Heart rate deflection point as an alternative method to identify the anaerobic threshold in patients with type 2 diabetes

Aims

The purpose of this study was to evaluate the agreement between heart rate (HR) and treadmill velocity corresponding to the anaerobic threshold measured by second ventilatory threshold (VT2) and the HR deflection point (HRDP) in patients with type 2 diabetes.

Materials and methods

Thirty-two sedentary patients (56.1 ± 7.7 years) were evaluated. To determine the threshold values, patients performed an incremental treadmill test, with an initial velocity of 3 km h−1 for 3 min, which was then increased by 1 km h−1 every 2 min. The degree of agreement between VT2 and HRDP was analyzed using the Bland---Altman test.

Results

Patients had a HR of 133 ± 16 bpm at VT2 and 133 ± 18 bpm at HRDP. Mean velocity corresponding to VT2 was 6.3 ± 0.7 km h−1, and that corresponding to HRDP was 6.4 ± 1.1 km h−1. There were no significant differences between the methods evaluated (HR: p = 0.78; mean velocity: p = 0.57).

Conclusions

The present investigation concludes that there is an agreement between VT2 and HRDP methods for HR and treadmill velocity, and thus, either method may be used for these patients.