Short-term high-intensity interval training improves fitness before surgery: A randomized clinical trial

Improving cardiopulmonary reserve, or peak oxygen consumption( $$ O_2peak ), may reduce postoperative complications; however, this may be difficult to achieve between diagnosis and surgery. Our primary aim was to assess the efficacy of an approximate 14-session, preoperative high-intensity interval training(HIIT) program to increase $$ O_2peak by a clinically relevant 2 ml·kg^-1 ·min^-1 . Our secondary aim was to document clinical outcomes.

In this prospective study, participants aged 45-85 undergoing major abdominal surgery were randomized to standard care or 14 sessions of HIIT over 4 weeks. HIIT sessions involved approximately 30 min of stationary cycling. Interval training alternated 1 min of high (with the goal of reaching 90% max heart rate at least once during the session) and low/moderate-intensity cycling. Cardiopulmonary exercise testing(CPET) measured the change in $$ O_2peak from baseline to surgery. Clinical outcomes included postoperative complications, length of stay(LOS), and Short Form 36 quality of life questionnaire(SF-36).

Of 63 participants, 46 completed both CPETs and 50 completed clinical follow-up. There was a significant improvement in the HIIT group's mean ± SD $$ O_2peak (HIIT 2.87 ± 1.94 ml·kg¹ ·min^-1 vs standard care 0.15 ± 1.93, with an overall difference of 2.73 ml·kg¹ ·min^-1 95%CI [1.53, 3.93] p < 0.001). There were no statistically significant differences between groups for clinical outcomes, although the observed differences consistently favored the exercise group. This was most notable for total number of complications (0.64 v 1.16 per patient, p = 0.07), SF-36 physical component score (p = 0.06), and LOS (mean 5.5 v 7.4 days, p = 0.07).

There was a significant improvement in $$ O_2peak with a four-week preoperative HIIT program. Further appropriately powered work is required to explore the impact of preoperative HIIT on postoperative clinical outcomes.