Acute effects of outdoor and indoor walking on cigarette cravings, withdrawal symptoms and affective response during temporary smoking abstinence.

RATIONALE: Cigarette smoking is one of the leading preventable causes of premature death worldwide. There is evidence in the literature that brief exercise units indoors can improve well-being in temporarily abstinent smokers and reduce cigarette cravings and withdrawal symptoms. OBJECTIVE: Because exercise in natural environments showed enhanced psychological effects, the aim of our study was to examine the acute effects of outdoor exercise compared with indoor exercise on craving, withdrawal symptoms and affective response in temporarily abstinent smokers. METHODS: In a randomized controlled within-subject-design, temporarily abstinent smokers (N = 16) participated in three interventions lasting 10 min: outdoor walking (OUT-EX), indoor walking (IN-EX) and a sedentary control condition (CC). Self-reported cigarette craving, withdrawal symptoms and affective response were assessed pre-, mid-, post-interventions and at follow-up. RESULTS: In contrast to CC, OUT-EX and IN-EX significantly reduced cigarette cravings during and at the end of the intervention compared to pre-intervention, but not at 20 min follow-up. Cigarette withdrawal symptoms decreased significantly over time in all three groups, but no significant group differences were found. OUT-EX and IN-EX, but not CC, showed significantly improved affective valence at the end of the intervention and at follow-ups. Outdoor walking resulted in significantly lower cigarette cravings than indoor walking at the end of the intervention. CONCLUSION: The study adds to existing evidence that short bouts of indoor or outdoor exercise can help reduce cigarette cravings and increase well-being in abstinent smokers. Further studies are needed to address the potential additional effect of outdoor exercise on craving, affective states and smoking cessation.

Is the cross-over effect of a unilateral high-intensity leg extension influenced by the sex of the participants?

BACKGROUND: While performing a unilateral muscle contraction, electrical muscle activity also arises in the contralateral homologous muscle, muscle group, or limb. When the muscle contraction induces muscle fatigue, females show not only a greater resistance than males but also a reduced contralateral muscle activation. The study aimed at investigating whether, during a high-intensity 30-s unilateral maximal effort isometric leg extension exercise, the contralateral non-exercising limb (NEL) knee extensor muscle activation would differ between females and males. METHODS: Twenty participants, 11 females (23.80 ± 2.15 years old) and 9 males (26.50 ± 2.45 years old), performed a unilateral 30-s exercise while surface electromyography (sEMG) was measured from the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) on both limbs. The maximal voluntary contraction (MVC) was measured for both the exercising limb (EL) and the NEL before (MVC PRE) and after (MVC POST) the 30-s exercise to assess muscle fatigue. RESULTS: While both females and males exhibited muscle fatigue in the EL (p = 0.015), females exhibited a lower MVC reduction than males (p = 0.042), suggesting that females were less fatigued than males. Although no muscle fatigue, i.e., no MVC force reduction was found in the NEL for either group before and after the 30-s exercise, the muscle activity of the VL was found to be of greater magnitude during the MVC POST only for females (p = 0.047) while it remained unchanged for males. During the 30-s exercise, the force output of the EL decreased only for males (p = 0.029) while females showed a preservation of the force output (p > 0.05). The sEMG activity of the NEL during the 30-s unilateral exercise increased for both groups in all measured muscles (all p-values < 0.03). CONCLUSIONS: Likely, different underlying muscle fatigue mechanisms occurred in the EL between females and males. Yet, our findings suggest that the cross-over effect to the NEL during the 30-s exercise occurred in a similar fashion in both groups. The current study suggests that the contralateral muscle activation seen with a unilateral exercise is independent of the sex of individuals. Therefore, unilateral training or rehabilitation-based protocols would similarly impact females and males.