Donna Is a 70-Year-Old Retired Physical Education Professor

Donna is a 70-year-old retired physical education professor. She has been physically active all of her life, but over the last year, she has been busy traveling and has not been exercising at all except for her walking tours around international cities. Donna enjoys all types of physical activities, especially walking, weight lifting, rowing, hiking, racquetball, and tennis. Donna would like to get started on a regular routine of exercise. Answer the following questions to help her develop an appropriate fitness plan.
Donna would like to train at a moderate intensity. What percentage of her MHR should she train at?

A) 20%
B) 40%
C) 50%
D) 80%
E) 100%