Welcome to 2021.  As the year wraps up, as tradition calls for it, you need a resolution! Your #pandemic15  weight gain didn’t budge and the time is now for your 2021 diet challenge! 

Are Your Ready for Your 2021 Diet Challenge?

You are motivated to make the change.  You have thought about it for a while. Spring is coming!  Right!?  You know that dieting doesn’t work, not at least in the long term.  You want to increase your fitness level this year so that you can get to a healthy weight for you.  To make that diet challenge stick, you need good fitness!

I’m here to help you. I have created a 30-day email program to help you with your 2021 diet challenge, step by step, to make the long-lasting changes that you are geared up to make!

Today we will take on nutrition for optimal fitness. In this blog, we will go over the basics to maximize your work out:  

    • Understand the importance of proper hydration
    • Learn about proper pre and post-workout snacks that promote optimal performance and recovery
    • Gain confidence in the preparation of nutrient-rich meals and snacks that support optimal performance

The human body is a dynamic organism composed of molecules, cells, tissues, whole organs, and systems working together to regulate the environment within itself – called homeostasis. Exercise disturbs this balance of homeostasis when the cardiorespiratory and musculoskeletal systems are challenged. Proper nutrition before, during, and after exercise plays an important role as homeostasis is challenged from physical activity, with the organ systems coordinating and adjusting to meet the increased energy and metabolic demands of the body.

Exercise disrupts body systems making them strong and efficient – without disruption, biological systems actually weaken.

Science of Exercise & Nutrition

The response & adaptation of body systems to challenges imposed by movement is called exercise physiology. Nutrition is the science of food, how food nourishes the body and influences health which includes digestion, absorption & metabolism.  Sports nutrition, on the other hand, is the integration and application of nutrition and exercise physiology principles that support training, recovery and performance.  We will harness our knowledge of sports nutrition and exercise physiology principles to help you succeed in your 2021 diet challenge.

Benefits of Physical Activity

Physical activity decreases risk for heart disease, obesity, type 2 diabetes, many cancers, osteoporosis, and Alzheimer’s disease.  It also improves sleep, anxiety, stress, immunity, productivity, and your attention span. No pill can offer so much!

Substantial health benefits are obtained with: 

    • 150 minutes/week of moderate-intensity physical activity or 75 minutes/week vigorous physical activity or a combination.
    • Resistance training – moderate or high intensity – involving all major muscle groups is recommended 2days/week or more.

Use this free at-home workout library if you can’t get to the gym because of the lockdowns.

Fitness Definitions

Physical Activity: Any movement made by the muscles that expends energy past BMR (basal metabolic rate)

Exercise: Planned, purposeful and leisure time activity (activities of daily living)

Physical Fitness: Ability to carry out daily tasks without fatigue and with energy to enjoy exercise 

Levels of Physical Activity:

    • Inactive: No activity beyond baseline (this is considered unhealthy)
    • Low: Beyond baseline but fewer than 150 minutes /week (better for health than inactive)
    • Medium: 150-300 minutes /week (additional and possible extensive health benefits)
    • High: >300 minutes/week (additional and possible extensive health benefits)

Type and Components of Physical Activity:

    • Intensity: How hard a person works
    • Frequency: How often and activity is performed
    • Duration: How long in one session or how many repetitions

Intensity of Physical Activity:

    • Light
    • Moderate
    • Vigorous

Types of Physical Activity

Aerobic activity triggers a chemical reaction that requires oxygen to produce energy.  This type of activity is characterized as moderate-high intensity, long-duration activity. The fuel sources are carbohydrates & fat.  Anaerobic activity generates energy without oxygen which is a high intensity, short-duration activity.  The fuel sources for this kind of activity come from a compound that stores energy that is quickly released called creatinine phosphate and carbohydrates. Many people this time of year desire to lose weight, so ideally, we are looking to get the aerobic activity that uses fat as fuel. Be sure to include aerobic activities in your fitness plans.

Another goal for your 2021 challenge could includecardiorespiratory fitness. To be fit in this way the heart, lungs, and circulatory system are able to work together simultaneously to efficiently deliver oxygen and nutrients to muscles and remove carbon dioxide and other waste. Activities to improve cardiovascular fitness include running, swimming, hiking, walking, elliptical, biking, spin class, aerobic classes, kickboxing, etc.

