Plantar fasciitis

I believe that being sedentary is what caused my PF. I had it pretty bad and am now pain-free. It takes a while to get over it, but here's everything I did:

1. See your doctor for a proper diagnosis.

2. STRETCH!

Every morning, before you get up, flex your foot up and at the same time press your fingers into the plantar fascia. You can feel it as a tight tendon running through the center of your arch. Massage it, press on it, and try to loosen it. Do this as much as possible. Your pain is due to this tendon being too tight. You can also roll your foot around on a tennis ball to do the same thing.

Gently stretch your hamstrings and calves often. You can also stand with your toes propped up on something and your heels on the ground. You should feel a good stretch of your achilles tendon. Best to stretch like this after you have been up and walking around for awhile. Do it twice a day.

Wiggle your toes and flex your feet a lot. PF happens when your feet don't flex often.

3. Get some shoe inserts. I started out with PowerStep (https://www.amazon.com/Powerstep-Length-Orthotic-Insoles-Original/dp/B011R81LBU/ref=zg_bs_3780081_3), which helped a bit. Then I got myself some Orthaheel shoes. They have high supportive arches and provided me with immediate relief. I wore nothing but Orthaheel sneakers or flip flops for about a year. They also have shoe inserts if you don't want to buy the shoes. I got my stuff from FootSmart. I believe that by simply walking around with shoes that pushed up on my arches is what cured me. Your results may vary.

As far as cardio exercise goes, you could use an exercise bike or rowing machine. Otherwise, using footwear with good arch support is your next best bet. Good luck!

All of the suggestions about stretching and massage above are very good--especially in the morning before you start walking. Use ice after massage or at the end of the day. 20 minutes. Also, don't walk barefooted ever. I've had PF on and off for several years. Bad Pf. Even had to use a cane for a while. What helped me over the hump was discovering that I am a pronator. A friend of mine in kinesiology suggested getting Asics running shoes. That helped a lot, but my PF got even better when I specifically started wearing the Asics Gel-Kayano. It is for moderate pronators. This shoe made all the difference. Find out if you are a pronator or supinator and get the appropriate shoe. But be aware that once you have PF it will take a good while to completely heal. I also wear good inserts in street shoes that correct for pronation. The only thing that should bend on the outsole of your shoe is the toe box. Everything else should be rigid. This is important for curing planter fasciitis and maintaining a healthy foot afterwards. Many people wear the wrong shoes that exacerbate planter fasciitis. I hope this helps. I feel your pain, literally.

Get Superfeet insoles and put a pair in each pair of your shoes. And, stretch, stretch, stretch the bottom of your feet. You can do that by getting into the position that yoga people call hero pose, except, instead of having the top of your feet on the ground, have the bottom side of your toes on the ground, with rest of the bottom of your feet facing the wall behind.
Here's a video that demonstrates: https://www.youtube.com/watch?v=MYKTf0RAJ38
Trust me, if you do these two things, and are diligent with the stretching, your PF will improve dramatically.
I have had PF for a number of years, because I played soccer on hard fields, run probably four times a week, and play tennis. These two things have done more than anything else for me, and mine is completely gone most of the time.
Good luck

I recommend a podiatrist who runs/works out so he will understand he needs to get you well and keep you moving. I swear by the night "boot"--that and insoles from the podiatrist have gotten me back to 95% pain free while continuing to run.