I used to worry about the ideal mileage, percentage of increase in mileage, intervals, reps and sets, weights and progression, lifts, workouts, programs... it was very complicated.

我以前总担心理想的公里数、逐步增加公里数的比例、休息、几次几组、重量和增重过程、锻炼肌肉、各种日程安排。着实复杂得紧。