Exercises that utilize both concentric and eccentric contractions in which force is generated against resistance while the muscle is changing in length are called:

progressive resistance exercises.  

Explanation:

Progressive resistance exercises are the exercises that are performed to increase the muscular strength of the body. In these exercises the participants exercise their muscles against a resistant surface or object. This process increases the strength progressively. The material used in progressive resistance exercises includes the machines, elastic bands and free weights. These type of exercises involve both concentric and eccentric contractions.

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