Personalizing Nutrition for an Active Lifestyle

By Daniel Heller, MSc, CSCS, RSCC

In the summer 2018, while exploring the Sequoia National Forest in California on mountain bikes, my friends and I experienced “hitting a wall” or a sudden lack of energy, where we felt like we couldn’t go any further. The physical symptoms we shared were different, but most could be linked back to our diets: weakness, nausea, headaches, cramps, and dizziness. Avoiding, or eliminating, these unwanted symptoms all comes down to making the right choices before, during, and after embarking on physical activities.

Fine-tuning one’s diet assumes the current diet is already diverse and complete with a variety of color, different types of proteins (plant and/or animal based), carbohydrates from whole grains, vegetables and fruits, and healthy fats. Now one could ask the question: “Am I consuming the right amounts of the correct foods to meet the demands of my activity?” This type of nutrition- and activity-focused thinking is called “activity-specific nutrition.” It encompasses the type, duration, intensity, and environment of the physical activity about to be embarked upon. Each of the factors that make up activity-specific nutrition play a role in determining what kind of sustenance our bodies need to prepare, sustain, and recover from the activity we intend to undertake.

Carbohydrates and proteins are the primary macronutrients utilized in physical activities that can be categorized into endurance and resistance training. For endurance-based activities (cycling, hiking, and running), carbohydrates provide sustained energy.1 It should be noted that current research also suggests that fat can be used as an endurance fuel source.2 For resistance training (weight lifting, circuit training, and manual labor), protein is critical in helping to repair and rebuild muscle.3

In a previous article three principles of strength and conditioning were discussed in detail. Now, we add an additional piece: What are good food choices that will support your favorite activities?

Answers to commonly asked questions can provide insight into more effective ways to fuel your active lifestyle:

Question: What should I eat after I’m done lifting at the gym? I usually train my upper and lower body on separate days. My workouts last about 60-90 minutes. I want to get bigger and stay lean.

Answer: For this type of intense resistance training, it is recommended that intake of 15-25 grams of protein following your workout is best. Choose a protein supplement (powder or bar) or, preferably, eat a complete meal, such as an 8-ounce chicken breast, cup of brown rice, and a vegetable.

Question: I love hiking, and usually my hikes last from 3-6 hours and cover about 8-10 miles. I don’t like eating packaged energy foods (bars and gels). What do you suggest?

Answer: Hiking is a fantastic physical activity; the distance and duration described is endurance at a moderate intensity. If you don’t like packaged nutrition, I suggest you prepare food the night before. I have two main items I make: First is a peanut butter sandwich with fresh berries and honey instead of jam. Second is a trailside preparation of crackers, cheese, and a cured meat. When making your selection, choose the items that have the fewest number of ingredients on the labels. Carbohydrates with a moderate glycemic load will be ideal to help maintain energy throughout your hike.


If you’re somewhere in the middle and usually participate in a high-intensity, interval training type of workout, you’ll have to consume enough protein to rebuild muscle and muscle fibers that undergo microtrauma from resistance training and replenish glycogen stores (energy) depleted from aerobic physical exertion.

The reality of caloric expenditure is that it varies based on age, body composition, and physical activity intensity. Many sports watches provide estimated caloric expenditure in real time. This makes it simple to assess under- or overconsumption of food as a whole. The number of calories consumed, and what are burned, needs to be in accordance with physical activity goals. For example, if your goal is to lose weight, you should be at a caloric deficit (eating 200-500 calories below what you’ve burned according to what your watch says). Fitness devices vary in price and features, but basic functions of measuring number of steps walked, calories burned, and heart rate are now commonly available on most of these devices.

There are, of course, caveats to the basic ideas for activity-specific nutrition presented here. For example, if you’re adhering to a ketogenic-style diet, the carbohydrate suggestion will not work. For ketogenic diets and endurance performance, I suggest reading Dr. Silverman’s article on why the keto diet may benefit athletes.

Until next time, live well and live active.



  1. Jeukendrup A. A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise. Sports Med. 2014;44(1):25-33.
  2. Volek JS, Noakes T, Phinney SD. Rethinking fat as a fuel for endurance exercise. Euro Jl Sport Sci. 2015;15(1):13-20.
  3. Phillips SM. Defining Optimum Protein Intakes for Athletes. In: The Encyclopaedia of Sports Med. John Wiley & Sons Ltd; 2013:136-146.


Daniel Heller, MSc, CSCS, RSCC:

Holistic strength and conditioning coach, Daniel Heller, MSc, CSCS, RSCC earned his Bachelor’s of Science in exercise science and wellness from Bastyr University in 2009 on a direct path to having a positive impact in the world of exercise and sport science. Since graduating from Bastyr, Heller has gone onto coaching youth athletes in ice hockey, figure skating, and mountain biking. As well as developing postural alignment and compression garments with Oakley Inc. and was the primary author of the exercise chapter for the Metagenics FirstLine Therapy Patient Guidebook. In 2016, he received his Master’s of Science degree in Strength and Conditioning from the University of Edinburgh in Edinburgh, Scotland. Heller is continuing to coach and actively participates in the field of strength and conditioning.

Daniel Heller is a paid consultant and guest writer for Metagenics.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.