It's good to have banana before running but...
バナナカステラも「朝食」にはいいかも。
banana castella is good for "breakfast" on a race day。
ひめじ菓子博金賞受賞だって！
It won Gold medal at Himeji Sweet Expo.
「朝食」と書いたのは、走る直前だと血糖値が上がり過ぎてそれを抑えようとインシュリンが分泌され、逆に低糖症になる恐れが。「大福餅症候群」とも呼んだりするそうです。
The reason why I wrote "breakfast" because if you have those sweets right before a start, the blood sugar level goes up too high, insulin is produced to make it lower, and there is a risk of to become a low sugar syndrome instead. It's also called "daifuku rice cake* syndrome."
* a rice cake stuffed with red bean paste.