It is entirely possible to do very well in a race just doing a good rigorous form of yoga. I remember when I went on a climb of katadhan and several other ranges, and all I did before doing them was do my yoga practice. The boys (DH and his best friend) were like "you're going to be SORE!" and all kinds of stuff. But I was fine -- no problems with my feet, my legs, no tiredness, it was easy. Enjoyed it.
I just liked the training. And if you like that, then you do that and no worries.
But all of my trainings were sprint-based. Meaning, instead of doing a long, slow swim in the pool, I did sprints of various distances with shortened rest periods in between. Instead of doing long rides, I mostly did hills (which functions like intervals). For running, I'd do an occasional long-slow (for my distance), but mostly focused on speed intervals.
It worked nicely. Kept training times down (i had a lot to do between law school, working part time, family life, commuting, etc) and created nice fitness.
Gotta do what works for you.
Best time to ensure your muscles are utilizing carbs is directly after a workout. Carbs are driven into the muscles rapidly when consumed at that time. This would be a good time for a banana or your dried fruit and a quick-digesting protein ( I use whey powder)
Sweet potatoes, taro root and cassava root are great primal carb sources too. I have athletes I coach who are doing Ironman triathlons and running crazy long distances and they all eat lots of sweet potatoes, We shoot for 150-180g/day of carbs on training days, 100g on off days. Many have added white rice back into the mix and have seen no real down side. Lara bars are a good packaged source of calories. You can keto-adapt to a point. For more on the subject you might try reading about Metabolic Efficiency. Bob Seebohar (US olympic tri team nutritionist) is an advocate of a high fat diet for athletes. Studies have show that the refeeding window is a bit of a misnomer, all the the benefits are only realized if you are doing another workout later in the day. If you can't refuel for a couple of hours its not that big of a deal. Short distance racing requires very high intensity, practice it.