Weight lifting and Swimming

Greetings - I'm looking for some input. I am a 61 year old male who primarily swims freestyle and butterfly. My structured swim workouts are Tuesday, Thursday, and Friday evenings. I swim in meets occasionally, mostly sprints, and want to increase my competitiveness. Lifting weights is also a part of my workout regime. I have been advised to only exercise each muscle group once a week, but do so with extreme vigor, going to failure or near failure on my sets. I've got that currently split as follows, and with my swim workouts, my schedule looks like this: Saturday: Delts, Lats, Traps, Triceps, Forearms Monday: Pecs, Biceps, Glutes, and Quads Tuesday, Thursday, Friday: Swim My strategy is to work with weights on the most heavily used muscles for free and fly on Saturday, giving me three days rest before my swim workout. (Weight lifting interferes with my swimming if I try to do it the same day or even the day before). The Monday lifting workout is meant to focus on muscles less used in these strokes and therefore have less impact on the quality of my swim workout for the rest of the week. If you both swim and lift, I would value your observations on this strategy. Thanks.:)