Researchers have contended that patterns of age-related decline are not necessarily due to age, but rather to disuse, or declining practice (Bortz, 1982; Ericsson, 2000; Maharam, Bauman, Kalman, Skolnik, & Perle, 1999). A regression approach was used to examine age and training variables as predictors of 10-km running performance between 40 and 59 years of age. A sample of 30 Masters runners (
Mage = 50.1 years, M10-km time = 39:19) reported data for ongoing training, cumulative running in the past 5 years, and cumulative running earlier in a career. In Analysis 1, ongoingtraining variables explained more variance in performance than age alone, and reduced the unique variance attributable to age in a combined model. In Analysis 2, findings were replicated using pastcumulative running variables and age; running in the past 5 years explained more unique variance than age alone. Discussion focuses on how findings relate to the selective maintenance account (Krampe & Ericsson, 1996), how various aspects of training help to preserve performance in aging populations, and recommendations for future research.