Optimizing Nutrition for Fat Loss and Cycling Performance
Part of “Nutrition (Sports Science)”
Abstract
Nutrition plays a very big role in both (physical and mental) performance during cycling as well as recovery afterward. Add on top of this the goal of fat loss, and the optimization process becomes more ‘refined’.
Content
- How Many Carbohydrates Should You Consume?
- Exercising Around Maximal Fat Oxidation
- Nutrient Timing of Carbohydrates
- The Effect of CHO on Fat Oxidation
- Protein
- High-Protein Breakfasts?
- Protein and Fat Loss
- Consumption of Protein Might Be Better Than ‘Complete Fasting’ In Terms of Fat Loss
- Fat
- Timing of Endurance Exercise To Maximize Fat oxidation
I recommend the following systematic review on the impact and timing of nutrition on physical performance and recovery:
First, for fat loss, we have to estimate our Total Daily Energy Expenditure (TDEE). The following article gives ways of how to do this adaptively and accurately (based on you as an individual with daily varying degrees of physical activity):
Then, on average, we have to consume below our TDEE. For recommendations on how far below TDEE, I recommend the following article/research:
This first part, in theory, is simple. However, we also have to do this in such a way as to maximize cycling performance (and this article, indirectly, can be applied to other physical activities (mainly endurance) as well).
How Many Carbohydrates Should You Consume?
These are the general guidelines for how many carbohydrates you need daily based on training volume in hours:
In what power zone (1–7) you mostly recide in that day/week also has influence on how many carbohydrates you need to optimize performance (i.e. you need less when cycling mostly in zone 2 (endurance) as opposed to zone 4 (threshold)).
Practical Application: When wanting to keep things simple, follow the general guideline above, and deviate when able to calculate/track caloric/macronutrient/carbohydrate needs more accurately.
Exercising Around Maximal Fat Oxidation
T o maximize fat loss, we want to exercise roughly around our maximal fat oxidation. Why? Because the energy/calories required for performance coming from your own fat won’t be detrimental to your training (and potential fitness improvements) e.g. because this doesn’t result in glycogen depletion on its own (and you need to use some of your glycogen stores for performance) i.e. this part of the equation doesn’t have to be refeed/replenished (and, hence, resulting in more fat loss if keeping calories the rest of the day the same = bigger deficit).
Maximal rates of fat oxidation have been shown to be reached at intensities between 59% and 64% of maximum oxygen consumption in trained individuals and between 47% and 52% of maximum oxygen consumption in a large sample of the general population.
Source: Optimizing fat oxidation through exercise and diet — PubMed (nih.gov)
>More trained individuals possess more mitochondria, hence they can burn more fat at higher intensities.
The other part of the equation, which requires carbohydrate replenishment (with exceptions e.g. being in ketosis), does however have to be refeed. This quantity, when being around FatMax (a.k.a. aerobic threshold / crossover point (physiology)), can be calculated by simply taking half of the calories you will burn through exercise. E.g.:
If I have a workout lasting 2 hours@207 watts, which is upper Zone 2 with an FTP of 277, we burn:
207 J/s · (2h·60m·60s) / 25% GME / 4.18 ≈ 1426 kcal
>GME = Gross Metabolic Efficiency (see: kJ to Calories Conversion: How many calories do I burn cycling? (trainerroad.com))
>1 kcal ≈ 4.18 J
Assuming upper Zone 2 is my FatMax, 50% of the calories are coming from my own fat and 50% from glucose/carbohydrates i.e. we only have to refeed ourselves 1426/2=713 kcal = 178g carbohydrates.
>1g carbohydrate = 4 kcal
This, alone, ensures we are in a 713 kcal deficit. Whether this is the optimal long-term caloric deficit depends:
Personally, I do find it much more (mentally) easier to be in a (bigger) caloric deficit due to physical exercise than without (e.g. because I can eat much more if in both scenarios I am in a 100 caloric deficit).
Diet associated with exercise produced a 20% greater initial weight loss. (13 kg vs 9.9 kg; z=1.86 — p=0.063, 95%CI). The combined intervention also resulted in a 20% greater sustained weight loss after 1 y (6.7 kg vs 4.5 kg; z=1.89 — p=0.058, 95%CI) than diet alone.
Nutrient Timing of Carbohydrates
Timing of these nutrients are important as well (but not as important as simply meeting your daily needs):
When it comes to nutrient intake for athletes and active individuals, there exists a hierarchy of needs.
If we look at it like baking a cake, the training stimulus and the total daily intake form the cake itself. The timing of nutrient intake is more like the frosting, which requires the foundation of the cake to do its job. Finally, the more advanced concepts such as nutrient periodization and CHO-restricted training are the decorations on the cake.
Most importantly, proper feeding around training, despite questions of magnitude of benefit, is never detrimental.
