<http://webisa.webdatacommons.org/44290275> <http://www.w3.org/ns/prov#wasQuotedFrom> <drbookspan.com> . <http://webisa.webdatacommons.org/44290275> <http://www.w3.org/ns/prov#value> "Certain pop fitness and PT exercises say to tighten or brace or draw in abdominal muscles, squeeze together shoulder blades or gluteal or other muscles." . <http://webisa.webdatacommons.org/prov/268828098> <http://www.w3.org/ns/prov#wasDerivedFrom> <http://webisa.webdatacommons.org/44290275> . <http://webisa.webdatacommons.org/44290275> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/prov#Entity> .