5 Foundational Guidelines for Fitness Nutrition

Curious about plant-based diets or intermittent fasting? Eager for info on nutrient timing or postworkout recipes? Want to know more about the seemingly endless stream of supplements promising to make you stronger, faster, and fitter? If you’re interested in fitness nutrition, it’s easier than ever to access a deep well of data, facts, and opinions with a few simple keystrokes.

But this hyperavailability of information comes at a cost.

“One of the epidemics I’m seeing today is ‘infobesity,’” says Ashley Koff, RD, author of Your Best Shot and founder of The Better Nutrition Program. “We’re overwhelmed by information.”

Information overload can make it difficult to understand an issue, make decisions, and stick with a plan. In the world of nutrition, this might look like jumping from one food hack to the next, experimenting with every dietary trend, or trying every supplement in hopes that the next intervention will help you realize your goals.

It might also look like never taking any steps toward your goals at all, because you simply don’t know where to start amid the informational flood.

It’s time to get back to the basics. Enter the big rocks of fitness nutrition.

The big-rocks model, popularized by the late businessman Stephen R. Covey, goes like this: Say you’re trying to fill a large jar with rocks of various sizes. The most efficient way to complete the task is to start with the biggest rocks. With a few of them, you’ll quickly fill most of the jar. Then — and only then — do you fill in the gaps with smaller pebbles.

It’s a striking metaphor for the power of prioritization: If you’re taking on a complex project, “big rocks” suggests you should start with the ­actions that have the largest impact on your desired outcome. Pebbles, after all, form a shaky foundation.

When considering fitness nutrition — and all the advice out there — it’s easy to get distracted by the pebbles while ignoring the big rocks.

“While creatine and electrolytes can support your performance, if you aren’t doing the basics, like following a progressive strength-training program, eating enough calories overall to support your goals, and getting ample protein to help support recovery, supplements don’t matter as much,” says Lindsay Ogden, CPT, PN, Life Time nutrition coach and personal trainer.

Use the following five big rocks to lay a strong foundation for your fitness, longevity, and overall health.

Consider everything you do in a day: walking, working out, socializing, breathing, thinking. Then add the processes that your body undergoes to support these activities: digesting, circulating and filtering blood, fighting infection, building or rebuilding muscle and other tissues.

“All those outputs require energy inputs to work,” says Ogden. “Energy input comes from the calories — ­energy — in food.”

Before you even think about the food sources of that energy, you need to be sure you’re getting enough ­energy in the first place.

“If you’re not getting enough calories, your vitality, energy, strength, and motivation can all decline,” says performance and transformation specialist Angelo Poli, ISSA.

So how much energy is enough? “That depends on what the demand is,” Ogden notes. The energy required to fuel a workout is only one small part of the equation. A larger contributor to daily energy expenditure, she explains, is non-exercise activity thermogenesis, or NEAT: the movements you do as part of everyday living. People with desk jobs and sedentary hobbies burn less energy via NEAT than those whose jobs and hobbies require walking or other physical exertion.

“If you’re not getting enough calories,
your vitality, energy, strength,
and motivation can all decline.”

There are formulas for determin­ing how many calories you need based on weight, gender, and activity level. For some people, tracking calories can be a useful tool to build awareness and ensure adequate fueling. For others, calorie counting can feel time-consuming and joy­less, or is linked to restriction and disordered eating.

Tuning in to your body’s ­hunger and satiety signals can be an ­easier and more self-compassionate ­approach for making sure you’re ­eating enough.

Simply put, the more you move, the more fuel you need. Try to eat an amount that keeps you energized throughout the day without leaving you overly full or tired.

This might be difficult if your fitness journey has included weight loss or food restriction. To start, give yourself permission to eat whenever you feel hungry. Learn to recognize mild sensations of hunger — and honor those cues before you become ravenous. (Find out more about the principles of intuitive eating at “The 10 Principles of Intuitive Eating” and try the easy add-ons at “How to Add More Fiber, Protein, and Antioxidants to Your Plate” to get more of the nutrients that matter.)

