Inspired by the latest post from @EssopMerrick because we see the break down of either of these types of training. Stop the @Spotify #rumpshaker playlist and listen to these words of wisdom before you exercise today.
So whats the physical therapist tangent/train of thought here? Both High Intensity Interval/Intermittent Training (HIIT) and Low Intensity Training (LIT) can produce results. Results are Goals. So there's an idea and an end result but the planning to get there is important. You can just start a HIIT or LIT program if you've never lifted your arms let a lone a weight. You can't expect to turn your half a pizza pie habit into the the elite marathon runner, or even the 5K runner for that matter.
What you need is to plan out the road ahead. You can read, You do this by getting a trained professional to evaluate your faults, work on those weaknesses, improve those strengths, and prevent those injuries. Those injuries are not just pebbles in the road. They're Grand Canyons of obstacles when doing less has been your recent norm. Moral of the story. Seek a out a certified strength trainer, strength and conditioning coach, even your local <cough cough> physical therapist can give you a full body evaluation and tell you were some road blocks you can expect when beginning a training program.
As far as Physical (Physio) Therapist visits in the U.S. Physical Therapist within Direct Access states can see you without a prescription but laws vary from states to state. Find out your states laws here via this pdf: Direct Access Laws By State - APTA.org