Metabolic Flexibility as Nutritional Periodization - Aligning Your Diet and Exercise for Better Performance


Nutritional strategy is a hot topic in endurance sports these days with debate raging between whether a fat-centric or carb-centric diet is better. But maybe there is a middle ground. Maybe athletes can develop a nutritional strategy designed around fueling for the energy system they are going to use on a given day. This nutritional strategy is called metabolic flexibility.

In simple terms, Metabolic Flexibility is your body’s ability to switch between fat fueling and carb-fueling. It may not be a surprise to say that a healthy metabolism is flexible. For our purposes here, you can think about metabolism as functioning on a spectrum ranging from fat fueling on one end to carb fueling on the other end. As one consistently trends toward either extreme of the spectrum, their metabolism becomes relatively inflexible.

For example, someone who relies on a carbohydrate-rich diet becomes more insulin resistant which undermines their ability to consume fat and even carbohydrates (which leads to overeating and more weight gain). While this specific metabolic inflexibility is seen most prominently in obese people and type-2 diabetics, it is also common for seemingly healthy people to have a high degree of metabolic inflexibility.

Many endurance athletes, for example, can develop metabolic inflexibility and, eventually, insulin resistance from consistently eating carb-rich diets and fueling on high sugar supplements like gels and sugary electrolyte drinks. The insulin resistance can be masked by high levels of exercise which often helps to curb excess weight gain but, eventually, the symptoms of insulin resistance will manifest in other ways.

Why is flexibility important?

Most importantly, the more metabolically flexible you are, the easier it is for you to eat a diet that is balanced in macronutrients (fat, protein, and carbohydrates). The more balanced your macronutrient composition, the more likely you are to receive the necessary micronutrient (vitamins, minerals, and polyphenols) intake your body needs to thrive and recover from regular physical activity.

When you are metabolically flexible, you can eat the right things at the right time because you can utilize different fuel sources to power different energy systems (i.e. Aerobic = higher proportion fat and Anaerobic = higher proportion glycogen).

It also means you can optimize how you feel from day-to-day by eating in a way that aligns with your energy demands in order to improve sleep, curb hunger cravings, and stabilize your mood and energy levels throughout the day.

How does metabolic inflexibility develop?

Lifestyle is the most common factor. The most common trend in our society today is a sedentary lifestyle combined with the Standard American Diet - characterized by high consumption of processed and refined foods (mostly carbohydrates) and overeating. Both of these factors contribute to insulin resistance and, eventually, overweight and/or obesity and potentially type-2 diabetes.

Another important contributor is mitochondrial dysfunction and low mitochondria levels, both of which can often stem from a poor lifestyle. Too few and dysfunctional mitochondria make it more difficult for your body to produce and utilize energy, especially stored fat. Because your body can’t utilize all of your ingested or stored energy,  you experience an increased desire to eat even in the face of excess energy. This creates a negative feedback loop that is detrimental to your health.

How do you become more metabolically flexible?

  1. Diet

    • Eat Paleo + Portion Control

  2. Exercise

    • Specifically, more easy running + more weight training

  3. Recovery

    • Cold Stress

  4. Stress Management

    • Specifically, more easy running, but also less life stress


The Paleo nutrition template is an ideal template for ensuring your diet balances macronutrients and maximizes micronutrients. There are endless resources to help you understand and learn the Paleo Principles. A good starting place is to eliminate all processed and refined foods and sugars from your diet (except high-quality dark chocolate!). It’s okay to slip up from time-to-time but it is imperative you commit to the life change to succeed and sustain metabolic flexibility and; thereby, a healthier and happier version of yourself!

Portion control is your ticket to controlling energy excess which is a critical contributing factor in developing insulin resistance. If you’re worried about your inability to intuitively settle on reasonable portion control guidelines for yourself, you can test your metabolic rate (i.e. respiratory quotient) and then track your daily exercise and caloric intake for a couple of weeks to get a good sense of how to balance your caloric intake to avoid overeating. And keep in mind that caloric excess should be viewed in a window of about 3 days versus day-to-day. Some days, you may need to eat more and some days you may need to eat less. Be, well, flexible!


Exercise - aerobic activity and strength training - can help in two key ways. First, it improves insulin sensitivity which, in turn, helps to restore your fat burning capability. Second, exercise helps to both repair dysfunctional mitochondria and produce more mitochondria through mitochondrial biogensis.

