3.3. Is the Stroke with a Straight or Bent Arm?

You may have already noticed that when I’m stroking, I don’t rotate with straight arms, but I bend my arms at the elbows both underwater and above water. We’ll explain both approaches.
We can look at the underwater stroke from two angles – we deal with the depth of the stroke and we deal with the curve of the stroke – whether it’s straight or zigzagged.
What do you think, is it better to stroke deeper or closer to the body? Both have their pros and cons. A deeper stroke is more efficient, you have a chance to push against more stable water when you reach deeper, you engage a larger part of your arm – from fingers to shoulder – and thus you move with greater leverage, pushing yourself a longer distance with each stroke. HOWEVER, it’s much more demanding and requires greater strength. Sprinters and those of you who are more muscular can take advantage of this, but for longer distances, a deep stroke is rather unsuitable, because it will build up lactic acid and burn out your shoulders.
On the other hand, a shallow stroke doesn’t require as much strength. This is because as we swim and break the surface with our hands, head and body, we create lots of bubbles and swirls around the body. We cannot effectively push against bubbles and swirls, it’s like swinging through air, it’s easier. All this comes at the expense of stroke quality, but benefits endurance performance, as it won’t burn your shoulders alive.
Imagine doing bicep curls with dumbbells for an hour. Can you lift three kilos for an hour? And can you lift five kilos for an hour? Those who work out know that every extra gram is a killer.
So the depth of your stroke is very individual and depends on your shoulder strength and the length of the front crawl section ahead of you. Of course, if you’re already swimming front crawl and looking for an impulse to speed up, maybe this information alone will be enough – reaching a few centimeters deeper – and you’ll immediately feel more pull.
And one more note about the deep stroke – even when we stroke deeply, the arm is never completely straightened and extended, it’s always slightly bent. With a deep stroke, it can be at about 120° at chest level, and with a shallow stroke, it bends toward the chest up to 60°.