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When Should Triathletes Eat Breakfast, Lunch, and Dinner?

2022 data from more than 45,000 Supersapiens users can give us insights into when and how athletes fuel - and ways we can improve.

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Triathletes are an intelligent bunch. They read a lot about their sport, from training guides to science articles about nutrition or gear, and they do their best to apply what they’ve read to their lives. When Supersapiens, a continuous blood glucose monitor used by athletes around the world, shared data with Triathlete on their users’ training and nutrition habits in 2022, it got me thinking: “What should triathletes do, versus what they actually do?” This is particularly interesting when it comes to fueling workouts. When should athletes eat breakfast, lunch, and dinner, versus when do they actually do it? To answer this, let’s dig in to the Supersapiens data as well as what the science says about meal timing and optimal fueling for your workouts.

The Supersapiens data points are from 46,000 devices shipped worldwide to an athletic audience. On average, those athletes who employed their Supersapiens device used 5.45 sensors each in 2022, in 2.9 million events. In all, 122,667,900 minutes of exercise were logged. Gender and age differences were not disclosed or known. It’s also important to note that though Supersapiens is popular with triathletes, it’s not exclusive to triathletes, so some inferences are being made. Still, the data gives us some interesting insights about nutrition habits and practices.

RELATED: Continuous Glucose Monitoring: Is It Worth It For Triathletes?

Meal timing for workouts

Athletes’ meal timing can affect their performance, recovery, and overall health. Generally, it is recommended that athletes consume meals before and after exercise to provide fuel to support muscle recovery, bone health & energy balance, to name a few important outcomes.

Factors to consider

Many factors impact the decision to eat a meal before a training session. The first will be the duration of that session. The second is the intensity of that session. Mixed into this will be subsequent training during the same day and the total caloric intake required to fuel those sessions.

Another consideration will include what the athlete attempts to achieve in improving body composition via fat loss versus high-performance training. This will affect total caloric intake day on day and compared to week on week.

The training taking place in subsequent days should also be factored in. If it is a long duration (i.e., more than 3 hours), then total caloric consumption for the day may require a meal early on to allow the amount of food to be physically consumed. This would also apply to carb loading and practicing higher carb intake on training days.

The final consideration will be an athlete’s preference and ability to tolerate meals from a gastrointestinal perspective.

RELATED: High-Carb Fueling: How High Can You Go?

First meal of the day

For a session lasting less than 60 minutes, many athletes will likely choose not to eat prior. This is not necessarily a problem if the athlete consumes a meal post-session within 60-120 minutes. It is not advisable if a second session and total energy (calories) for the day demand increased intake. In the case of Supersapiens data, less than 25% of the breakfast events are registered before 6:55 a.m. This would indicate that for the average Supersapiens user, most sessions are being completed in a fasted state. (Note: Athletes could have registered a snack as the day’s first meal. The data cannot determine the timing of the snacks.)

For sessions extending beyond 60 minutes, it would be advised that a small meal of at least 30-50g of carbohydrates combined with some fat (10-20g) and protein (10-40g) be consumed. The exact amount of protein and fat will vary depending on an athlete’s sex, weight and requirements for the entire day (for more on this, read How Much Protein Does a Triathlete Need Each Day?). For sessions extending beyond 150 minutes, consuming a mixed macro meal containing approximately 100g of carbohydrates, fat (10-30g) and protein (25-40g) would be advised.

RELATED: Ask Stacy: I’m Terrible at Eating Breakfast. How Can I Improve This Bad Habit?

Should I eat breakfast before or after a workout?

Breakfast is an important meal for athletes. However, it being the day’s most important meal is context specific. If glucose control interests an athlete, consuming breakfast will result in better glucose control when a carbohydrate-containing meal is consumed later in the day.  If breakfast is not the day’s first meal, it should still be consumed with similar timings & reasoning before an upcoming session. Breakfast timing for post-session fueling should be within 1-2 hours. Ideally, within 60 minutes to maximize glycogen replenishment and maintain muscle protein balance.  A balanced breakfast should include carbohydrates, protein, and healthy fats. An athlete’s total protein intake will be split across the entire day. Breakfast is an excellent opportunity to consume 30-50g of protein, enabling athletes to hit their daily protein intake. Examples include oatmeal with whey/plant protein, fruit, yoghurt and nuts, whole-grain toast with avocado, eggs & salad, or sardines/ham/chicken/tofu with toast & salad.

