Yes, a small amount of peanut butter can be part of a nutritious pre-run meal or snack when paired with a carbohydrate source (such as a banana or a piece of toast) 2 hours or more before exercise. Consuming protein and carbohydrates before endurance exercise has been shown to improve sports performance [ 1 2
1]. Eating carbohydrate and protein together pre-run may also help prevent hypoglycemia during a run and enhance fuel storage [
However, portion size and timing are important. Too much peanut butter consumed too close to a run may lead to GI distress and discomfort. Limit your portion of peanut butter to 2 tablespoons pre-run, and consume with 15-30g of carbohydrate at least 90 minutes before you lace up your sneakers.
 Kerksick, C. M., Arent, S., Schoenfeld, B. J., Stout, J. R., Campbell, B., Wilborn, C. D., Taylor, L., Kalman, D., Smith-Ryan, A. E., Kreider, R. B., Willoughby, D., Arciero, P. J., VanDusseldorp, T. A., Ormsbee, M. J., Wildman, R., Greenwood, M., Ziegenfuss, T. N., Aragon, A. A., & Antonio, J. (2017). International society of sports nutrition position stand: nutrient timing. Journal of the International Society of Sports Nutrition, 14, 33. https://doi.org/10.1186/s12970-017-0189-4
 Ormsbee, M., Bach, C., & Baur, D. (2014). Pre-Exercise Nutrition: The Role of Macronutrients, Modified Starches and Supplements on Metabolism and Endurance Performance. Nutrients, 6(5), 1782–1808. https://doi.org/10.3390/nu6051782