Question

the benefits of regular exercise are undeniable and extensive, ranging from weight control to improved mood to lengthened life. even a thirty - minute walk or quick trip to the gym releases neurochemicals that ease stress. exercise sets up a chain reaction that is generally a positive thing for the human body, preventing and controlling one health problem after another. however, endurance sports—activities that require the sustained effort of key muscles for long periods of time—reveal a darker side of exercise. the popularity of endurance sports has been trending sharply upward in recent years, and the consequences have been unfortunate. select the three supporting claims that the author makes to argue that though exercise is healthy, endurance sports can be harmful to the body. marathon running may cause temporary but severe kidney injury. ironman triathlon competitors are susceptible to many serious health problems. extreme endurance athletes do not live as long as people who exercise moderately. extreme cross - country skiers are at a greater risk of developing heart problems.

Explanation:

• The statement about marathon running causing kidney injury shows a harmful effect of an endurance sport (marathon running is an endurance sport).
• Ironman triathlon is an endurance sport, and the claim that its competitors are susceptible to serious health problems supports the idea that endurance sports can be harmful.
• The comparison between extreme endurance athletes (involving endurance sports) and moderately - exercising people regarding lifespan implies a negative aspect (shorter lifespan) of endurance sports.

Answer:

• Marathon running may cause temporary but severe kidney injury.
• Ironman triathlon competitors are susceptible to many serious health problems.
• Extreme endurance athletes do not live as long as people who exercise moderately.