I am in the habit of going for ultra runs (+42k) by myself, taking some supplies with me and refuelling along the way. The idea comes from Dean Karnazes, and what I like the most about it is the spirit of adventure involved in picking a spot in the map and then running towards it.

If you ever try any of this madness, here’s what has worked for me (I live in the Netherlands, so YMMV).

• Make few stops for refueling and plan them. Only change the plan if the situation really requires it. Not having to look for the next refueling stop eliminates a lot of thinking and doubting. A refueling stop every 30-40k is enough.
• Before going into the supermarket, think about what you want. You have plenty of time to think about that while you run. If you go in without a clear idea, and tired, you’re going to end up ambling by the aisles in a daze.
• Carry hydration and food with you. Eat and drink along the way. I use a 3L bladder and aim to drink it fully every 30-40k. This does mean you’re carrying 3-4k of supplies with you just after the stop (3L of fluid plus half a kilo of food). I see this also as an advantage if you later run an organized ultra, because then you compete without those kilos in your back.
• Sport drinks are a good idea, simply because of the electrolytes. Just having water and salty food ends up giving me a light headache and dizziness that I think is just an electrolyte imbalance.
• I find both sugar and fat are necessary. Ultra runs are one of the rare occasions in which food becomes a responsibility rather than a desire. My preferred combination is salty nuts (cashews, almonds, pistachios but not peanuts, since I find them slightly allergenic) and chocolate. Protein drinks are great too.
• Use comfortable, loose clothes, with reliable pockets.
• When navigating with Google Maps, use the bike mode. Bike paths are usually quite direct and sometimes safer than the paths suggested for walkers.
• Stretch every 30-40k; the main difficulty doing this is finding the place to do so. In my experience, stretching doesn’t get rid of the tiredness, but it drastically lowers the pain levels, therefore giving oxygen to your nervous system. This is very contrarian advice, most of what I’ve read and seen outright discourages stretching during races.
• Alternating between walking and running is much better than doubting whether you will continue or you will give up. Better to stay in the fight.
• If it gets very hard, remember that you’re also looking for that. Don’t think about quitting just because you’re going too slow.

Happy trudging!