Answer: perform; energy; unfit
Step-by-step explanation:
Physical fitness is the ability to (perform) daily tasks vigorously and alertly, with (energy) left over for enjoying leisure- time activities and meeting emergency demands.
It is the ability to endure, to bear up, to withstand stress, to carry on in circumstances where an (unfit) person could not continue, and is a major basis for good health and well-being.
Physical fitness is simply regarded as a state of well-being. It can be achieved with physical exercise, proper nutrition, and sufficient rest.