Abstract: Background: Despite improvements in surgical neck dissection (ND) procedures, head and neck cancer survivors (HNCS) still endure acute and chronic side effects such as loss of muscular strength, limitations in physical functioning, and fatigue, that impact quality of life and limit return to work. Light-to-moderate intensity resistance training has been shown to improve some of these side effects. Heavy lifting strength training (HLST) has shown promise in further improving outcomes in some populations, but it is unknown if HLST is feasible and safe in HNCS. Purpose: The primary aim of the LIFTING trial was to examine the feasibility and safety of a HLST program in HNCS ≥1-year post surgical ND. Methods: This single arm feasibility study recruited 8 HNCS to a 12-week HLST program. The 12-week HLST program included 2 training days per week, with a 5 to 8-week progression period towards lifting loads of 80%-90% of 1 repetition maximum (1RM) for bench press, and a rating of perceived exertion (RPE) of 8 to 9 (out of 10) for the squat and deadlift. Accessory movements were also incorporated into the HLST program. The primary feasibility outcomes included the eligibility rate (with reasons for ineligibility), recruitment rate (with reasons for refusal), 1RM testing rate (with reasons for not completing the test), HLST program adherence (including attendance, dose modifications, and progression), and follow-up assessment rate (with reasons for drop out). The primary efficacy outcomes were upper and lower body strength changes from baseline to postintervention. Secondary efficacy outcomes were physical functioning, quality of life, fear of cancer recurrence, pain, anxiety, fatigue, stress, shoulder mobility, sleep, and motivation. Wilcoxon signed rank tests were used to compare the pre-post changes in efficacy outcomes. Results: From November 2020 to June 2021 (8 months), 8 participants were recruited to the LIFTING trial. Due to the COVID-19 pandemic, we were unable to track the eligibility rate or recruitment rate, or the associated reasons for not participating. All 8 participants (100%) who were recruited were able to perform the maximal strength tests, and all 8 successfully progressed to heavy loads (80-90% 1RM) at approximately 5-weeks. Median adherence to the 24 supervised HLST sessions was 90.6% (range: 17 (70.8%) to 24 (100%)). Weight lifted from baseline to postintervention increased for the squat/leg press (median change: +36 kg; 95% CI: +25 to +47; p=0.012), bench press (median change: +7 kg; 95% CI: +2 to +10; p=0.012), and deadlift (median change: +13 kg; 95% CI: +6 to +25; p=0.018). In addition, the total weight of the 3 strength exercises combined significantly increased from baseline to postintervention (median change: +55 kg; 95% CI: +40 to +72; p=0.012). Significant improvements were also reported in resting systolic blood pressure (median change: -10.0 mmHg; CI: -17 to -6; p=0.012), resting diastolic blood pressure (median change: -13 mmHg; 95% CI: -16 to -4; p=0.017), resting heart rate (median change: -6 bpm; 95% CI: -10 to -1; p=0.035), and the global health status/quality of life measure (median change: +8.3; 95% CI: 0 to +16.7, p=0.041). No significant changes were observed for physical functioning, fear of cancer recurrence, pain, anxiety, fatigue, stress, shoulder mobility, self-esteem, or sleep quality. Motivational and behavioural outcomes were high at baseline, and remained high postintervention. No adverse events occurred. Conclusions: Preliminary results of the LIFTING trial suggest that a HLST program may be feasible and safe for HNCS who are at least 1-year post-ND, and have evidence of recovery of spinal accessory nerve function. Given our recruitment strategy, the eligibility and recruitment rates could not be adequately tracked. HNCS who performed the HLST achieved significant improvements in muscular strength (squat, bench press, and deadlift), resting heart rate, resting blood pressure, and global health status/quality of life. Future research should consider additional recruitment strategies and compare HLST to light-to-moderate load strength training to determine if it is a better prescription for improving outcomes important to HNCS including return to work. If proven more effective, HLST could be incorporated into the clinical care of HNCS to optimize physical and psychosocial outcomes in this underserved patient population.