High-intensity interval training and thromboembolic events during chemotherapy for testicular cancer: a retrospective analysis from the Body & Cancer cohort.

Background: Men with testicular cancer receiving platinum-based chemotherapy have an increased risk of thromboembolic events, with incidence rates between 8-24%. A recent trial evaluating the effect of high-intensity interval training (HIIT) prematurely closed as three out of nine participants (33%) in the intervention group developed a thromboembolic event. The purpose of this retrospective cohort study was: 1) (primary) to evaluate the incidence of thromboembolic events in men receiving chemotherapy for testicular cancer who had participated in HIIT during a 6-week exercise program ( Body & Cancer) 2) to describe the feasibility of this program. Material and methods: Forty men who had participated in at least one HIIT session from February 2007 to February 2020 were included. Electronic medical records were searched for incident thromboembolic events (arterial and venous) during Body & Cancer and up to one-year post-chemotherapy. Attendance, cardiorespiratory fitness (VO 2 -peak), and upper and lower extremity muscular strength (1 repetition maximum (RM)) were obtained from the Body & Cancer database. Results: One participant developed a thromboembolic event during Body & Cancer . No participants developed a thromboembolic event in the follow-up period. In all, data represent 160 HIIT sessions with a median attendance of eight sessions [range 1-19]. Statistically significant increases in upper and lower extremity strength were observed (8.6 (4.2 to 13.0) and 26.0 (14.9 to 37.0) kg, respectively). No significant increase in cardiorespiratory fitness was found (0.14 (-0.03 to 0.31) l/min). Conclusion: While conclusions on the safety of HIIT cannot be drawn, data from the present study do not support previous findings cautioning avoidance of HIIT due to a possible added risk of thromboembolic events in men receiving platinum-based chemotherapy for testicular cancer. Considering the potential for positive effects on cardiovascular outcomes associated with HIIT, future studies with robust design should be performed in this population to confirm these observations.