Monitoring morning heart rate variability in an elite female long jumper with ulcerative colitis during the build-up to the 2020 Tokyo Olympics: A 58-week case study

This case study describes longitudinal morning heart rate variability (HRV) and its relationship with ulcerative colitis (UC)-related events in an elite female long jumper with UC over 58 weeks. Morning HRV was self-measured for 3 min supine using a Polar H10 sensor and the Elite HRV application. The natural logarithm of the root mean square of successive differences (LnRMSSD), its 7-day rolling mean (LnRMSSD rolling), and the coefficient of variation of LnRMSSD (CV LnRMSSD) were calculated. Training Load was quantified using the session-rating of perceived exertion method, subjective condition was assessed using Hooper's score, and a smallest worthwhile change (SWC) band aided interpretation of short-term HRV changes. LnRMSSD rolling fell below the SWC band during the Germany-based period (weeks 18–31), around the Asian Athletics Championships in Qatar (weeks 40–41), and during part of the pre-hospitalization period. Prior to hospitalization (week 50), LnRMSSD was lower during the second half of monitoring and declined stepwise from the 2019 competition phase to pre-hospitalization, with a further drop and increased CV LnRMSSD immediately before hospitalization. Training Load and Hooper's score did not show progressive increases across the pre-hospitalization period. Morning HRV may offer useful complementary information for conditioning and decision-making when interpreted alongside Training Load, subjective condition, self-reported UC-related symptoms, and competitive context. Although morning HRV is not a diagnostic marker of clinical UC activity, this case study provides, to our knowledge, the first longitudinal description of HRV changes in relation to fluctuations in condition in an elite athlete with UC.