For all those wondering about slendertone, just remember, if you used one for labour that is, what the TENS machine felt like. An electric current zaps the "motor-point" in your muscle, ie where the nerve that switches your muscle on and off is, with enough whack to get it to contract. This is what happened if any of you turned up your TNS machine too high. It is quite an uncomfortable sensation and completely involuntary. If you want any long term muscle toning to work, you've got to know how to switch your own muscles on and off yourself, not machine led all the time.
Sit ups aren't ideal as they cause the main rectus abdominis to contract. That's what most people refer to as the 6pack, (Brad Pitt has an excellent 6pack) without utilising the lower and oblique muscles. Besides, how often in life do you crunch up your tummy? Most people only use their rectus to lift heavy things, and if you don't have good background strength in your main supporting muscles, ie the lower abdos and obliques and back muscles, thats when you do yourself an injury. Hence for most women, post pregnancy, sit ups are out. Instead work on your postural muscles. Pilates is an excellent example of this.
Try this one basic exercise. Assume the "doggy" position on all fours. Try to keep your back straight, with your neck and head in line and right angles at your knees/hips and shoulders. Now let your tummy relax completely. It should really sag! Now take a gentle breath in, and as you breath out try to pull in your lower tummy and lift your pelvic floor muscles. (This is important as the pelvic floor and lower abdos interlink together, so contracting one gets overflow muscle tightening in the other). Hold the muscle contraction for a count of 10 whilst trying to breath normally. Repeat 10 times, slowly.
Now try to do the same exercise in different positions. Sitting, standing, walking etc.
Much better for you than a slendertone, you can do them anywhere once you recognise the muscles to use, and its free!!
For the motivational point of view though its still worth joining a class. Most gyms are cottoning on to Pilates and a lot of health/holistic clinics will run them.
Eventually you'll be holding these muscles in a semi-contracted state all the time, (as we should do naturally, sadly, but human beings are too lazy with their posture).
Sorry if I sound preachy, but as a physio, if I could encourage a few more people in the basics of good muscle use, there would be an awful lot less back pain around!
Another tip for all you pregnant people out there, you too can do this exercise up until the day of delivery. The beauty of this is a much faster recovery time for your tummy afterwards and theoretically an easier second stage of labour. Can't vouch for this myself as I had a caesarian 1st time around, (failed induction!) Still, I did have a flat stomach again just 3-4weeks post op, if you discount a bit of incision swelling, and even that was gone by 7weeks.
Oh dear, now I sound smug. Sorry!