The core seems to be the body's most misunderstood muscle group, so what is it and how do you actually strengthen it? Pilates and yoga expert Gail Abell explains all you need to know…   WANT MORE FROM GAIL? To hear today's full interview, where she shares her take on the rise of the pilates...search for Extra Healthy-ish wherever you get your pods. For more on Gail’s studios, Upstate, see @upstate_studios or here, or their merch range Upstate Sport here.    WANT MORE BODY + SOUL?  Online: Head to bodyandsoul.com.au for your daily digital dose of health and wellness. On social: Via Instagram at @bodyandsoul_au or Facebook. Or, TikTok here. Got an idea for an episode? DM host Felicity Harley on Instagram @felicityharley.  In print: Each Sunday, grab Body+Soul inside The Sunday Telegraph (NSW), the Sunday Herald Sun (Victoria), The Sunday Mail (Queensland), Sunday Mail (SA) and Sunday Tasmanian (Tasmania).  See omnystudio.com/listener for privacy information.