For runners, both high-intensity interval sessions and long, slow aerobic sessions support mitochondrial biogenesis. For stress management purposes, it is important to strike a balance between intensity and easy aerobic/recovery running. This facilitates a variety of external stressors to produce differentiated adaptation and it helps to minimize stress on the central nervous system that accumulates from high-intensity exercise - specifically the sympathetic branch of the autonomic nervous system.


Aside from recovery running, cold Stress is the primary recovery modality that can aid mitochondrial biogenesis and, thereby, help improve your metabolic flexibility. Cold stress is optimal 30 minutes after exercise (specifically cold tubs). Less than 30 minutes undermines the pro-inflammatory effects that support exercise-induced physiological adaptations. After 30 minutes, you will still realize benefits for mitochondrial biogenesis. You can also incorporate cold showers.

Stress management

Cortisol is a catabolic hormone; especially, when regularly present in excess. It breaks down healthy muscle tissue which undermines gains in physiological adaptations from exercise. The answer: More recovery running and less life stress!

Running below your Maximum Aerobic Function (MAF) facilitates recovery and does not activate the sympathetic nervous system and corresponding stress hormone response. Mitigating stress in the rest of your life will also help prevent cortisol production (and other stress hormones).

How to use metabolic flexibility to improve performance?

You want the right fuel at the right time. In other words, you want to burn fat when it makes the most sense and carbohydrates when it makes the most sense. A Paleo nutrition approach is inherently lower in carbohydrates and supports your body fueling more from fat. Aerobic training (training at or under MAF effort) also favors burning fat over glycogen. Thus on days when you’re not training or you’re training easy, you need fewer grams of carbohydrate in your diet.

Conversely, on days when you plan to go hard. Your body needs more carbohydrates. In this context, it’s valuable and appropriate to consume a higher concentration of carbohydrates both prior to and during exercise.

You can improve your body’s metabolic flexibility - especially fat adaptation - by focusing at times on extended periods of MAF training and lower carbohydrate eating. This is important because the human body (on average) more easily and preferentially consumes carbohydrates (glycogen) while being slower to adapt to fat consumption.

So, what does periodization look like? During aerobic base building phases, eat a Paleo diet that includes fewer starchy tubers like potatoes and yams. When your training starts to add intensity, start adding more carbohydrate to your diet from sources like fruit and starchy vegetables such as sweet potatoes, yams, and even red or white potatoes if you can tolerate them.

For inter-workout fueling, look for super starch fueling products that are low in sugar. Super starch products won’t spike your insulin or blood sugar and will allow you to cintinue accessing fat as a fule source during extended periods of exercise while also benefiting from extended access to glycogen.

Cognitive Performance & Athletic Performance - Can you improve the synergies between them?


Optimizing your cognitive performance can help you optimize your athletic performance by reducing your allostatic load. Boom! It’s that simple. Let me explain...

While we all share a passion for running, none of us are professional runners. Rather, most of us are working professionals. And chances are, most of us are engaged in knowledge work that often places us under high cognitive load for extended periods of time.

Operating for extending periods of time at high cognitive load, coupled with other factors in professional work environments, creates high levels of stress. What’s important about that fact is that our body doesn’t differentiate between work stress and training stress. It all contributes to our allostatic load. In other words, training stress isn’t necessarily “good stress”. To be sure, we invite training stress and need it to improve our athletic performance but, in terms of effects on your central nervous system, work stress is no different than high-intensity training stress. So what?

To achieve our athletic ambitions, we want to apply an optimal amount of high-intensity training stress on our bodies to achieve certain physiological adaptations. But what if your allostatic load is too high to reach or sustain your optimal training stress load.? If you press too hard during training, your performance degrades on all fronts, cognitive performance, athletic performance, etc., and you become prone to injury, illness, and emotional disruption among other symptoms.

Under these conditions, you have to relieve stress somewhere, but you don’t want to dial back your training! Where else can you look? Optimizing your cognitive performance can help reduce your allostatic load (by making your job less stressful) which can improve your athletic performance and recovery cycles and potentially prevent you from needing to dial back your training efforts.

