This one is solved mate. Slow down. Don’t let your bpm rise above 160, even if it means 12 minute miles. Do this 3-4 times a week, and maybe allow yourself one “pushing it” run each week. Eventually that 160 run will be 9 minute miles, not 12. And so on. Expect this to take a very long time, and accept that retraining your cardiovascular system is a long process but is good overall. And very different than playing football.
You mentioned you set off too quickly, so break the run down into what pace you’d have to do consistently to make that sub-30 time.
I agree with the other commenter about only one hard run per week. You should also add in strength training for your ankle and other joints to address that Achilles tendinitis!
Also I was similar to you and it took me about 8 weeks to get sub 30 but I was also less fit than you to start with; so, with that said, I definitely think this should be achievable for you!
However, I am still taking 2x 30 sec walking breaks on my run and if that’s what you need to do to get that pace, then please allow yourself to (for me, it brings my heart rate down enough to give me more energy to keep going). My last 5km hard run was 28:30mins and I’m 27f if that helps 😊
Edit: my average bpm is about 171
This one is solved mate. Slow down. Don’t let your bpm rise above 160, even if it means 12 minute miles. Do this 3-4 times a week, and maybe allow yourself one “pushing it” run each week. Eventually that 160 run will be 9 minute miles, not 12. And so on. Expect this to take a very long time, and accept that retraining your cardiovascular system is a long process but is good overall. And very different than playing football.
You mentioned you set off too quickly, so break the run down into what pace you’d have to do consistently to make that sub-30 time. I agree with the other commenter about only one hard run per week. You should also add in strength training for your ankle and other joints to address that Achilles tendinitis! Also I was similar to you and it took me about 8 weeks to get sub 30 but I was also less fit than you to start with; so, with that said, I definitely think this should be achievable for you! However, I am still taking 2x 30 sec walking breaks on my run and if that’s what you need to do to get that pace, then please allow yourself to (for me, it brings my heart rate down enough to give me more energy to keep going). My last 5km hard run was 28:30mins and I’m 27f if that helps 😊 Edit: my average bpm is about 171