The effect of beta blockers on heart rate response during the Chester Step Test

Abstract

The objective of this study is to ascertain that as the intensity of exercise increases through the stages of the Chester Step Test (CST) does the difference between the beta blocked(BB) and the non beta blocked(NBB) participants heart rate(HR) response increase. The study utilised a repeated measures design. Twenty males with a mean age of 58.9 (±6.1) taking Beta Blocker medication completed the CST on two occasions within one week of another. A further Seven males and thirteen females with mean age 61.5 (± 6.3) who were not taking Beta Blockers data from previous study data using the Chester Step Test was used to compare the HR and Rating of Perceived Exertion(RPE) responses at each stage of the CST. Each stage of the CST lasted two minutes after which HR and RPE were collected until the participant achieved 80% of predicted Maximum Heart Rate or RPE 15. HR was significantly different between the two groups at each stage of the CST p=<0.05. RPE was significantly different between the two groups at each stage of the CST p=<0.05. Limits of Agreement suggested test-re-test reliability of the CST for BB participants with the worse case HR being 11bpm above the mean in the final stage of the CST. The data suggests that as intensity of exercise increases as does the difference between the BB and NBB HR response. The data implies there may be some sex differences which will need investigating further. RPE was shown to be significantly different between the two groups. The data also showed that the CST is reliable for participants taking BB.