Data from Supersapiens reveals the users’ average wake-up glucose values were 88 (±15) mg/dL. This is well within the normal range. The duration of the training session will dictate the need for pre and in-session fueling. The average duration of all cycling events is 01:45:14 (with an average of 663 burned Cal). Based on this, consuming a meal before the session would be advisable for athletes completing a cycling session of this duration to perform att their best.

Attempting strength or swimming sessions in a fasted state is not recommended. The caloric expenditure in water is higher due to convection into the cooler and denser medium than air. One hour of swimming in water at 57 F (14 C) can increase metabolism by 350%. Weight training is often intense, yet shorter in duration. Carbohydrate ingestion is more beneficial for training sessions (≥45 min with at least 8–10 sets) than training in a fasted state.

RELATED: The Pros and Cons of Fasted Workouts

What to eat for breakfast

The content of meals is also vitally important to recovery, health, adaptation and performance. Data supplied by Supersapiens showed that the average carbohydrate content at breakfast was 45 grams, while the median protein content at breakfast was 27 grams. The primary concern here is the average protein intake for an athletic population. Typically, an athlete should consume at least 1.6-2.5g/kg/body weight (BW) of protein throughout the day. This would equate to approximately 0.3-0.5g/kg body weight/meal. Per meal, this is usually around 30-40g of protein. (1,2,5)

Two breakfast meal options could be:

  1. Two eggs, 100g chicken/fish/tofu +/- 1-2 piece(s) of toast and salad.
  2. Overnight protein oats with 30g whey isolate or plant protein, with chia and almonds, soaked in 200ml milk of athlete’s choice.

Athletes should consume moderate to high protein at the start of the day, especially after a session. This also results in the athlete not having to play catch-up for the rest of the day to ensure that total protein intake is optimized. If the amount of protein consumed is between 30-40g+, the start of the day is optimized. The athlete is then more likely to hit their total recommended protein target.

RELATED: Ask Stacy: How Important Is Post-Workout Protein?

In terms of fat intake, this will be related to the athlete’s decision to follow either a low carbohydrate/high fat or traditional athletic nutrition program. Typically, fat will commence in the 0.8-1.0g/kg/BW and be bumped up as required. The bump will concern the caloric requirements of the individual athlete. At Fuelin, we base this on the total weekly training hours, current body weight and the athlete’s overarching purpose (body composition improvement vs high performance). Numbers approaching 1.6-2.0g/kg/BW are not uncommon when training volume gets above 20 hours per week to supply enough calories/energy to an athlete.

Sources of fat to include in the diet include (but are not exclusive to):

  1. Extra Virgin Olive, and avocado oil
  2. Omega 3s – fish or supplementation (fish or algae)
  3. Nuts, seeds, grains
  4. Avocados
  5. Dairy products (dietary preference specific)

RELATED: What Is The Right Balance Of Carbs, Fat, And Protein?

Timing of lunch, dinner, and snacks

It is generally advisable for athletes to eat before sessions that last longer than 60 minutes, and certainly for sessions above 80 minutes. It is recommended that athletes consume their meals at least one to three hours before training to allow for proper digestion. This will often be determined by the size of the meal (i.e., larger carbohydrate content) and practicalities (time in the morning of the session). This can be short-circuited to as little as 10-30 minutes before a session if a form of gut training is being practiced. This will impact the perception of fullness and can be an effective way to train the gut.

For recovery following a session, consuming a mixed meal of protein, fat and carbohydrates within 60-120 minutes of completing the session is advised. The anabolic window does exist. However, you have time to shower, get changed, tidy up and sit down for a meal – slamming a protein shake within ten seconds of the last session is unnecessary. Aiming for within thirty minutes is perfect, though you do have up to two hours.

