I have been doing TR for week now and have been really enjoying the variety of workouts. I feel better on the bike already. Last night I did the Pettit workout, while I was reading the instructions that pop up it said to throw in some form drills like form sprints, speed endurance intervals or quadrant drills. I have tried to find some clarifications as to what I am exactly supposed to be doing here but am still a little unsure.
Could anyone please help explain these to me it point me to a good guide so I can add then next time