The effects of smokeless tobacco administration on perception of effort and cognitive task in men

A proliferation of nicotine use in the sport environment has been observed in recent years. Thus, nicotine has been placed on World Anti-doping Agency’s (WADA) 2013 Monitoring Program. The main objective of the present thesis was to study the effects of snus administration in men during sport and cognitive performances. To achieve this goal we designed four studies. First of all we aimed two surveys (STUDY I) to explicate snus past experience and current use (Survey I) and reinforcement effects of snus (Survey II) in a sample of winter sport athletes in northern of Italy. Eighty out of a hundred-eight participants (74%) tried snus at least once. Fifty-four participants were current snus users (50% out of the total). Forty-one participants were current smokers (38%). Smoking status and reinforcement effects of snus use (Survey II) information were also collected with the modified Cigarette Evaluation Questionnaire (mCEQ). Comparison between occasional vs. regular snus users (61 subjects) showed a statistically significant difference (p<0.05) for satisfying, calm and enjoying mCEQ items. Survey II confirmed that snus use is reinforcing in current snus users. In this STUDY I we hypothesize that both a successful ‘sport’ role–model, and the availability of accepted and flexible nicotine ‘multi-delivery’ may be the determinant factors of this phenomenon. The aim of the second study (STUDY II) was to firstly investigate the effects of snus on the perception of fatigue during an endurance exercise in men. The study was a double-blind placebo controlled crossover design study. We recruited 14 male non-smokers and non-snus users. Subjects were studied during three sessions on cycle-ergometer: experiment 1 (EXP1) consisted on an incremental exercise test to determine Wmax (maximal aerobic power output); EXP2 and EXP3 consisted on snus or placebo administration followed by an exercise at 65% Wmax until exhaustion. During the EXP2 and EXP3 the global rating of perceived exertion (RPE) was recorded, using the 15-point Borg scale. Before and after all experiments, subjects were administered the Profile of Mood of State questionnaire (POMS) and tested by means of Transcranial Magnetic Stimulation (TMS) to assess changes in cortico-motor excitability due to the prolonged exercise. In this STUDY II we observed that snus does not change RPE compared to placebo condition; this means that the sought effect could not be an improvement of fatigue during an endurance exercise until exhaustion. In the third study (STUDY III) our aim was to measure the effect of snus administration on the Iowa Gambling Task (IGT) an experimental test to study decision-making process. We recruited 40 male non-smokers and non-snus users. Subjects were randomized to blindly receive snus or placebo on two different days according to a cross-over design. No significant differences were observed in all results during the IGT performance under both conditions (snus vs. placebo). In the last study (STUDY IV) we assessed the effect of Snus on physical performance, heart rate variability, subjective arousal, and mental workload in non-smokers non-snus user amateur football players. Participants were administered either snus or placebo forty minutes prior to a fitness test battery. Hearth rate values, global ratings of perceived exertion, perceived arousal and, perceived mental workload were collected after the snus or placebo administration. The fitness test battery consisted of 4 tests: Handgrip Test, Counter-movement Jump, Agility test and Yo-yo intermittent recovery test. Significant differences were observed in agility test performance (18.82 ± 0.81 vs. 18.47 ± 0.62 seconds), level of mental fatigue before the experimental session (4.17 ± 2.38 vs. 2.94 ± 1.89 points), and perceived mental load after the overall experimental session (6.37 ± 2.16 vs. 5.44 ± 1.83 points) (snus vs. placebo conditions, respectively). The outcome of the STUDY IV suggested that snus, due to its detrimental effects on performance, is counter-indicated as an ergogenic aid. The current series of studies aimed to investigate the effects of snus administration on endurance performance, cognitive performance and football players’ performance showed that snus administration (vs. placebo condition) under our experimental conditions in non-smokers non-snus users healthy male subjects, did not improve sport and cognitive performance. Further researches are needed to investigate the effects of nicotine by snus on smoker athletes and/or snus users, during exercise and cognitive performance under satiety and abstinence conditions.