Briefly construct a 3-week workout routine that incorporates the fitness principle of overload.

Answer:

Week 1: Do a 20-minute brisk walk three days this week and two full-body strength sessions, completing 1 set of 10 repetitions of each exercise (such as squats, wall push-ups, and lunges). Week 2: Keep the same schedule, increase the walks to 25 minutes, and complete 2 sets of 10 repetitions in the strength sessions. Week 3: Walk for 30 minutes three days this week and complete 2 sets of 12 repetitions in the strength sessions. Warm up before exercising, cool down afterward, and take rest days between strength sessions. The gradual increases in duration and repetitions apply the principle of overload.