Breaking down Cognitive Performance

Cognitive Gears

James Hewitt has a framework for cognitive performance that relates well to endurance sports. In this framework, cognitive performance functions in intensity zones similar to how we think of physiological performance (think aerobic, lactate threshold, and VO2 Max zones for example).

We have a high cognitive gear best suited for working on tasks with the highest cognitive load. Like our VO2 Max zone, we can only function in our high cognitive gear for short periods of time.  We have a middle gear best suited for work characterized by menial tasks and work that has a high demand for switching. We can function in the middle gear for longer than our high gear but, eventually, the lactic acid accumulates and we give in. Finally, we have a low gear best suited for rest, recovery, and reflection. This is our recovery day or easy pace.

Variations in Cognitive Performance

Our cognitive performance can potentially vary as much as 20% throughout the day. Variation follows a three-part cycle in which we experience a peak, a valley, and a rebound. Depending on your chronotype, you will experience these phases of this cycle in a particular order.

Humans are known to have two main chronotypes, morning lark or night owl, although much of the population falls somewhere in between. If you are a morning lark, you will experience the phases of these cycles (from the start of the day) as a peak, a valley, and a rebound. If you are a night owl, you will experience these phases as a valley, a rebound, and a peak. If you fall somewhere in between these chronotypes, you will experience these phases as a rebound, a peak, and a valley.

How Can I Improve my Cognitive Performance?

The top three things you can do to improve your cognitive performance are:

  1. Take control of your daily work rhythm

  2. Reduce task switching

  3. Sleep more

Take control of your daily work rhythm

Just like with your run programming, you want to do the right cognitive work at the right time. Painting in broad brush strokes, think about what your chronotype is and then structure your day to align your variations in cognitive performance with the types of work you do.

For example, if you’re a morning lark, then you likely start your day with a peak in cognitive performance and should thus plan your highest cognitive load work (focus, analysis, creation, etc.) for the early part of the day while you’re in your peak zone. During extended periods of work in our high cognitive gear, it’s still important to rest. Experiment with and practice time management methods such as the Pomodoro Technique or Getting Things Done.

During your valley, take time for rest and reflection. Have a quiet lunch, meditate, go for a walk, and process your thoughts. You could even do some simple exercises to improve mobility and combat another ill of knowledge work: sitting too much.

During your rebound, you're in your middle cognitive gear and should focus on work that is menial and requires a lot of switching like administrative work, clearing your inbox, or loading up on meetings (gasp!).

Reduce Task Switching

Task switching doesn’t necessarily slow down your productivity. Studies show that humans compensate for task switching (think multi-tasking) by working faster. However, while task switching may not undermine your productivity, it is frustrating and the increased time pressure and complexity that come with task switching make your work inherently more stressful.

The ideal time to avoid task switching is when you’re in your peak cognitive performance zone doing work that requires focus and analysis. One way to avoid task switching when you're in your peak cognitive performance zone is to turn off and hide distractions. Turn your cell phone ringer off, flip your phone over or, I dare say, turn your phone off (blasphemy!). Similarly, turn off your desktop notifications for things like email, Slack, the Apple Messages app, or anything else that can pop up on your desktop and distract you.

It’s also a good practice to avoid switching in other areas of your daily life. For example, when you're in the restroom, in line for a cup of coffee, or driving, avoid checking your phone or surfing social media. Instead,  take time to think, reflect, listen to music, or basque in silence. You may have to take drastic measures (like me) and delete all of your social media apps (ahhhhh!!!!!).

Sleep More

Simply put, getting adequate sleep will improve your cognitive performance in numerous ways. Listen to this podcast and/or this podcast to learn why and how to improve your sleep.

Brief Conclusion

Improving your cognitive performance can reduce workplace stress allowing training stress to take on a higher proportion of your allostatic load. You can improve your cognitive performance by taking control of your daily work rhythm, avoiding task switching, and sleeping more.

Change can be tough. Try to find companions to work through change with you. Convince others on your work team or in your family to try a small change with you (or challenge your team to do this if you manage your team). That change could be a sleep challenge (get 30-6- more mins sleep), a challenge to see who can reduce screen time (tracked through your smart phone’s screen time stats app), or an intentional restructuring of work days to better support cognitive variation.

In terms of change, focus on the process, not the goal. Failure is a part of the journey toward the ultimate goal, not an obstacle to achieving your goal.

