Everybody Gives You Different Suggestions. Last Week When I Was At The gym, I Asked A Personal Trainer That Question. And He Suggested Two Type of Exercise When Doing Two Muscle Group.He Also Suggest One Large Muscle Group With One Small Muscle Group. He Recommended Chest With Tricep Since The Chest Workout The Tricep. You Can do Back and Bicep Together. Then Shoulder and Legs Together.i Mean The Combination was Good Yesterday I asked Another Trainer That Same Question And He Recommended Doing Opposite Muscle Groups For Example Chest And Back One Day. Tricep and Bicep Second day. Shoulder And Traps Third Day. So He Had a Different Perspective. I mean Those Are Good But it’s Difficult to Exercise Especially Chest And Back. So It’s Really Depending on You and Your Workout Routine And Who You Train With. However, if You Really Want to Gain Some Muscles Then I Will Recommend Doing These Workout. The Workout That i Been Doing and it’s Been Working. DAY 1: Shoulder, Chest and Tricep. DAY 2:Off: DAY 3: Back And Bicep. DAY 4:Off: DAY 5 Legs. DAY 6: Abdominal. DAY 7 Off. So it’s 4 Day Workout 3 Day break. The Schedule Can Remain More or Less I can Change it and switch it The Next Week During The Exercise it Depends on Your Mood You Want to Have Good Result go Heavy 45 min You Want to be Sore Then You relax your muscle Eat Good Healthy Food. You Can’t Just Workout And Not Watch Your Diet.You Can’t Workout Your Muscles Seven Days A Week You Have to Give Your Muscle a Break. Hope You Like My Muscle Group Combo.