The effect of talk test-based aerobic exercise on pulmonary functions and quality of life among adults with type 2 diabetes mellitus: a randomized controlled trial

Introduction
Talk test is widely accepted and costless subjective tool for exercise intensity prescription. However, its utility in diabetes rehabilitation is unexplored. Therefore, the objective of present study was to evaluate the effectiveness of talk test based aerobic exercise on pulmonary function test (PFT) and quality of life (QOL) among adults with Type 2 diabetes mellitus (T2DM).

Material and methods
90 patients were assigned to three groups: talk test group (TTG=30), rating of perceived exertion group (RPEG=30), and Control Group (CG=30). 8-wks of supervised training was followed by 4-wks of unsupervised exercise at home for both the experimental groups. Forced Vital Capacity (FVC) and Forced Expiratory Volume at 1st second (FEV1) were measures of PFT. QOL was assessed through World Health Organization Quality of Life-brief Questionnaire (WHOQOL-BREF).

Results
PFT improvement in TTG & RPEG is superior to CG. However, there is no significant between group difference (p>0.05). Further, the effect size in TTG was lesser than RPEG from baseline to 8-wk, 1.21 versus 1.46 and 1.42 versus 1.56 respectively for FVC and FEV1. However, it was more in TTG i.e. 1.26 and 1.08 in comparison to RPEG i.e. 0.51 and 0.57 respectively for FVC and FEV1 from 8-wk to 12-wk. The improvement in all the domains of QOL was significantly high in TTG & RPEG (p<0.01) as compared to CG.

Conclusions
The PFT and QOL among adults with T2DM can be improved through the aerobic exercise based on talk test. Additionally, talk test based exercise is more effective than RPE based exercise during unsupervised sessions.