Tighter Tummy and Thinner Thighs

As a Master swimmer I am made painfully aware, each time I compete, of the importance of a strong core, and by that I mean stomach strength. I come away from each competition vowing to do more leg work, lots of legs-only with the kickboard, and for fitness there is really nothing to beat it.
One of the major benefits is that it tones the thigh and abdominal muscles terrifically and it improves stamina tremendously. I'm sure we all remember seeing the coverage of fighters like Muhammad Ali in their pre–fight training, and the first thing they do each day is hit the road to work on those legs, because that is what strengthens the core. Now, fortunately, we can work on the same principle but without the stress and damage to the joints by working on those legs in the pool. I like to do my leg work without a kickboard because I find using a kickboard makes me tighten up across my shoulders and at the back of my neck, so I use a "palming" or "feathering" action with my hands to support my upper body especially when I need to breathe. However if you're just starting out, use the kickboard as it's a little easier and provides more support. As for how many laps, I feel it's important to stay within your comfort level, but to gradually increase your lap count as you progress and get stronger. There is no doubt that you will notice improvement and that's when you can move on to more.
Stomach strength is so vital to general well being and stamina, and certainly great opera singers, orators, actors and athletes project from, and draw upon, that core strength. Now apart from the benefits to the stomach muscles gained from legs-only swim work, there is also a terrific slenderizing effect on the thighs, because unlike weight work or road work which "pumps" the thigh muscles, swimming is an elongating process as one is working in a less resistant medium.
So slim those thighs, tighten that tummy and feel great with a legs-only workout.