I am from Guatemala, a country in Central American. I have 2 sons who love football and Manchester United, they are 12 and 11 years old. Because their age they don't have an email or facebook acount, so they ask me to speak out for them.
They want me to ask you: "When they play at their games they get tired early in the match. They want to get better and be more resistant, they want to be faster and stronger... What kind of exercise can they do?
They both train in football club, but they want to improve in their game, so they taught to ask to the best, you....
Which of the following would you like to improve?: