You tell John that if he wants to develop strength in his legs, he must focus on the principle of overload, which means that he must work his body, in particular his legs, with a greater workload than normal.John's body is used to his workout of light weights and high reps. If he wants to develop strength in his legs, he must increase his weights and workload to an intensity that enables him to only be able to complete three sets of eight reps. Exercises such as leg presses, leg curls, and squats are examples of exercises that can be used with overload to improve John's leg strength.
John's second goal is to become a better climber on hills. You recommend that he apply the principle of specificity, which means that, through specific practice, his body will adapt to whatever he wants it to do. If John wants to become a better climber, he must climb hills. Although the leg exercises will improve John's strength, they will not do as much to improve his climbing compared to him jumping on his bike and practicing climbing.Based on specificity, John's training should focus on getting him out on the road and tackling hills. John can choose a hill that he likes to ride but takes about 20 minutes to climb. On this hill he could practice climbing while using a low gear. He should pedal while seated for at least 3 to 5 minutes before pedaling while standing for 1 to 2 minutes, and then go back to sitting. John could do this type of interval training with the goal of spending more time in the saddle (seat), which will help him become a more efficient and better climber.
As John's fitness level improves and his workouts become easier, he will need to make more adjustments to his leg routine. The principle of progression says that he must progressively or gradually increase the workload for improvement to continue. Now that John's legs have adapted to his new workout, he must use the overload principle once again to progress to a new level of fitness. He might add more weight, increase the number of reps, lengthen the amount of time he does the workout, or try more difficult exercises.