問答題：請以至少 50 字說明，為何 NASM 的最佳化運動表現訓練模式（OPT model），其多樣化的內涵讓人可以用系統化的方式來設計並執行訓練課表，並且適用於不同目標的個案。
Human body needs time and specific stress to adapt and progress for both musculoskeletal and neuromuscular system. In addition to common endurance-strength-maximal strength-power phases, OPT model's phase 1 provides a great base for motor control and awareness for posture and movements, which lead to good kinetic chain all the way to phase 5.
Moreover, for resistance training, OPT model is good for proprioception enhancement, enlargement of skeletal muscle fibers, activation and optimization of energy systems. For plyometric training, OPT model takes landing mechanics and technique development into account. Despite having different goals, solid foundation is of great importance to achieving goal as well as avoiding injuries.
問答題：請指出一種訓練動作，可以適用於多種 OPT model 的層級（level）。
Multi-Level Exercise: Push-Up
NASM's Optimum Performance Training (OPT) model™ is a systematic, integrated, and functional training program that can be used with a majority of client types.
Resistance training within the OPT model is used to increase muscular endurance, strength, lean body mass, and power. Although clients' goals will differ, resistance training is a vital component of an effective exercise program.
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