'Tis true, 'tis true. If you were to use correct posture whenever you were standing or walking you would strengthen your abs more than performing sit-ups 'til you puked. It is a matter of very high repetition and low levels of work. I get comments all the time along the lines of: Of course, you have a flat stomach you do Pilates all day. Wrong. I don't do Pilates all day; I teach Pilates all day. Secondly, I haven't done a sit-up in over a decade: bad back. Lastly, my abs are very solid. I stand up straight as often as I remember (dancers are notorious for horrible posture) and when I exercise I try to keep my alignment.
Think about your own workout. You are in your Pilates class and working, working, working. You stand up to leave and your posture is horrendous. I see it everyday. What did we just work on for the last hour? We worked on making you feel better: with an awesome bonus result of having a higher tush and sexier arms. If you stand up and don't stand up straight you throw a lot of that work away. Yes, you'll retain a percentage of it but not all of it. Your arms and your butt will benefit but your abs won't be able to retain as quickly if you stand with the abs relaxed all day. But, really, it's not just the abs that work when you stand up straight. Here's the list:
When you stand up straight here are just a few muscle building benefit:
- Abdominals: Stand with the abdominals gently braced
- Upper Back: With your shoulders squared off (not yanked together) and gently pressed down the upper back gets a great workout as do the posterior deltoids (shoulders)and latissimus
- Gluteals: For those of you who stand with your hips swayed forward, the gluteals never work and the butt disappears and the hamstrings are tight enough to saw down a redwood with.
Most importantly when you stand up straight you are grooving a pattern, setting a new 'normal'. Ever watch Cesar Milan on the Dog Whisperer? His most common tip is to get your dog out for a walk and train your dog while walking. You are setting a pattern, so when you bring the dog home he is more family/house friendly. More in tune with what you need from him. Same with your body. Train it to be there for you. The benefits of standing up straight aren't purely an instantly flatter stomach and a sexier body. You create adequate space for your organs (poor posture crushes them) which leads to improved lung, heart and digestive function. Improved posture has even been said to improve mood. One of those reverse psychology tricks on your brain: act like you feel great and eventually your brain will believe it.
I could go on....