You may want to increase your muscular strength, endurance or musculoskeletal fitness. Skeletal muscles are attached to the skeleton and allow movement of the body as they contract and relax.  Fitness is the ability of the skeletal muscle to contract and relax to support the movement of the skeleton. Muscular strength is the maximal force a muscle can produce whereas muscular endurance is the sub-maximal force held for an extended time. You can increase your musculoskeletal fitness with weights, weight machines, plyometrics, resistance bands, etc.

If you are having a hard time accessing fitness facilities during these times of lockdowns, to get you started on your 2021 diet challenge, Rachel is pleased to share a free home fitness workout library.

Types of physical activity

Nutrition for Optimal Performance

All movement requires energy. A healthy diet provides energy, optimizes recovery, aids injury prevention and boosts immunity. Get a nutrition tracker that tracks your macro- and micro-nutrients (tracker is free, no credit card required) with nutritional targets prescribed by a Registered Dietitian, for only $2.99/month.

Energy = Calories 

Basic Sports Nutrition Guidelines

Energy needs for activity depend on the type of activity, duration, intensity, bodyweight/size, gender, fitness level, genetics, environment [temperature and altitude].  Your nutrient needs change with increased exercise.  In fact, your total carbohydrate and protein needs increase, while total fat needs decrease.  And very importantly: your water needs increase!


Carbohydrates are the main source of fuel for your body and should make up 45-65% of your energy.  They are stored as glycogen and represent energy in your muscles and liver. Adequate carbohydrate stores are critical for optimum performance. When muscle and liver carbohydrate is used up, your body will not just rely on fat, but also muscle protein for fuel. If depleted, blood sugar levels and exercise intensity decline. Carbohydrates also aid in hydration for metabolism and recovery. Easily digested, high-quality carbs should be eaten pre-exercise. Easily digested carbohydrates should be consumed during exercise over 1 hour

Recommended daily carbohydrate intake ranges from 3 to 12 g/kg:

    • Very-light training program (low-intensity or skill-based exercise): 3-5 g/kg For example golfing, ski jumping, diving, baseball or softball (outfielders/infielders)
    • Moderate-intensity training programs, 60 min/d: 5-7 g/kg. For example soccer, basketball, swimming baseball or softball (pitchers and catchers)
    • Moderate-to high-intensity endurance exercise, 1-3 h/d: 6-10 g/kg For example: Endurance running, cycling, sprint-mid distance triathletes
    • Moderate- to high-intensity exercise 4-5 h/d: 8-12 g/kg. For example: Trail runner, iron man triathlete, ultra-endurance runner

Carbohydrates are found in all plant foods, plus dairy. Great sources include vegetables, fruits, potatoes, legumes, and whole grains such as oats, quinoa, bulgur, farro, plus more

Glycemic Index (GI) provides a way to rank carbohydrate-rich foods according to the blood glucose response after these foods are consumed. Foods with a low GI cause a slower, sustained release of glucose to the blood, whereas foods with a high GI cause rapid, short-lived. Increase in blood glucose. 

    • High GI food examples: bread, potatoes, breakfast cereal, sports drinks
    • Moderate GI food examples: oats, tropical fruits like bananas and mangos
    • Low GI food examples: milk, yogurt, lentils, nuts, fruits like apples, berries, and oranges

Fibre is an important carbohydrate to keep you feeling full, maintain normal blood sugar, aids in heart health and keeps your gastrointestinal tract healthy. The latter is extremely important for immunity, metabolism, and hormone balance/mental health. NOTE: High fiber meals/snacks before workouts can cause digestive discomfort in some individuals.


While essential for muscles, protein also maintains your organs and tissues, is responsible for fluid balance, and immune health. It also plays a role in hormonal balance, influencing how you feel and your metabolism. Protein is most essential to post-workout, not pre-workout, as it is not an efficient energy source, but rather needed for recovery. Excessive protein intake may contribute to dehydration or weight gain. Talk to your dietitian about optimizing your protein intake for your 2021 diet challenge.

Recommended protein intake is 1.2-1.7 g/kg body weight daily. Athletes in rehabilitation, trying to lose fat mass or aiming to increase lean body mass, can consume up to 2.0 g/kg body weight.

