Purpose Few studies have investigated long-term effects of physical activity (PA) interventions. The goal of this study was to evaluate whether or not increased levels of moderate to vigorous physical activity (MVPA) were maintained by cancer survivors 1 year after receipt of two home-based interventions. Methods The FRESH START trial randomized 543 breast and prostate cancer survivors to 1-of-2 mailed print diet and exercise interventions: sequentially-tailored vs. standardized (attention control). Each arm received eight mailings over a 1-year period, with follow-up at 1 and 2 years. This analysis focuses solely on the 400 participants who had suboptimal levels of MVPA at baseline (measured by the 7-Day Physical Activity Recall) and who completed the 2-year study. Results Median minutes of MVPA at baseline, 1-year and 2- year follow-up in the tailored intervention arm were as follows: 0, 90, and 60 min/week, respectively. The corresponding values in the attention control group were 0, 30, and 30 min/week. Significant improvements in MVPA from baseline to 2-year follow-up were observed in both study arms (p<0.01). While significant between-arm differences were observed at 1-year follow-up (p<0.01), there was only the suggestion of a trend (p00.08) at 2-year follow-up. Conclusions This study provides evidence that mailed-print exercise interventions result in significant and sustainable improvements in MVPA among newly diagnosed cancer survivors that are observed well after the intervention is complete. While tailored interventions, as compared to standardized materials, appear to produce superior improvements in MVPA initially, these differences diminish over time. © 2011 Springer-Verlag .