( ( Improvements ( in ( ( ( ( ( ( ( ( ( ( cardiovascular functioning ) , ) ( lipid profile ) ) , ) ( sleep apnea ) ) , ) ( physical activity ) ) , ) and ) ( work abilities ) ) ) ) ( ( have ( been reported ) ) . ) )
(ROOT (S (NP (NP (NNP Improvements)) (PP (IN in) (NP (NP (JJ cardiovascular) (NN functioning)) (, ,) (NP (NN lipid) (NN profile)) (, ,) (NP (NN sleep) (NN apnea)) (, ,) (NP (JJ physical) (NN activity)) (, ,) (CC and) (NP (NN work) (NNS abilities))))) (VP (VBP have) (VP (VBN been) (VP (VBN reported)))) (. .)))
Improvements in cardiovascular functioning, lipid profile, sleep apnea, physical activity, and work abilities have been reported.
(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.