Finally, don’t let perfect be the enemy of good enough. That applies to all facets of life and especially work. To be sure, I love high standards and I have exceedingly high expectations for myself and others but, like with anything in life, we have to have some sense of moderation.

Agile Training and Coaching - The Rogue Model


Agile Methodology is a project management framework developed specifically for the software development context. Wikipedia is at times great with words, so I’ll borrow a working definition here: Agile Methodology “advocates adaptive planning, evolutionary development, empirical knowledge, and continual improvement, and it encourages rapid and flexible response to change.”

I first encountered the agile methodology in my bygone corporate career. I instantly fell in love with the methodology. As I reflect on my training history as an athlete, I see I’ve intuitively applied the Agile Methodology to my own training for the better part of a decade. And now I embed this methodology in my coaching philosophy.

Agile Training and Coaching

Let’s break down our working definition. Adaptive planning in a coaching context is the practice of understanding an athlete’s unique circumstances (running history, motivation, talent, race goals, nutrition habits, sleep habits, injury history, etc.) and developing a plan that best suits their circumstance and goals.

Evolutionary development and continual improvement flow from the collection of empirical knowledge (e.g. HRV, heart rate data, or pace data) and, in this case, non-empirical knowledge (i.e. subjective feedback) coupled with the practice of rapid and flexible response to change.

There is a specific communication style unique to the Agile Methodology that facilitates this process. It’s called Scrum. Essentially, teammates communicate frequently for short periods of time amongst themselves and with project stakeholders. In the case of Agile Coaching, communication is between coach and athlete plus other potential teammates such as a medical practitioner, nutritionist, and/or strength and conditioning coach.

As the coach and the athlete meet (standup) regularly and review objective and subjective feedback, the coach can make inferences about how the athlete is responding to training stimulus and other environmental factors (like lifestyle changes, work stress, etc.). As necessary, the coach can adjust the athlete’s training plan in real time. This process of planning, executing, gathering feedback, and adapting a plan is known as iterative development and is the heart of the Agile Methodology.

In sum, in an Agile coaching and training context, a coach and athlete work together (perhaps with a broader team including medical or coaching professionals) to develop an individual athlete plan. This initial plan is high-level. It might include a few key races and cycles of base development, peaking, and recovery that support the key races. Keep in mind that, in an agile context, this initial plan is always subject to change.

From an initial high-level plan, the coach and athlete will plan an increment of work to execute (say 4-6 weeks). Then the coach and athlete will break that work down into smaller increments called sprints. Sprints last one week. The coach and athlete may meet daily or once per week to gather feedback and determine the necessity of iterating on the plan from week-to-week (this is flexible and rapid response to change).

The Daily/Weekly Standup

The stand-up is a cornerstone of Scrum communication. Stand-ups are short meetings intended to keep team members constantly informed of progress and obstructions. Software teams stand-up daily for 15 mins to discuss what they did yesterday, what they’re doing today, and whether anything is blocking them from accomplishing their mission.

In a coaching context, the more that coaches and athletes communicate, the richer the process and outcome are. Coaches and athletes will discuss training progress and subjective lines of inquiry about the athlete’s physical and mental state.


Agile Methodology is all about team function. An athlete and a coach are a team uni. The athletes plays a vital team role in agile. The athlete is closest to the information about their readiness to train.

Athletes must listen to their bodies, ask tough questions of themselves, and learn to use objective data along with their subjective feelings to make good decisions.

And athletes must communicate with their coach about what they’re feeling, how they’re training is progressing, and how motivated they are.

Software is never done…

There is a saying in software that a product (or project) is never done. Philosophically, this means that there is, by design, no end to the evolutionary development process. This philosophy holds true for the athlete in you. You’re engaged in a continuous process of living as a better version of yourself. You’re on a ceaseless journey toward mastery.

Group Coaching

I’ve talked a lot about the coach and athlete. This model still works in a group context. I am able to see and interact with the team up to three days per week and I’m able to see them run, not just exchange words.

And to keep the decentralized agile model alive, I offer multiple workout options for each day (i.e. easy run vs. workout vs. stay in bed) and provide tools (content) to help athletes make the decision about what work they should do each day. And, if they’re not sure on a group run day, I’m with them at practice to serve as a sounding board for advice.