( ( Although ( ( smoke-free environments ) ( ( have not ) ( reduced ( ( smoking prevalence ) ( in ( most studies ) ) ) ) ) ) ) ( , ( ( such environments ) ( ( have ( been ( shown ( ( ( to ( ( decrease ( daily ( tobacco consumption ) ) ) ( among smokers ) ) ) and ) ( to ( increase ( smoking cessation ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (SBAR (IN Although) (S (NP (JJ smoke-free) (NNS environments)) (VP (VBP have) (RB not) (VP (VBN reduced) (NP (NP (NN smoking) (NN prevalence)) (PP (IN in) (NP (JJS most) (NNS studies)))))))) (, ,) (NP (JJ such) (NNS environments)) (VP (VBP have) (VP (VBN been) (VP (VBN shown) (S (VP (VP (TO to) (VP (VB decrease) (NP (JJ daily) (NN tobacco) (NN consumption)) (PP (IN among) (NP (NNS smokers))))) (CC and) (VP (TO to) (VP (VB increase) (NP (NN smoking) (NN cessation))))))))) (. .)))
Although smoke-free environments have not reduced smoking prevalence in most studies, such environments have been shown to decrease daily tobacco consumption among smokers and to increase smoking cessation.
(ROOT (S (NP (NP (NN Smoking) (NN tobaccowould)) (ADJP (RBS most) (JJ likely))) (VP (VBP have) (NP (NP (DT a) (JJ negative) (NN impact)) (PP (IN on) (NP (NP (DT the) (NN ability)) (PP (IN of) (NP (DT an) (ADJP (JJ individual) (S (VP (TO to) (VP (VB succeed) (PP (IN at) (NP (JJ physical) (NNS activities))) (SBAR (IN because) (S (NP (PRP it)) (NP (PRP it)))))))) (NNP decreases) (NN stamina) (CC and) (JJ cardiovascular) (NN efficiency))))))) (. .)))
Smoking tobaccowould  most likely have a negative impact on the ability of an individual to succeed at physical activities because it it decreases stamina and cardiovascular efficiency.