Tachycardia during resistance exercise: a case study.

A male weight-trained (WT) subject (A; age = 21 years, height = 193.6 cm, body weight = 113.4 kg, parallel barbell squat 10 repetition maximum [RM] = 183.7 kg) and a group of 18 similarly trained men (WT; X +/- SD; age = 24.7 +/- 3.0 years, height = 180.2 +/- 4.3 cm, body weight = 86.9 +/- 10.7 kg, 10 RM = 127.9 +/- 28.6 kg) were monitored during a barbell squat resistance exercise session (50% - 100% 10 RM) and a graded exercise test on a cycle ergometer. Compared with the WT group, heart rate (HR) for subject A was consistently > or =2 SD greater during resistance exercise (peak HR for 100% 10 RM = 212 b.min(-1) and 165.3 +/- 16.2 b.min(-1)). The graded exercise test resulted in similar HR responses for both A and controls. Subject A's augmented HR was present only during the pressure load of heavy resistance exercise, and not during the volume load of endurance exercise. The data suggest that subject A may be utilizing a different mechanism for heart rate regulation during resistance exercise.