Because they know when they are full and satisfied. They dont have Control over what they eat. But how much they eat.
A skier can benefit from a training program because it could help them become better at skiing.
The activities performed in programs (such as a skiing training program) helps the person taking the course build their body strength and prepare for any upcoming games. Think about football practice. Why do they go to practice all of the time? They are going to prepare and get better at football. The same thing applies to skiing.
Answer: his pain when using the restroom
Explanation: His grades and difficulty obtaining a job are irrelevant. His aching tooth should be discussed with his dentist.
Hope this helps! :)