Here is an article from “Tri Newbies Online” website
Touch and Go Drill (aka. Catch-up Stroke)
The Touch-and-Go Swim Drill: Creates a “long” stroke by
forcing the swimmer to reach out in front during freestyle
Another bad habit swimmers often fall victim to is not reaching out far enough during the recovery portion of the freestyle stroke. Often times, the swimmer will take a shorter arm stroke with the hand entering the water along side the head or perhaps just in front of it. See figure 1. This results in short, choppy arm strokes as well as an increase in the number of strokes over a given distance. It also reduces the amount of water the swimmer will “grab” during the underwater pull-through. Which, again, directly affects the distance the swimmer will travel per stroke. The less water the swimmer grabs during the underwater pull-through, the shorter the distance the swimmer will travel. Looking at Figure 2, you will see the swimmer is reaching out farther, well beyond the head. By reaching out, the swimmer will grab more water during the underwater pull-though. The result being, a greater distance traveled per stroke, fewer strokes taken and less energy spent during the swim
Furthermore, A short, choppy stroke can also cause the swimmer to “fishtail” or waddle back forth when swimming. Because of the direction to which the hand is pointing when entering the water, the natural momentum will cause the upper body of the swimmer to also move in that direction. Combine that with the same motion of the opposite arm and the result is a swaying or “fishtail” motion.See Figure 3. Now compare that to the swimmer in Figure 4who is reaching well out in front of the head, body straight and swimming straight. You can see why a long, reaching arm stroke yields a more efficient stroke.
What the “thumb-to-thigh” drill does for the underwater pull-through of the freestyle stroke, the Touch and Go drill will do for the recovery or out-of-water portion of the freestyle stroke. The Touch and Go drill was designed to teach the swimmer to reach out in front of him/her during the freestyle stroke and take advantage of the arm length. As previously explained, by reaching out far enough, the swimmer increases the amount of water he/she will “grab” during the underwater pull-through. This in turn, will help increase distance per stroke resulting in fewer strokes taken over a given distance.
The Drill: NOTE: This drill does rely on your kicking as well. So feel free to wear fins until you feel comfortable with the technique. To begin, push off the wall, both arms extended in front of you. With either arm, begin a freestyle stroke while keep the opposite arm extended out in front of you. Complete the freestyle stroke with the initial arm and touch the extended arm out in front at the end of the recovery portion. See Figure 5 below. This example begins as the swimmer is completing the underwater pull-through preparing for the arm recovery. Remember, keep the opposite arm extended until the recovery arm touches the hand out in front. Then complete the drill with the opposite arm. So basically you are swimming freestyle with each arm touching the opposite one out in front after recovery. In all fairness, this drill will probably seem confusing at first. But after a few tries, it will get easier. And breath to which ever side is comfortable.
Drill Set: 10 x 25’s Touch and Go drill. 15 seconds rest between each 25 yard swim. Adjust your rest accordingly.