From working at the gyms as a fitness instructor, I have the basic training of First Aid and CPR/AED through the American Red Cross.

I own kits I carry on my gym bag that are cpr barrier mask, and basic first aid. Kinda interesting to see what they select to put in both. I purchased mine independently thru the Red Cross. But, the training does show you how to make do with common items you might not think of vs traditional medical items.

I carry my cell phone. Which also is a smart phone with GPS. Plus, my bici pc is a Garmin w/GPS. Handy to know where the closest land mark is, or gas station that might have supplies etc. Besides call for help.

I used to carry supplies in my road bag. Now I don't. My crash on the road bike was a much needed trip to the ER. Thus, the cell phone covered that one.

I carry steri-strips in my mtb gear. That I've crashed and used before I got outta the woods.

Also, I have asthma. I carry my inhailer with me always. I own / wear a RoadID bracelet which also notes this medical condition. In the event I didn't have enough wind to speak it out for myself.