628 Journal of Strength and Conditioning Research, 2002, 16(4), 628–640  2002 National Strength & Conditioning Association Absolute Vs. Relative Machine Strength as Predictors of Function in Older Adults KATHLEEN M. KNUTZEN, 1 LORRAINE BRILLA, 1 DENNIS CAINE, 1 GORDON CHALMERS, 1 KATHY GUNTER, 1 AND PHILIP SCHOT 2 1 Department of Physical Education, Health, and Recreation, Western Washington University, Bellingham, Washington 98225; 2 Department of Exercise Science, Pacific University, Forest Grove, Oregon 97116 ABSTRACT This study examined the relationship between absolute and relative (1 repetition maximum/LBM) strength vs. 13 differ- ent functional measurements in 143 older adults (mean = 70.28, standard deviation = 7.90 years). Strength for 11 ma- chine lifts was determined using a predicted 1-repetition maximal strength measurement. Zero-order correlation re- sults between absolute and relative strength vs. function measures demonstrated very weak to moderate correlations in the range of 0.02–0.57 and 0.01–0.44, respectively, withthe lowest correlations present between strength and balance measures and the highest correlations present between strength and the carrying task (p  0.05). Stepwise multiple regression results also confirmed the low predictability of functional tasks using strength measures, with absolute and relative strength measures accounting for only 3–38% and 3– 33% of the various functional measures, respectively. This study identified specific strength measurements that contrib- ute to the variance in a functional task but also clearly in- dicated that strength alone cannot serve as a predictor of function in older adults. Key Words: elderly, weight training, mobility, ADL Reference Data: Knutzen, K.M., L. Brilla, D. Caine, G. Chalmers, K. Gunter, and P. Schot. Absolute vs. rela- tive machine strength as predictors of function in older adults. J. Strength Cond. Res. 16(4):628–640. 2002. Introduction S trength and speed of movement decrease from the fifth decade of life onward (44), and the decremen- tal loss may have some effect on concomitant imped- iments seen in functional tasks such as walking, chair stands, and other daily activities. The relationship of strength to activities of daily living (ADL) has been suggested in a variety of studies involving older adults (6, 10, 16, 26, 39, 40, 42, 59). Many of these studies have only examined a few strength measures such as the leg press or have only observed the strength and function relationship incidental to the purpose of the study. The strength and function relationship has been ex- plored from various points such as epidemiology stud- ies, which have supported the ‘‘dose-response’’ rela- tionship of declining muscle mass to functional limi- tations across the aging process (52). Intervention strength training studies have also reported significant gains in functional status (9, 23, 35), but the specific relationship between strength and function has not been clearly defined (12, 13). Recently, Ferucci et al. (24) suggested that the association between strength and function may be present only in the lower portion of the strength range, may be nonlinear, and may vary depending on the functional activity. For example, walking speed was linearly associated with knee ex- tensor strength for the entire range of strength, but chair stand times were associated with knee extensor and hip flexor strength only when the strength values were below 10 and 15 kg, respectively (24). Chandler and Hadley (13) also suggest that frail elderly persons have more to benefit from the strength training when it comes to improvement in gait speed and chair rise time. Strength, the maximum amount of force a muscle group can generate at a specific velocity (28), must be maintained at a minimal baseline level to generate enough force to control body and segment mass effec- tively. Because older adults lose strength they must use a greater percentage of their maximum strength to perform activities, and many older women, in par- ticular, may be at functionally important strength-re- lated thresholds (57). Although decreases in strength below a threshold level can lead to functional impair- ment, an increase in strength can have a very positive influence on function. In their study of 703 older wom- en, Davis et al. (21) reported that a 1 standard devia- tion (SD) increase in strength was associated with a 2– 4% increase in performance measures of walking speed, chair stands, functional reach, and hand reac-