Chronotype & HRV

The past couple entries discussed training & its relation to heart rate variability (HRV) and chronotype. Well, what about the effects of chronotype on HRV? Recent research reveals ‘evening people’ have a higher perturbation of their autonomic nervous system (ANS) by training in the first part of the day in comparison to ‘morning people’. Specifically, these athletes showed a slowed vagal reactivation and higher heart rate (Vitale et al., 2019) in the morning training sessions. These results are in line with previous studies (Vitale & Weydhal, 2017) concluding ‘morning people’ report a lower perceived exertion, demonstrate less fatigue & have better physical performances than other athletes of different chronotypes in these early sessions. Training bouts later in the day appear to have similar effects on ANS activity in all chronotypes. A caveat to training later in the evening would be the potential sleep disruptions that may occur in all chronotypes. It’s worth being mindful of the timing and your chronotype when scheduling workouts and tracking the subsequent perturbations in HRV to promote the greatest training adaptations.