Run on a flat path, track or treadmill. You can use the 8/2 method of 8 minutes running, 2 minutes walking. RPE should be light - 5/6 out of 10.
Swim Drills Day. Today your only goal is to get in the water and count how many strokes it takes you to swim from one end of the pool to the other.
Focus on keeping your head down and turning, but not lifting your head to breathe. Take a rest of no more than 1 minutes between lengths. Try to swim continuously even if you have to swim side stroke, breast stroke, or on your back. Keep moving and complete 400 yards or 1/4 of a mile!
When you are done swimming, work on stretching your back, your arms, shoulders and neck muscles.