An upper-body-lower-body training plan (Upper-Lower) is a so-called split training plan. Unlike a full body split training plan, in a split plan the training is divided into several training days on which different muscle groups are trained.
An Upper-Lower plan is a two-way split, usually with 4 days per training week. That is, you divide your muscles to be trained into two muscle group categories. One day you train all the muscles of the upper body, and then on the next day you train all the muscles of the lower body.
Unlike a full body training plan, an upper/lower split allows you to train your muscles at a higher volume per workout. As a beginner, a full body training plan is recommended. After a few months you can switch to an Upper-Lower plan.
One advantage of the two-way split for many athletes is the focus on the lower body. Since every 2nd workout is a lower body workout, you'll be using your leg muscles a lot.
As a rule, you train 4 times a week, so that you work all muscle groups 2 times each every week. The training sessions are either constant or divided into A and B training days.
On A and B workout days, the muscle areas you focus on can vary. For example, if on upper body day A you focus more on back training, on upper body day B you can focus more on chest training.
For the lower body workout, you could focus on the quads in the first workout and the hamstrings in the second workout.
You can also train 3, 5 or even 6 times per week with an Upper-Lower plan. However, all muscle groups should ideally be trained at least twice per week.
It is important that you train the large muscle groups first and then the smaller ones. So train your chest and back before you train your shoulders and arms. Only in exceptional cases should small muscle groups be trained before large ones, e.g. if your shoulders are a weak point.
With the Alpha Progression App you can get an ideal Upper-Lower body workout plan to build muscle optimally.