Older individuals who have survived cancer and the commensurate treatment often experience a reduced quality of life in part due to their impaired muscular abilities and deficits in mobility. The purpose of this preliminary study was to determine the feasibility and preliminary efficacy of resistance exercise via negative, eccentrically induced work (RENEW) with older cancer survivors.
Older cancer survivors with a perception of moderate muscle weakness and fatigue participated in 12 weeks of RENEW. Measures of feasibility included (1) the participant's ability to progress the total amount of work of RENEW; (2) whether peak knee extension torque production became impaired; and (3) whether RENEW induced leg muscle pain as measured on a visual analog scale. The preliminary measure of efficacy included the performance of a timed up-and-go mobility test.
The participants significantly increased the total average work per week over the 12 weeks of RENEW. Participants increased (P < .001) their work approximately 3-fold from week 3 (7.6 [5.1] kJ) to week 12 (22.1 [14.8] kJ) without muscle pain over the 12-week RENEW training period. Knee extension peak torque production improved (11%) significantly (P = .02) (pretest: 248  N; posttest: 275  N) after 12 weeks of RENEW. The time to perform the up-and-go test improved (14%) significantly (P < .001) (pretest: 8.4 [2.7]; posttest: 7.2 [2.3] s) after 12 weeks of RENEW, suggesting preliminary efficacy.
Collectively, RENEW appears feasible and potentially efficacious for older, weak, and fatigued cancer survivors.
The use of eccentric muscle exercise may be ideally suited for older cancer survivors due to its high force and low energetic-cost capabilities
1 Department of Physical Therapy, University of Utah, Salt Lake City.
2 Department of Exercise and Sport Science, University of Utah, Salt Lake City.
3 Department of Orthopaedics, University of Utah, Salt Lake City.
Address correspondence to: Paul C. LaStayo, PhD, PT, Department of Physical Therapy, University of Utah, 520 Wakara Way, Salt Lake City, UT 84108 (firstname.lastname@example.org).