The main objective of this study was to test the differences among four techniques for the determination of lifting abilities. This study introduced a new submaximal isometric strength testing technique. The proposed test was based on the concept of acceptable maximum effort (AME) which is the level of static exertion the individual is willing to perform voluntarily and comfortably without over-exertion (as opposed to the maximum ability of performance). Twelve male and five female subjects underwent the protocol of the four strength testing techniques investigated: isometric maximum voluntary contraction (MVC); maximum acceptable weight (MAW); maximum dynamic lifting (MDL); and acceptable maximum effort (AME). The results showed that MAW recorded the lowest values followed by AME, then MDL, then MVC. The correlation between AME and MAW was higher than that found between MVC and MAW. Also, it was found that AME is a reproducible measure of muscular functional abilities. On the average, the coefficient of variation was less than 15% for data for both males and females. The implications of these results in determining lifting abilities are discussed.