when purchasing a folding bike that is non-electric? The first roll of the bowling ball knocked down 3 of the 10 pins what percent of the pins were still standing? How many golf balls do you usually use in a golf game on average? How will you decide who gets to serve first in badminton? Can you use a mountain bike on the road? How often should a helmet liner replacement be done to ensure optimal safety and protection? What is a bicycle made for two named? Who begins serve at the start of a new set in tennis?