How can I keep my lower back relaxed while swimming

Question

I have been learning to swim (only freestyle) from last December 2016.
When I try to take a breath, my head is under water and I end up either drinking water or stop swimming.
My coach tells me there are two things which are wrong when I swim

1. Keeping the hand in cupped posture - bad form
2. Keeping the lower back tensed.

Through conscious practice I can overcome the first one, but for relaxing my lower back (hips), I do not know what to do.
Coach is telling me that, it is for this reason that my body does not stay afloat when in water.

Are there any specific drills or exercises that can help?

Answer 1

You should be swimming with a braced core (your core includes your lower back), so this is actually not a bad thing.

As for your issues with breathing properly:

1. Try using a swim snorkel. They are relatively cheap, and you can focus your arm stroke without having to turn to breathe.

2. Breathe every three strokes and to the side. Are you picking your head up to the front to breathe? Don't. You should be turning your face to the side, with your mouth breaking the surface of the water in order to inhale, without losing forward momentum.

3. Exhale slowly under the water. I find it helpful with beginners to exhale to a 3-count that matches the strokes they are taking. This way they aren't gasping for air. Your exhalation should be controlled.