In a perfect world, you could make it to the gym 5 days a week. In the real world, you might get to the gym 3 days this week, 2 days next week, then 5 the next. Be prepared with a plan that will work all body parts and get you in and out of the gym in 40 min. or less.
A circuit style routine works best. Pick one exercise for the Chest, Biceps, Triceps, Abs and call this round Circuit A, then pick one exercise per Legs, Shoulders, Back and Abs and call this round Circuit B. You will complete each circuit 3 times, using your ab exercise as active rest. Once you complete the abs set, immediately begin your next round. Complete Circuit A 3 times, then move to Circuit B and repeat for 3 rounds.
If you plan circuits for 3 different days, you can alternate them during the week, ideally leaving one day of rest in between workouts.
Body part Exercise Reps
Chest Push Up 15-20
Biceps Hammer Curl 15
Triceps Tricep Kickback 15 per arm
Abs Bicycle 60 (total)
Legs Jump Squat 15-20
Shoulders DB Shoulder Press 15
Back Lat Pulldown 15
Abs Exercise Ball Crunch 25
When planning the next circuit workout, use a difference exercise per body part. For example, if you did push ups in your first workout, then do dumbbell chest presses the next gym day. This insures that you are hitting your muscles from all angles for optimum training.
As you get more comfortable with the program, increase the intensity by adding either reps or heavier resistance.