1. Assessment of Exercise Intensity Formulas By Use of Ventilatory Threshold 
Goldberg Linn , M.D., Elliot Diane L. , M.D., Kuehl Kerry S. , M.S. 
CHEST 
Volume 94, Issue 1, Pages (July 1988)
DOI: /chest
Copyright © 1988 The American College of Chest Physicians Terms and Conditions

2. Figure 1
Predicted training heart rate (HR) formulas at 77 percent intensity compared with HR at the ventilatory threshold (VT) for the low-fitness group.
CHEST  , 95-98DOI: ( /chest )
Copyright © 1988 The American College of Chest Physicians Terms and Conditions

3. Figure 2
Predicted training heart rate (HR) formulas at 77 percent intensity compared with HR at the ventilatory threshold (VT) for the average-fitness group.
CHEST  , 95-98DOI: ( /chest )
Copyright © 1988 The American College of Chest Physicians Terms and Conditions

4. Figure 3
Predicted training heart rate (HR) formulas at 77 percent intensity compared with HR at the ventilatory threshold (VT) for the high-fitness group.
CHEST  , 95-98DOI: ( /chest )
Copyright © 1988 The American College of Chest Physicians Terms and Conditions