Effect of baseline status on cardiovascular responses post-isometric handgrip exercise

Abstract Background Isometric handgrip (IHG) exercise causes changes in heart rate variability (HRV) and hemodynamic responses with individual differences. We test the hypothesis that baseline measurements affect post-exercise outcomes. Methods In this cross-sectional study, 45 males aged 17 to 22 were enrolled from SMS Medical College, Jaipur, India. Hemodynamic and HRV data were collected at baseline, during, and after 5 minutes of IHG exercise. Nonparametric tests compared the absolute and relative responses before, during, and after the exercise. The relationship of baseline measurements with outcomes was evaluated using Pearson's correlation. Results The study showed a significant increase in the absolute values of hemodynamic parameters and LF/HF ratio during and after 5 minutes of IHG exercise compared to the baseline. However, a significant decrease and increase occurred in all the relative hemodynamic parameters and most HRV parameters, respectively, after rather than during the 5 minutes of IHG exercise. Hemodynamic parameters significantly correlated with baseline during and after 5 minutes of IHG exercise. Similarly, baseline affects all the HRV parameters during IHG exercise, but not after 5 minutes of IHG exercise. Conclusion The present study concludes that initial baseline status should be considered while evaluating the post-IHG exercise responses.