Read the following paragraph, which is from the introduction to a technical document. Then answer the questions that follow.
"If you're just starting to learn about fitness, well, it's about time. This guide to nutrition and exercise is useless without actually changing the food you eat and getting off your couch, so don't think that just by reading it you'll suddenly lose weight and feel better. You have to put in the time and the effort, and if you do, you'll feel like a whole new person. Now put down those chips and let's get started."
How would you describe the tone of the passage? Where are some phrases in the passage that show this tone?