Animal-derived proteins (milk, eggs, meat and fish) are high quality because they have adequate amounts of all of the essential amino acids (EAAs), which are building blocks for proteins in our body. 

Besides animal sources, what are other sources of protein? Some plant-based proteins (soy, quinoa, amaranth, and buckwheat) contain significant amounts of all EAAs while most plant-based proteins (legumes, grains, nuts and seeds) are generally low in 1 or more EAAs. A variety of these foods must be consumed in your diet to provide all the EAAs.  A registered dietitian can identify if you have any gaps in your EAA’s.

What About Protein Powders?

Whey, casein and soy protein isolates are the most common on the market. Milk contains approximately 20% whey and 80% casein proteins. Based on their rate of digestion, these proteins are commonly referred to as fast and slow proteins. Soy is more intermediate. Mixing soy, whey and casein is popular for this reason, resulting in constant protein release due to slow, intermediate and fast action of the three.

    • Whey protein: A soluble fraction extracted from milk as a result of cheese manufacturing. Whey protein is considered high quality due to its protein digestibility.  Whey acts very quickly to repair muscle (within 30 min of ingestion)
    • Casein: Is the acid-insoluble fraction of protein, produced from the solid fraction of milk after exposure to an acidic environment. Usually recommended for consumption in the late evening because it takes a long time to digest. The slow and prolonged release of amino acids into systemic circulation is hypothesized to promote a positive net protein balance during overnight fast/recovery period.
    • Soy: A vegetable protein, contains a single protein fraction and at the rate of digestion more closely resembles whey protein. Good use for athletes consuming a dairy-free diet.


Fat is an energy source that supports joints, immunity, mental health, and recovery. Adequate intake also supports hormonal health. Fat should make up about 25% of calories consumed daily. 

Fat intake is typically 1.0-2.0 g/kg body weight daily

Tip: Choose mostly plant fats and fish fats. Your fitness regime will benefit from consuming more plant-based fatty acids and fewer foods containing significant sources of animal fat, due to their anti-inflammatory benefits.

Vitamins & Minerals

These compounds do not provide any actual energy but are necessary for your body to use the energy you get from carbohydrates and fats. You also need vitamins and minerals to convert dietary protein into body proteins (hint: muscle repair!) Intake will significantly impact energy levels, recovery, mood, sleep, bone and blood health, inflammation, immunity and hydration.  Vitamin & minerals should come from FOOD first to meet your daily requirements, with exception of Vitamin D. To learn more, read my post on Vitamin D and COVID. To get your vitamins and nutrients from food, consume a variety of nutrient-dense foods (fruits, vegetables, whole grains, legumes, dairy, lean protein sources, and fortified foods.)

*Get a physical and blood work annually to diagnose and correct any vitamin or mineral deficiencies. Work with a dietitian to  help you get the right lab work ordered and evaluate the results. 


Hydration suports all of the body’s functions, including energy levels, recovery and immunity. Drinking adequate fluids is essential to peak your performance and brain function, support organ function, maintain proper hunger and appetite signals, and aids in your natural removal of toxins. 

Effects of fluid loss on activity include fatigue, short term memory & attention deficit.

    • 2-3% body water loss = impaired endurance performance
    • 3% body water loss = decrease in metabolism
    • 4%body water loss = muscular strength declines
    • 5% body water loss = heat exhaustion

Dehydration from one workout affects your next workout. Staying well-hydrated can help delay onset fatigue as well as protect health and well-being by preventing the physiologically deleterious effect of dehydration.  Heat illness is when dehydration leads to heat syncope (dizziness) or heat exhaustion (heat rash, cramps, syncope, weakness, headache, and mild nausea.) Further dehydration can lead to heatstroke which includes excessive sweating, nausea/vomiting, difficulty concentrations, loss of consciousness, etc. 

Weigh yourself before and after a workout to determine how much water you need to replace. 1 kg (2.2. lbs) weight loss is equal to 1 litre or 32 oz water. Your body can absorb only 1 litre of water per hour so it is best to carry water and drink frequently.

Hydration is an important part of nutrition

Is 8 – 8oz. Glasses of Water Enough?

The common recommendation for sedentary adults is 8 glasses of water a day.  There is no ONE fluid-intake recommendation that works for everyone.. There is a wide diversity of fluid needs for each individual. 

How Do Individuals Know When They are Adequately Hydrated?