Protein is one of the three essential macronutrients that compose every­thing we eat. The other two are fats and carbohydrates, which function largely as fuel. Protein is unique in that its amino acids provide the raw materials for building all the tissues of the body, including muscle, organs, skin, and bones.

“If your body is a brick house, then protein is the bricks,” says exercise physiologist and performance nutrition researcher Mike T. Nelson, PhD.

Protein supplies your body with the amino acids necessary for repairing essential tissues after any challenging activity. The combination of exercise and protein makes you stronger; it also protects your muscle tissue from breaking down over time.

Without protein, Nelson says, “your body will harvest those amino acids from your muscles to survive.”

Protein supplies your body
with the amino acids necessary
for repairing essential tissues
after any challenging activity.

Muscle loss isn’t just a concern for athletes, he explains. Leg strength, grip strength, and VO₂ max — a measure of cardiovascular health — are all commonly cited as being key predictors of mortality. And dietary protein supports all three.

That makes protein more than a strength nutrient; it’s also a longevity nutrient. “The data shows that as you age your protein needs go up, not down,” Nelson notes. Researchers ­believe this is due to a decline in muscle mass. The body’s response to protein also becomes less efficient as we age.

As with big rock No. 1, protein ­requirements vary. Active people should aim to eat about 1 gram of protein per pound of lean body mass per day, says Paul Kriegler, RD, Life Time’s director of nutritional-product development. That amounts to a starting point of 140 grams of protein for a 175-pound person with 20-percent body fat. Intakes higher than this may not provide additional muscle-gain benefits but may help with appetite management.

An even simpler strategy is to eyeball it. “I recommend starting with at least a palm size of protein with breakfast, lunch, and dinner,” says Ogden. From there, work to add more portions of protein at those meals, or consider adding high-protein snacks — protein powders, Greek yogurt, and eggs are great (and quick) options.

Aim to get most of your protein from whole-food sources, including lean meats, seafood, eggs, dairy products, beans, lentils, nuts, and seeds.

(Want to go deeper on protein? Check out “Here’s What 30 Grams of Protein Looks Like,” “How to Eat 30 Grams of Protein at Every Meal,” and the LT Talks episode “How Much Protein Do I Need?“)

Vegetables and fruits are filled with nutrients that can support athletic endeavors and recovery. They’re rich in essential vitamins, minerals, and phyto­chemicals that sustain overall health, immune function, and energy metabolism. Their antioxidants help manage the impact of exercise-induced oxidative stress, reduce inflammation, and assist with tissue recovery.

Some combine high water content with minerals, making them boons for hydration. This can bolster performance and recovery and regulate body temperature.

Plant fiber aids digestion and promotes a healthy gut microbiome. The carbohydrates in vegetables and fruits help athletes sustain their energy levels during physical activity.

How much produce do you need to reap these benefits?

“As with many other dietary guide­lines, the goal isn’t ‘perfect’ but ‘better,’” says Nelson. Try to get at least two — and up to eight — servings of different vegetables and fruits each day. This can include mushrooms; sometimes-maligned starchier plants, like ­bananas and potatoes; and even tea.

Eating an array of vegetables and fruits
— categorized by color —
may be more important than how many you eat.

Go for variety over quantity: A recent 15-year study published in the Journal of Nutrition found that eating an array of vegetables and fruits — categorized by color — may be more important than how many you eat. Green and white fruits and vegetables, the study found, seem to protect against cardiovascular disease and all-cause mortality; red and purple ones are associated with a reduced risk of cancer and all-cause mortality.

Note that whole grains also fall under the “plants” umbrella, says Koff. Though they have been vilified by low-carb marketing campaigns, whole grains can be nutrient dense — full of antioxidants, phytoestrogens, phenolic and phytic acids, flavonoids, and fiber. (If you struggle with blood-sugar regulation, be attentive to portion size and preparation.)

