Exercise outside of padel.

As a 53 year old let me tell you that you can never do enough hip flexor stretches. Squatting for lobs and burst movements are killing me and I limp for a few hours after a game.

Weights at home or even better a kettlebell or two of different weights helped me with strength training and preventing injury, plus lots of stretching and walking the dog to help recover the day after playing

It's not complicated, it's not exciting and it's been proven for decades: basic strength and bodybuilding training will be by far the best general physical preparation you can do for performance and injury prevention. I don't care if you think it's boring, lifting weights with decent intensity for a couple of hours per week will absolutely be the best bang for your buck. Eat your greens.

Kettlebells, dynamic stretches and intervals. Hands Down.

I feel you on the gym. I can't stand the toxic atmosphere of most gyms. But I ended up finding a small neighbourhood gym and it's a lot better - people feel more "normal" and less douchey and obnoxious lol. So if you can find something like that, it might be an option? Because as much as I don't like the atmosphere of gyms, the machines are soooo nice to work with! I personally mix padel with yoga (I do vinyasa for stretching and flexibility, and 4beat or rocket for strength and cardio), gym once a week for machines, and I also walk a lot and do a small bit of running, though I don't think the last part will be helpful for you :) And if you already do pilates, yoga may not be necessary - I've never done pilates, but from what I understand, they're fairly similar!

Besides that exercise is good and well worth it. This does sound like a technique issue. Using just muscle and power with very poor technique leading to injury. And probably lack of warmup as well.

Mobility training is #1. Stretch your body every single day. No excuses. You can find 20-30 minutes a day to do dynamic stretching, pullups, pushups, lunges, and squats. Add weight, but total weight isn't the goal. Kettlebells like others have said are fantastic. Just start very light. Learn the compound movements. If you're consistent over the course of several months, your pain will be far less after Padel.

Invest in a few kettlebells. It’s strength training but more functional than conventional weight training

I do gym, running, padel and volleyball. Doesnt matter. I always have to be careful how much I use my rotator cuff. I have quite a muscular build so I imagine that does not help at all. In the sense that its easier to hurt yourself if you use too much power. Recently did an MRI of the shoulder just to understand what is going on and apparently its healthy, but there is some wiggle room where my long biceps muscle attaches to the shoulder bone, so unless I take care of it properly (rigorous stretching and careful usage) I can expect the pain to be back. Surgery is an option but I’m fine not doing kicksmashes at all 😂. Using more viboras to attack, for my level this works just fine.

If you’re having rotator cuff injuries this can be addressed at home. There are 4 muscles that make up the rotator cuff and they are all small muscles that stabilise the joint, they don’t do the actual heavy lifting/generate much power. If you go on YouTube there are a million physio videos that will show you how to do this. They can all be achieved using a £10 set of resistance bands from Amazon. For general fitness ideally a strength and conditioning coach would write you a program. This could include dumbbells/kettlebells/resistance bands/bodyweight exercisss that could all be done at home with minimal equipment. If you can’t afford/don’t want to pay a coach/trainer, YouTube has a near infinite amount of resources and ChatGPT/Claude will write a decent program if you give I the right prompts. You’ll need to accurately describe any injuries and weaknesses, you’ll also need to give it parameters etc. All in all an S&C coach would be best but if you can’t there is loads of free stuff you can lean on.

Pilates plus some short HIIT-style sessions could work well, just keep the HIIT lower body and core focused (sprints, bike, jump variations) so you're not loading the shoulder on what's supposed to be a recovery day.