    • Noting colour and volume of urine is a practical way to assess hydration status.  Dark colour urine and relatively small amounts are indications of dehydration. 
    • Thirst signals dehydration and a need to drink. Drink when you are thirsty! 
Chart used to determine hydration levels from urine.

Proper Fluid-Intake Tips

For short duration (<60 minutes), low to moderate-intensity activity, water is a good choice to drink before, during, and after exercise. Sports drinks (6-8% carbohydrate) are good options for moderate to high-intensity activity lasting longer than 60 minutes, especially when the goal includes replacing carbohydrates and electrolytes. 

For those who experience high sodium losses during exercise can eat salty foods in a pre-exercise meal or add salt to sports drinks consumed during exercise.  Rehydrate after exercise by drinking enough fluid (water or sports drink) to replace fluid lost during exercise. Replace fluid and sodium losses with watery foods that contain salt (soup, vegetable juice). Replace fluid and potassium losses by consuming fruits and vegetables.

Pre-Workout Tips for Your 2021 Diet Challenge

Ensure that you have fueled up on enough carbohydrates for exercise 1 – 4 hours before the endurance exercise (not required for skill-based or strength-based exercise).  For most people that is 1 to 4 g carbohydrate per kg body weight. You should not be hungry and well hydrated when you start to exercise but not so full that you will stress your digestive system.  Ideally, food eaten before a workout will be a balance of quality carbs and moderate fibre. 

Snack Ideas

    • Banana and nut butter
    • Oats and fruit
    • Applesauce and almonds
    • Brown rice cake and nut butter
    • Wheat pita and hummus
    • Sprouted grain bread and fruit preserve
    • Small sweet potato and nut butter
    • Wheat toaster waffle with fruit
    • Homemade or whole food energy bar*

*Energy bar with whole foods: Larabar, 88 acres, KIND, Rx Bar, Perfect bar, etc.

Post-Workout Tips for Your 2021 Diet Challenge

Your snack and meal after your workout should include protein AND carbohydrates but not too much fat. We don’t want to undo the hard work you have done!

Snack Ideas

    • Low fat milk (or soy milk) with fruit smoothie
    • Hard-boiled eggs and tart cherries
    • Sliced turkey with pineapple
    • Half a turkey sandwich with hummus
    • Sprouted grain bread & peanut butter
    • Tuna salad with avocado on whole wheat bread
    • Dried fruit with low fat cheese
    • Plain yogurt with fruit
    • Cottage cheese and fruit
    • Roasted edamame with dried fruit
    • Whole food bars such as Rxbar, Oatmega, Square Bar, Garden of Life Performance
Turkey and hummus on whole wheat bread.

Meal Ideas

    • Whole wheat pita sandwich with turkey and veggies + pretzels + low-fat milk
    • Rice bowl with beans, cheese, salsa, avocado + whole grain tortilla chips or whole wheat tortilla
    • Stir fry with lean steak, broccoli, bell peppers, carrots + brown rice

Putting it All Together

When we put this advice into the context of a meal it is useful to use the new Canada’s Food Guide healthy plate model.  This model shows that 75% of the plate is plant-based, although the plate can be up to 100 % plant-based.  75% is the minimum proportion of plants to consume to achieve health benefits. Vegetables and grains will provide the carbohydrates you need. The other 25% of the plate is a high protein food. 

Sample plate from Canada's Food Guide. CFG is designed to help you meet your nutrition needs.

Choose healthy fats in moderation because they are energy-dense. Remember that all 3 macronutrients are needed to give the balanced nutrition you need for your 2021 diet challenge. Eating in this pattern throughout the day is the key to eating for decreased risk of disease too.

Rachel McBryan RD, your registered dietitian, can optimize your eating plan for your 2021 diet challenge with a prescribed meal plan for $89 CAN (set up fee, $38 CAN monthly.)  Book a discovery call to learn more about how a registered dietitian can increase your success this time. 

Special thanks to Jeanine Petrucci RD and Kelly Jones RD for collaborating on this blog with me so that you have the information you need to be successful in this year’s 2021 diet challenge!  If you want to join the challenge, Rachel McBryan RD has created 30 days’ worth of content to support you one day at a time.

Sign Up for the 30-Day Challenge

Start the New Year on the right foot and sign up for the 30-day challenge now!


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