This Endurance Session is a pyramid session, which means that we start with a small distance, work our way up to a big distance and make our way back down. If you're nervous about swimming the biggest distance, this pyramid will help you build your confidence while building your way up.
If you're not nervous about making the biggest distance, use this session to check up on your efficiency by counting your strokes for the first 25 of each 100. The number you start with is your benchmark for the rest of the main set, try to stay at this same number or lower.
The magic number of strokes for a 25 Freestyle is 20 strokes or below, anything above shows there is some work to do on the efficiency of your stroke. You will have a little play with this in the pre-set with the 4 x 50 or 25 stroke count. To get your strokes down, focus on a streamlined body position and getting more forward movement out of each stroke.
The whole main set is done at a comfortable 70% effort, which will give you time to focus on technique and counting strokes. Enjoy your swim!