Source: [PDF] Nutrient Timing: A Garage Door of Opportunity? | Semantic Scholar
Given the above example of burning 178g of carbohydrates during the 2-hour training session, what I would personally do is by spreading it out into 3 pieces (nutrient timing):
1. 59g carbohydrates pre-workout (approximately 15m before workout for substances with a very high glycemic index e.g. glucose)
2. 59g carbohydrates for the second hour into my session
3. 59g carbohydrates immediately post-workout (with 1/4 of this value going to protein, see: Cycling Recovery Drinks: What and When to Drink After Your Ride — TrainerRoad Blog, Fueling for Performance | Semantic Scholar))
This ensures we are maximizing both performance and recovery (and hopefully fitness improvements).
…our GI system can only process a certain amount of carbohydrates at a given time. Once you exceed that limit, GI distress becomes an issue. For a long time, the standard advice has been 60–90 grams of carbs per hour using a 2:1 glucose to fructose ratio. However, research is emerging that shows that upwards of 140g/hr can be absorbed using a 1:1 ratio.
Source: How to Use Carbs for Maximum Performance — TrainerRoad Blog
Refer to this article for more on nutrient timing:
The Effect of CHO on Fat Oxidation
There are a couple takeaways concerning the consumption and timing of CHO in relation to maximizing fat oxidation (Source: Optimizing fat oxidation through exercise and diet — PubMed (nih.gov)):
- Acute ingestion (and type) of CHO immediately before exercise reduces fat oxidation.
- The effect of CHO ingestion during exercise on fat oxidation depends on exercise intensity. During low- and moderate-intensity exercise, CHO intake reduces fat oxidation similarly to when CHO is ingested before exercise. However, during high-intensity exercise, studies show no significant difference in fat oxidation between fasted and fed states.
- Chronic dietary changes, such as high-fat diets, have been shown to influence fat oxidation. High-fat, low-CHO diets can lead to increased fat oxidation. The specific timeframe for observing this increase can vary but is generally within several days to a few weeks.
Practical application: One could decide to refrain from consuming carbohydrates pre-workout and replenish them post-workout instead to aid recovery and next-session performance.
To take advantage of this indirect glycogen sparing, however, one would need to be in a larger caloric deficit (i.e. a 100 caloric deficit results in the same bodyweight loss, whether more if it comes from fat, carbohydrate, or even protein doesn’t matter netto-wise).
All of the nutrition and hydration choices you make in the 18–48-hour period between your workouts determine whether you have the carbohydrate stores necessary for a high-quality training session. In contrast, your immediate pre-workout nutrition choices don’t do much to change your glycogen stores; they have more impact on how energized you feel.
Source: The Time-Crunched Cyclist: Race-Winning Fitness in 6 Hours a Week, 3rd Edition, p. 22
Protein
The following article describes how much protein you need adaptively as well as their timings:
High-Protein Breakfasts?
Higher muscle functions were observed in subjects who ingested dietary proteins mainly at breakfast than at dinner. These data suggest that protein intake at breakfast may be better for the maintenance of skeletal muscle mass.
Extra (Reddit discussion on this research): https://www.reddit.com/r/science/comments/pahw6l/study_breakfast_is_the_best_time_for_humans_to/
Protein and Fat Loss
According to this video by Jeff Nippard, you need approximately 1.8–2.7 g/kg of bodyweight of protein per day when your goal is fat loss (and 1.6–2.2 when being at maintenance or bulking):
Dr. Alex Harrison from Renaissance Periodization recommends around 1.3–1.8 g/kg of bodyweight for endurance athletes or triathletes that are trying to lose fat:
Consumption of Protein Might Be Better Than ‘Complete Fasting’ In Terms of Fat Loss
This is due to e.g. increasing TDEE (as timestamped above).
Fat
After meeting the required carbohydrate and protein, we are left with fat, which we want to keep at a minimum to ensure we are in a deficit for fat loss while also ensuring most of the calories are being allocated to carbohydrates instead.
The following table gives an overview of the minimum required fat intake per day:
If you like a more percentage-based approach, the World Health Organization recommends a minimum of 20% of total calories:
Timing of Endurance Exercise To Maximize Fat Oxidation
According to the following study, exercising in the afternoon increases maximal fat oxidation more than in the morning, which is further increased through caffeine:
Time-of-day also had a significant effect on Fatmax (all P < 0.01), which was always higher (ranging from 11.1 to 13.1%) in the afternoon than in the morning. Compared to the placebo, caffeine intake increased Fatmax by 11.1% in the morning (36.9 ± 14.4 vs. 41.0 ± 13.1% respectively; d = 0.30; Fig. 3) and by 13.1% in the afternoon (42.0 ± 11.6 vs. 47.5 ± 10.8%, respectively; d = 0.49; Fig.3)
Extra: Studies have shown that the combination of ephedrine and caffeine is superior for fat loss than taking each individually.[1][2][3] As ephedrine can increase heart rate and caffeine may increase blood pressure (in a naive user), the combination tends to have an additive rather than synergistic toxicological profile.[4]
The aspirin is added to prevent blood clotting (which may be a side effect of ephedrine) and to aid in the signal transduction of ephedrine via prostaglandin inhibition.
Source: ECA benefits, dosage, and side effects (examine.com)
