A hell of a lot, especially if you’re male:
Handgrip strength (HGS) is a noninvasive measure of physical health that is negatively correlated with disability, morbidity, and mortality rates in adults. Highly heritable, HGS is indicative of blood testosterone levels and levels of fat-free body mass. In this study, we investigated whether HGS was related to measures of body morphology [shoulder-to-hip ratio (SHR), waist-to-hip ratio, and second-digit-to-fourth-digit ratio (2D:4D)], aggressive behavior, and sexual history in 82 male and 61 female college students. Results showed that HGS was correlated with SHRs, aggressive behavior, age at first sexual intercourse, and promiscuity in males but not in females. HGS appears to be an honest signal for genetic quality in males.
Source: “Handgrip strength predicts sexual behavior, body morphology, and aggression in male college students” from “Evolution and Human Behavior”