Whole grains are also powerful sources of easily available fuel and energy. Oats, quinoa, barley, millet, and wild rice are just a few options to complement your training.

(Learn more about grains at “Whole Grains: A Close Look.” For guidance on how to eat more veggies, check out “How to Eat More Veggies“. And to learn why fruit is great for you despite what you’ve heard about its sugar content, head to “Why Eating Fruit Is Still Good for You.”)

For digestion, circulation, regulation of body temperature, cushioning of organs, and the health of your joints, skin, and immune system, water is indispensable. Day after day, hydration fights fatigue and improves physical and mental performance.

Conversely, even mild dehydration can lead to impaired cognition and reduced energy. Dehydration can also lead to an increase in blood pressure, as your heart tries to pump blood that is thicker than normal; during exercise, you might experience a racing heart and ­decreased performance.

To offset these side effects, ingest half an ounce per pound of body weight per day, adding ­another 16 to 24 ounces per hour of sweating, advises Kriegler. For a 150-pound person, that amounts to a baseline of about 75 ounces per day.

But, experts say, remain flexible about that amount. “That number should increase or decrease depend­ing on your activity level, body size, and rate of sweating, as well as the temperature and humidity,” notes Poli.

“If you’re waiting until your workout
to start hydrating, you’re too late.”

Alcohol, caffeine, sugar, artificial sweeteners, medications, exposure to pollutants, and stress also affect hydration levels, he adds, so your hydration needs may change significantly from day to day.

Overhydration is possible, but it’s far less common than underhydration, says Poli. “Many people don’t feel the urge to drink until after they are mildly dehydrated. Their thirst threshold is set too high.”

This delay has a big impact on athletes. “If you’re waiting until your workout to start hydrating, you’re too late,” Ogden says.

With this fact in mind, shift your focus from drinking as much water as possible to drinking it consistently. “You don’t need to tote a gallon jug with you 24-7,” says Poli, “but you probably need to make an effort to take a drink more often.” (For a guide to getting the hydration you need, visit “Everything You Need to Know About Hydration.”)

Alcohol can impede athletic performance and recovery in a variety of ways, says Nelson. It affects energy metabolism by hampering the liver’s ability to convert fat to energy, and it disrupts the body’s ability to regulate core temperature, making it harder to cool or warm itself.

Alcohol is also a diuretic, which decreases hydration levels. It can ­interrupt sleep, hindering recovery and athletic preparedness.

On a subtler level, alcohol reduces strength by blunting calcium function in muscle contractions, and at higher doses, it undermines protein synthesis, necessary for building muscle. It can also impair muscle recovery and growth by tamping down growth hormone, which is crucial for muscle development.

In short, it can really set you back.

“Alcohol won’t support performance or aesthetic goals,” Ogden says. “But it’s part of many people’s lives and experiences.”

As far as your fitness is concerned, the goal is to manage alcohol consumption so that its effects on your life and health are minimal. If alcohol dependence is not an issue for you and you’re able to drink moderately, you can probably do so with minimal risk.

The dose makes the poison. ­Exactly what that dosage is, however, has been hotly debated and varies by individual. Some studies conclude that no amount of drinking is safe; other research suggests that light drinking may even boost heart health. Generally speaking, less is more.

“Take inventory of where you are now,” Ogden suggests. “If you’re having 10 or more drinks per week, maybe the first focus is to get below 10 — and then chip away from there.” (Learn more about the health effects of alcohol consumption at “New Research: No Amount of Alcohol Is Healthy?“)

You’ll cover the lion’s share of your nutritional needs for health and performance with these five big rocks of fitness nutrition. Once you feel confident of your footing, begin adding the pebbles that make you feel good. And whenever you feel overwhelmed by all the nutritional advice out there, return to this steady foundation.

This article originally appeared as “The Big Rocks of Fitness Nutrition” in the March/April 2026 issue of Experience Life.