The Keto Diet and Baseball
By John Ivy, Ph. D
The Society has received inquiries from PBSCCS members concerning the effects of the Keto Diet on baseball performance. In an attempt to provide insight into this topic, the Website Education Manager approached John Ivy, Ph. D. for his take on the subject.
Here is what I know about the keto diet. There is no information or investigations on the effects of a keto diet on sports like baseball. In reviewing the literature, there are no findings that support a keto diet to improve athletic performance. Players that want to switch to this diet will find they will lose strength and feel tired for a couple of weeks before their bodies adjust to it. A keto diet does not make one stronger or give them more endurance. It will help someone lose weight and improve insulin sensitivity. In some cases, cholesterol levels are lowered, probably due to weight loss. I believe the keto diet is a good diet for overweight individuals who want to lose weight and improve their insulin sensitivity or have other metabolic problems (gets them off of junk food). Athletes that want to drop a few pounds of fat and look cut can use this diet for a few months to accomplish this, but I would not recommend it during the season or around major competitions.
The metabolic changes that can occur on a keto diet are an increase in the ability to use fat as a substrate, but a decline in muscle glycogen storage and an inability to use muscle glycogen as a fuel source during high intensity exercise. This will reduce one’s ability to sprint for a sustained period of time. For a marathoner or road cyclist, it would mean they would not be able to sprint to the finish. For a baseball player, going from first to third might be slower.
As I said before, there are no studies I am aware of that show a keto diet improves any type of athletic performance. This being said, I have not investigated this in the last 2 years.
Dr. John Ivy is the Teresa Lozano Long Endowed Chair Emeritus at the University of Texas at Austin. He received his Ph.D. in Exercise Physiology from the University of Maryland, and trained in physiology and metabolism at Washington University School of Medicine as an NIH Post-Doctoral Fellow. He served on the faculty at the University of Texas for 31 years and as Chair of the Department of Kinesiology and Health Education for 13 years. He is the author of over 170 scientific papers, numerous book chapters and four books on sports nutrition including the very popular Nutrient Timing. His research has pioneered our understanding of muscle metabolism and how nutritional supplementation can improve exercise performance, recovery and training adaptation. His research has also focused on the effects of exercise and nutrition on muscle glucose transport and insulin resistance, and how appropriate levels of physical activity and diet can prevent type 2 diabetes and other metabolic diseases.