( And ( ( most individuals ) ( ( ( will only ) ( want ( it ( to ( succeed ( if ( it ( ( ( ( ( ( ( decreases work ) , ) ( increases efficiency ) ) , ) ( decreases frustration ) ) or ) ( improves profits ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (CC And) (NP (JJS most) (NNS individuals)) (VP (MD will) (ADVP (RB only)) (VP (VB want) (S (NP (PRP it)) (VP (TO to) (VP (VB succeed) (SBAR (IN if) (S (NP (PRP it)) (VP (VP (VBZ decreases) (NP (NN work))) (, ,) (VP (VBZ increases) (NP (NN efficiency))) (, ,) (VP (VBZ decreases) (NP (NN frustration))) (CC or) (VP (VBZ improves) (NP (NNS profits))))))))))) (. .)))
And most individuals will only want it to succeed if it decreases work, increases efficiency, decreases frustration or improves profits.
(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.