Yoga mat workout

Yes. Given how much tennis/pickleball and swimming you do, I would make a short mat routine that fills the gaps those sports leave rather than trying to duplicate them.

And I wouldn’t accept the theory “do what you hate because you need it most” literally. Sometimes you hate an exercise because it’s exposing a weakness—but sometimes you simply hate the exercise. The better rule is:

Do the movements your sports don’t give you, especially the ones you can do consistently.

Your best mat exercises

I’d put these in roughly this order:

Exercise

Why it complements tennis/pickleball/swimming

Push-ups

Swimming/racket sports don’t give you much pushing strength

Dead bug

Deep abdominal control without irritating your back

Glute bridge

Glutes/hip extension—very useful for racket sports

Side-lying leg raise

Hip abductors; important for lateral movement

Bird dog

Back/hip/shoulder coordination and trunk stability

Prone Y/W raises

Upper-back/scapular muscles that help balance all the forward arm activity

Heel raises

Calves/Achilles, important for tennis and pickleball

A little plank variation

Whole-body bracing, but not essential if you hate it

I particularly like this 10-minute version for you

Do 2 rounds:

1. 10 push-ups

2. 8 dead bugs per side

3. 12 glute bridges

4. 10 side-lying leg raises per side

5. 6 bird dogs per side, slow

6. 8–10 prone Y raises

7. 15–20 heel raises

Rest only as needed.

That’s enough to be meaningful without turning your home routine into another workout.

What about the plank?

I’d not force yourself to do a traditional plank.

The reason I wouldn’t throw it out completely is that racket sports require you to transfer force through your trunk while your arms and legs are doing different things. But dead bugs and bird dogs train that quality in a more tolerable way.

If you want a tiny dose of the thing you hate, try:

10–15 seconds plank × 2

That’s it. Don’t turn it into a contest.

In fact, I’d rather see you voluntarily do two 15-second planks three times a week for a year than prescribe 60-second planks that you dread and eventually abandon.

One thing I would add to your thinking

Your sports already give you a lot of:

legs + calves + cardiovascular work + rotation + reaching + pulling + repeated shoulder movement.

The neglected areas are more like:

pushing strength → glute/hip strength → lateral hip stability → trunk control → upper-back/scapular endurance.

So your instinct to do push-ups + dead bugs + leg lifts was actually quite good.

I’d modify it to:

Push-up + dead bug + bridge + side leg raise + bird dog + Y raise

That’s a remarkably efficient little “anti-tennis/swimming imbalance” routine.

And because you’re already getting substantial exercise from your sports, 10–15 minutes is probably more appropriate than trying to build another major workout around this.