Upper body muscles groups are used for throwing, climbing, lifting items up or pushing them forward, and pulling/rowing.
Guiding Principles
Order: Perform movements that use multiple muscle groups and are more complex at the beginning of your workout.
Balance: Make sure that you perform a pulling movement for each pushing movement. Paying attention to and working out the muscles of your back and back of the shoulders helps you create or maintain a healthy posture while preventing injury.
Progression: When you are able to perform 2-3 more repetitions than your target number of repetitions you can gradually increase the resistance by 5% to 10%.
Rest: If your goal is muscular endurance, then you should reduce your rest time between sets whereas if strength is your goal, then you may want a slightly longer rest break in between sets or exercises. Alternating exercises (ex. Push ups and Inverted Row) or performing a circuit is a strategy that allows some muscle groups to rest while others are working for a time-efficient workout.
Periodization: Doing the same exercises, repetitions, and weight will eventually lead to stagnation. Establishing some variability in your workout will allow you to master the movements while forcing your body to adapt and keep workouts interesting.
Recovery: Proper nutrition and sleep help your body recover and build muscle. Muscle-building exercise creates some mild inflammation, and your body’s repairing of those muscles results in stronger muscles. Letting muscle groups rest 24 to 48 hours after a workout will help your muscles recover. The American College of Sports Medicine recommends those new to weightlifting engage in 2-3 sessions of weightlifting per week with these workouts occurring on nonconsecutive days.