Final answer:
The statement is true; six METs signify that a person is working six times harder than when they are sitting quietly, as METs are a measure of energy expenditure compared to a resting state.
Step-by-step explanation:
The statement that six METs require you to work 6 times harder than sitting quietly in a chair is True. MET stands for Metabolic Equivalent Task, and it is a unit that estimates the amount of energy used by the body during physical activity, compared to resting metabolism. One MET is the rate of energy expenditure while at rest, so six METs mean you are expending energy at six times that baseline rate.