The use of snacks throughout the day can be an effective strategy for improving muscle and liver glycogen replenishment. Snacks can also assist athletes with ensuring total protein intake is fulfilled throughout the day. The combination of protein and carbohydrates has also been shown to accelerate glycogen replenishment for athletes. A point to emphasize is that the total protein intake will likely play a larger role in many physiological processes. This is opposed to drip-feeding amino acids to stimulate muscle protein synthesis (MPS). The reality is that most athletes will have to eat constantly throughout the day, at intervals of three to four hours to hit their total targets anyway.

RELATED: 15 Delicious (And Nutritious!) Snacks for Triathletes

What to eat for lunch and dinner

Low carbohydrate intake would be defined as less than 50g per day. This is typically not recommended for athletes unless supervised by a health practitioner or in special circumstances. A significant increase in fat would be required to adjust for total caloric intake. Typically, a range of 1.8-10g/kg/BW of carbohydrates is recommended for athletes. This amount is determined by total training volume, intensity and individual session duration. Data supplied bySupersapiens revealed that the median intake of protein, fat and carbohydrate content for lunch and dinner was 38g, 28g and 50 g, respectively. When combining these for the day, the median daily protein, fat and carbohydrate intake was 99g, 74g and 144 grams, respectively.

Based on these numbers, we have the following calculations:

Athlete weight Protein Fat Carb
60kg (132lbs) 1.65g/kg 1.23g/kg 2.4g/kg
75kg (165 lbs) 1.32g/kg .098g/kg 1.9g/kg
85kg (187 lbs) 1.16g/kg 0.87g/kg 1.69g/kg
95kg (209lbs) 1.04g/kg .77g/kg 1.52g/kg

As stated, these are not super-low numbers for carbohydrate intake, yet they are lower than expected for endurance athletes. These are the median intake numbers for users attempting to maximize health and performance through a wearable device. Fuelin advises athletes to monitor signs and symptoms of low energy availability (LEA), such as mood, energy rating, sleep quality, and training ability daily. Reductions in these subjective ratings can indicate LEA and lead to Relative Energy Deficiency in Sports (RED-S). As an athlete’s weight increases, a progressive drop in protein occurs, so essentially, the athlete over 61 kg may have been under consuming their minimum daily required protein intake.

Some examples of lunch & meal options include:

  1. 100-200g meat/plant protein option sandwich on whole-grain bread, with salad.
  2. Quinoa salad with 100-200g grilled chicken and steamed vegetables.
  3. 100-200g grilled fish, served with brown rice and grilled vegetables.
  4. 100-200g lean beef stir-fry with rice noodles and steamed veggies.
  5. 100-200g grilled sockeye salmon with roasted potatoes, beets and eggplant.
  6. Freekeh & couscous bowl with 100-200g grilled tofu, served with roasted vegetables and avocado.

RELATED: A 3-Week Meal Plan for Triathletes in 70.3 Training


Athletes have many decisions to make to ensure their daily fueling strategy is on point. The data supplied by Supersapiens is insightful to see athlete behaviour related to food intake, timing and exercise. It may be the starting point to improve athlete education on correct fueling and their requirements. Technology can play a role in influencing athlete behavior in both directions. Athletes have many decisions to make to ensure their daily fueling strategy is on point. Considerations need to be applied to their own purpose of training combined with the volume, intensity and training load of the days and weeks’ training sessions. Ensuring that the timing of the meals before and after sessions is met will assist athletes to be better daily.

The final piece of the puzzle is breaking the total energy requirements into the specific macro prescription to optimize health, performance and recovery. It isn’t easy. Hopefully, the above information provides a framework to begin. As always, reach out to a professional healthcare specialist should you be experiencing issues with your fueling needs.

RELATED: Start Your New Diet Like You Start to Train: Gradually

Scott Tindal is a performance nutrition coach with 20 years of experience working with pro and amateur athletes. He has a Masters degree in sports medicine and a post-graduate diploma in performance nutrition. He is the co-founder of FuelIn, an app-based personalized nutrition coaching program.

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