What is the technique used to express or validate how a client feels when he or she is working during exercise?

RPE method.

Explanation:

Exercise is the best way to maintain the fitness of the body and also helps to reduce the risk of a disease. Different exercises are performed by the individuals depending on the needs of the people.

The client feeling during the exercise can be validated by the RPE ( rate of perceived exertion) method. This method can be identified by putting the load on an athlete. The session intensity must be multiplied by the duration of the load in the RPE method.

Thus, the answer is RPE method.

personal-

communication, mobility, cooking, using the telephone, cleaning the house, doing laundry,   going to the bank, and managing medications.

social-

music, art groups, cooking and gardening. outdoor activities are shopping, eating out, theatre trips and sailing.

ethical-

honestly, integrity, loyalty