Carbohydrate Needs for Strength and Power Sports
During periods of high-volume hypertrophy or work capacity training, up to 2.5 g of carbs per pound of bodyweight per day might be needed. In contrast, for strength, power, and speed work phases, most athletes can meet their minimum needs with about 1.0 g of carbs per pound of bodyweight per day. In the context of the average sport diet and the average western diet, this is quite a low number, but it makes sense for many strength and power sports.
While heavily dependent on differences in training volumes and daily activity levels, an average intake of 1.5 g of carbs per pound of bodyweight per day is a good rough start for a strength or power athlete. This baseline intake can be modified from between 1.0 to 2.5 g per pound per day based on activity levels and training types.
Carbohydrate Needs on a Hypocaloric Diet
Carbs have powerful anti-catabolic properties, so dropping them very low on a fat-loss diet can result in muscle loss. Assuming a dieter is engaging in hypertrophy training and some form of sport training or cardio to help stave off muscle loss, around 1.0 g of carbs per pound of bodyweight per day is our minimum carb recommendation. Anything below this recommendation would lead to glycogen depletion in most major muscles, chronically low blood glucose levels, decreases in the chemical milieu that supports muscle size, and would hamper high-volume and high-intensity training that also contributes to muscle retention. Lower intakes can be handled for shorter periods (e.g., on rest days). As glycogen becomes severely depleted, it must be refilled in order to prevent muscle loss.
During fat-loss diets, the CCH plays a larger and larger role as calories are decreased. With less calories to work with, the options for various macronutrient ratio combinations begin to shrink–all macros might need to be at or near their minima by the end of a hard fat-loss diet.
Thus, the optimal amount of carbohydrates recommended on a fat-loss diet becomes the maximum amount of carbohydrates that fit within the CCH constraint when protein and fats are brought to their minimum.
Carbohydrate Needs on a Hypercaloric Diet
A minimum of 1.0 g of carbs per pound of bodyweight per day is recommended to support muscle gain on a hypercaloric diet. Anything much lower would reduce insulin secretion and necessitate such a high fat and protein intake that muscle gain would be much more difficult and much less effective. Gaining muscle on lower carb intake is possible, but less probable. As we have discussed, the performance and especially glycogen- and insulin-mediated potentiation of anabolism that carbs promote lead us to recommend their maximal consumption (within CCH) for optimal muscle growth on a hypercaloric diet.
FATS
There are four main classes of dietary fats:
•Monounsaturated fats
Fatty acids with only one double bond in their fatty acid chain. These molecules can exist in cis or trans configurations, the latter of which is the fourth class.
•Polyunsaturated fats
Fatty acids with multiple carbon–carbon double bonds in their fatty acid chain. These molecules can also exist in cis or trans configurations.
•Saturated fats
In saturated fat, no double bonds between carbons exist, allowing maximum hydrogen bonds so that the molecule is “saturated” with hydrogen.
•Trans fats
Trans describes the configuration of an unsaturated fat. In unsaturated fat, double bonds between carbons exist, preventing hydrogens from bonding and thus preventing “saturation” with hydrogen. Due to this, the carbon chain extends from a double bond in only two directions and can either extend from the same side (cis) or from opposite sides (trans) of the double bond.
Essential fats, much like essential amino acids, are fats that are critical to survival and health, but that cannot be made by the body and so must be consumed. The two types of essential fats in the human diet are Omega-6 and Omega-3 polyunsaturated fatty acids. Both occur in a wide variety of foods and can also be supplemented. Very low-fat diets can risk deficiencies, especially for Omega-3s. Further, some vitamins cannot be absorbed in the gastrointestinal tract without the presence of fat, so extremely low-fat diets also risk vitamin deficiencies. Hormone dysregulation can also occur when fats are under-eaten as fats supply some of the raw materials for hormone production.
Figure 3.5 Fats have the smallest impact on body composition and performance compared to other macronutrients.
Minimum, Maximum, and Recommended Daily Fat Intake
Fat Needs for Health
Minimum fat requirements are uniform irrespective of activity level and are matched for health and sport outcomes. The minimum recommendation is around 0.3g per pound of body weight per day–this amount makes it very likely that enough essential fats (Omega-3 and Omega-6 fats) will be consumed to meet minimum needs. In addition, this minimum value ensures enough fat intake to support sufficient testosterone, estrogen, and prostaglandin production for best body composition and performance outcomes. As with other nutrients, there is some variance in this value based on the individual; 0.3g per pound of body weight per day figure covers almost all individuals in most circumstances. In terms of maximum fat intake, current science suggests that as long as fats are not so high as to violate the CCH for carbs, proteins, and calories, the amounts eaten within these constraints can be considered healthy. There is some evidence to suggest that keeping calorie contribution from fat under 40% of total daily calories might be better for gut health and body composition, so this is a sensible maximum to consider within caloric constraints. What types of fats and in what ratios they are consumed can alter health and body composition outcomes. (See chapter 5.)
It must be noted that some individuals will have slightly better bloodwork at lower or higher fat intake levels. If health is your number one priority, trying different ranges and assessing your health with a medical professional via bloodwork is likely a good idea. This means that some people might be able to have a diet that meets minimum carb, protein, and micronutrient needs and is relatively high in fat and still be very healthy. Some prerequisites in quality of food sources would have to be met on such a diet, but it is within the realm of possibility. Unfortunately, such a diet is not optimal for performance or body composition changes.
Fats in Performance and Body Composition Enhancement
The production of testosterone and estrogen relies, in part, on fat intake, and both these hormones are critical to muscle gain, muscle retention, and nearly all performance adaptations. In addition, fat intake supplies essential fatty acids for the production of physiologically active lipid compounds that play key roles in the regulation of muscle growth and repair, particularly through their mediation of inflammatory processes.
Some have argued for fats as a primary fuel source for athletic performance, most recently for ultra-endurance performance. Proponents of this often argue that such performance benefits are not truly realized until an individual becomes “fat adapted” by staying away from carbohydrates almost entirely for weeks on end. As of this publication, there is very little evidence that fat is a high-performance fuel and a wealth of evidence that carbohydrates are the better performance fuel source. As important as