Cliff McArthur

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Cliff McArthur of Phoenix, Arizona is a registered dietitian nutritionist (RDN) and certified specialist in sports dietetics (CSSD) with over 20 years of experience in nutrition counseling, education, and coaching. He works regularly with athletes of all types and ages, from high school to masters, 5K runners, mountaineers, tennis and pickleball players, to marathoners, triathletes, and ultra-endurance cyclists and some of the most elite and fit special operations forces of the United States military.

Cliff works to understand where you are in life and sport and meet you there. He provides practical nutrition solutions that are realistic for you. His guidance empowers you to realize optimal mental and physical performance. Cliff is more a nutrition coach than a nutrition instructor. The service he will provide you extends well beyond simply telling you what and when to eat; it includes motivating you to stick with the plan and holding you accountable for doing so.

Cliff holds a Master of Science in Applied Nutrition from Northeastern University in Boston and bachelor’s degrees in biology and biopsychology. He has completed extensive additional coursework in biomedical laboratory medicine, nutrition, and dietetics. Cliff keeps abreast of current developments in metabolism, nutritional biochemistry, and exercise physiology. His clients receive advice in all these areas as well as menus, meal planning, and supplementation.

Cliff’s approach to nutrition is further informed by his own 40 years of experience as an endurance runner and cyclist. He has lost count of the number of marathons he has run but is quick to note they have included the Chicago and Boston Marathons (his favorites) and several trail ultra-marathons as well as numerous half-marathons, 10Ks, and 5Ks. He’ll tell you he’s a better sinker than swimmer and sticks to land for sport, unless it’s scuba diving (which he also pursues with passion.) For many years he was a consistent sub-3:00 marathoner. While distance running was (and still is) his competitive passion, long-distance cycling has been his deeper love, his way to escape, challenge and compete against himself, and test his limits. “I love running, need running, must run. But cycling is more fun.” He has ridden several centuries as well as multi-day rides totaling 1000 miles. He is less young and slower now but continues to test himself against the century.

Better health supports better performance ­– Higher levels of athletic performance are possible only if an individual adopts appropriate nutrition practices. Stronger and more tactical nutrition practices improve health as well as energy, mental fortitude, work capacity, power output, sleep, and recovery.

Cliff’s clients benefit from his 40+ years as an endurance athlete and deep knowledge of nutrition science. He looks forward to helping you determine and adopt nutritional practices appropriate to your goals.

When he’s not coaching, Cliff can be found woodworking, hiking, camping, and doing road trips in his 1985 VW Vanagon.

Events: All Endurance Events

Services: Nutrition

Specialties: Nutrition

"If you are seeking customized and periodized guidance and support, Cliff McArthur is your coach! He is highly knowledgeable of human physiology and the impacts of sport on the body. He will dial in your nutrition intake to optimize and elevate your performance outcomes." ~CL

"Cliff absolutely made me a better athlete and performer in every sense of the word. Not only did he help me unlock more of my physical potential, he also helped me understand the mental and fueling side to performance. I would recommend Cliff to anyone looking to holistically improve their capabilities." ~Brian