Introduction: Swearing fulfils positive functions including benefitting pain relief and physical strength. Here we present two experiments assessing a possible psychological mechanism, increased state disinhibition, for the effect of swearing on physical strength. Method: Two repeated measures experiments were carried out with sample sizes N=56, and N=118. Both included measures of physical performance assessing, respectively, grip and arm strength, and both included the Balloon Analogue Risk Task (BART) to measure risky behaviour. Experiment 2, which was pre-registered, additionally assessed flow, emotion including humour, distraction including novelty, self-confidence and anxiety. Results: Experiments 1 and 2 found that repeating a swear word benefitted physical strength and increased risky behaviour, but risky behaviour did not mediate the strength effect. Experiment 2 found that repeating a swear word increased flow, positive emotion, humour and distraction and self-confidence. Humour mediated the effect of swearing on physical strength. Discussion: Consistent effects of swearing on physical strength indicate that this is a reliable effect. Swearing influenced several constructs related to state disinhibition including increased self-confidence. Humour appeared to mediate the effect of swearing on physical strength, consistent with a hot cognitions explanation of swearing-induced state disinhibition. However, as this mediation effect was part of an exploratory analysis, further pre-registered experimental research including validated measures of humour is required.