Acute effect of S nus on physical performance and perceived cognitive load on amateur footballers

Smokeless tobacco ( S nus) is a substance that contains nicotine, which has been placed on W orld A nti‐ D oping A gency's 2014 Monitoring Program. A proliferation of nicotine use in sport has been observed in recent years, but little is known regarding its effects, especially on football players' performance. Therefore, the aim of this study was to assess the effect of S nus on physical performance, heart rate variability, subjective activation, mental fatigue, and perceived readiness before a physical test in non‐smoker, non‐ S nus user, amateur football players. Participants were administered either S nus or placebo 40 min prior to a fitness test battery (handgrip test, countermovement jump, agility test, and Yo ‐ Yo intermittent recovery test). Results showed that S nus intake (compared with placebo) increased perceived mental fatigue level and mental load, and reduced perceived readiness level and heart rate variability. No significant differences between the two experimental conditions were found in either performance in the physical tests or perceived physical fatigue levels. In light of these results, S nus could not be considered an ergogenic substance. On the contrary, based on the extant evidence linking mental load and fatigue with physical performance, we argue that the observed negative effects on mental fatigue, perceived readiness, and heart rate variability should be considered.