In resistance training it is important for high school students to understand the principles of training. Which of the following applies the principle of progression?
1) Beginning resistance training by using ballistic stretching before exercising.
2) Beginning resistance training by holding stretches for 15 seconds and working up to holding stretches for 60 seconds.
3) Beginning resistance training by increasing the number of repetitions every day.
4) Beginning resistance training with increasing the weight lifted and increasing the number of repetitions.
