Question

Describe specific ways your friend can use frequency, intensity, time, and type to safely apply the overload principles to his workout schedule. Provide two ways per training principle.

Sunday 30-minute bike ride
Monday 20 push-ups, 10 squats, and 20-minute jog
Tuesday 30-minute bike ride
Wednesday Rest
Thursday 20 push-ups, 10 squats, 25 curl-ups, and 20-minute jog
Friday 30-minute bike ride
Saturday One-hour walk

Answer 1

Sunday: instead of a 30-minute bike ride, reduce it to 20 minutes
Monday: 20 push-ups, 10 squats, and 10-minute jog
Tuesday: Instead of a 30-minute bike ride, reduce it to 10 minutes
Wednesday: Rest
Thursday: 20 push-ups, 10 squats, 25 curl-ups, and 10-minute jog
Friday: rest
Saturday: rest

Answer 2

Sunday -- start the week off strong, instead of 30 mins push for 45 to get that extra push or instead of 30 mins cut it to 15-20 mins of high intensity
Monday -- keep all of the workouts although add weights to build muscle faster
Tuesday -- make it 40 mins instead or keep it at 30 and go uphill
Wednesday -- resting is good, give your muscles time to recover
Thursday -- 20 min jog is perfect for a warm up, push your limits and double each workout, 20 push-ups? no. 40. 10 squats? no. 20. 25 curl-ups? no. 50.
Friday -- 30 min bike ride is good. Sprint as fast as you can to finish the week strong
Saturday -- one-hour walk is good though you should do this more frequently

To every exercise add weights.