Perceived physical strength in men is attractive to women but may come at a cost to ejaculate quality

Studies of sexual selection acting on physical strength in humans have focused mostly on its role in premating male-male competition. Recent theoretical frameworks suggest that male strength could be subject to trade-offs with postmating sperm competitiveness. Here, we examined whether male strength is linked to ejaculate quality. We also asked whether strength is attractive to women and affects male self-reported mating success. Perceived strength was negatively associated with ejaculate quality as predicted by the trade-off hypothesis. Perceived strength positively predicted attractiveness and both perceived strength and attractiveness shared similar variance in predicting self-reported mating success. Our findings indicate that despite the benefits to premating sexual selection, having greater strength may come at a cost to sperm competitiveness.