This question is about Cycling
Yes, potatoes can be a good fuel source for cycling. Potatoes are a good source of carbohydrates (the preferred fuel source for working muscles), are easily digested, and offer similar performance improvements to sports gels [ 1 1
1]. Potatoes can be a viable, whole-food alternative to the ingestion of gels during training and competition, and can help top-off and replete carbohydrate stores pre- and post-workout [
1]. Potatoes are also a rich source of potassium and when consumed after a long ride, can help replenish potassium lost through sweat.
 Salvador, A.F., McKenna, C.F., Alamilla, R.A, et. al. (2019). Potato ingestion is as effective as carbohydrate gels to support prolonged cycling performance. Journal of Applied Physiology, 127(6), 1651-1659. https://doi.org/10.1152/japplphysiol.00567.2019