Apec Editor

Tri-set training involves performing three exercises consecutively with no rest in between. It is crucial that all three exercises target the same muscle group, but not necessarily the same muscle.
Tri-set training with the shoulder complex, for example, would target the anterior deltoid, lateral deltoid, and posterior deltoid. We want to avoid training different areas of the body, such as the shoulder, leg, and back, when doing Tri-set training. Why? because the goal of Tri-set training is to overload specific muscle groups, not the whole body. Because there is no rest in between, removing the rest is more taxing on the neurological system, so muscle recruitment is utilised to its full potential throughout the session.

Density training sometimes referred to as circuit training is the result of two very specific training variables: volume and duration (time). Volume refers to your total workload or the number of sets and reps you perform in a given workout; duration refers to how long your workout lasts. The density of a session is then calculated by combining these two variables.
By increasing the amount of work you do in a given amount of time, you improve your work capacity which is the goal of density training.