Is there an optimal intake pattern for different goals?

In the chapter on protein requirements. I mentioned Tipton and Wolfe’s contention that any discussion of protein requirements has to be context dependent: that is, the goals of the athlete determine what is optimal in terms ofprotein intake. While they were talking primarily about total daily protein intake, this idea can be extended to other aspects of nutrition including protein intake throughout the day and how it might interact with specific training goals.

Logically, gaining muscle mass versus maintaining muscle mass at maintenance calorics versus trying to maintain muscle mass under conditions of caloric restriction (dieting) are different situations, potentially requiring different optimal intakes of protein, AAs, meal frequency or protein intake pattern. The possibility exists that different patterns of prolein intake (in terms of both timing and type of prolein) might exist for different goals (27).

For practical purposes. I'm going lo consider the following discussion in terms of two different goals: muscle mass maintenance (either at maintenance calories or while dieting) and muscle mass gain. 1 want to note that most of this discussion will be somewhat hypothetical since little direct research exists to date.

The background for this discussion can be derived from a topic I’ve discussed previously in the book in terms of how different patterns of protein digestion (i.e. fast versus slow) can influence whole body metabolism differently.

Recapping briefly, large spikes in amino acid concentration appear to stimulate protein synthesis (recall also the infusion data I discussed above) with little to no impact on protein breakdown. In contrast, maintaining constant low levels of AAs appears to reduce protein breakdown with less of an impact on protein synthesis.

Consuming very large amounts of protein at once (as in the prolein "pulse" studies discussed above) has an effect similar to a fast protein such as whey, spiking blood amino acids and promoting protein synthesis as well as oxidation (28).

In contrast, spreading protein out in smaller amounts throughout the day has an cflcct closer to that of casein, inhibiting protein breakdown with a smaller impact on protein synthesis (28).

I'd mention again that, in the original whey versus casein study, reducing protein breakdown via casein had a larger impact on net leucine balance compared to whey. Recall also that adding whey to other food, which had the effect of slowing down digestion, had a similar effect.

Given that data, it may very well be that simply maintaining relatively constant low levels of amino acids (with a spike around training, discussed next chapter) is optimal for all goals. This would be conceptually similar to the strategy of keeping insulin low but stable during the day with a spike around training. This is essentially the strategy that bodybuilders have empirically settled on under all situations: they eat small amounts of protein, carbohydrates and fat throughout the day with a relatievely larger intake of nutrients around training.

With regards to musclc mass maintenance and dieting, there is little to discuss: based on the direct research available as well as the general difficulty in stimulating protein synthesis when calories arc reduced, a slow/spread pattern of protein intake is clearly optimal. 1 Maintaining continuous low levels of amino acids throughout the day (in addition to increasing total protein intake) to limit the body's need to mobilize stored body protein from musclc and other tissues should be the goal. A combination of slow proteins combined wilh evenly spaced meals lo keep blood AA levels stable throughout the day would seem to be optimal.

But is this also the optimal pattern for gaining muscle mass? On the one hand there is the suggestive study above where a group receiving three meals per day gained more LBM than a group receiving six per day; as well there is the research suggesting that maintaining constant levels of AAs might cause skeletal muscle to become "insensitive" to further stimulation; increasing extracellular levels of AAs and then allowing them to fall again appears to be superior. Both of these data points suggest that keeping blood AA levels stable throughout the day might not be optimal from the standpoint of muscle mass gains.

Another recent study throws a wrench in the typically held bodybuilder idea that simply maintaining continuous levels of amino acids with frequent meal feeding is optimal (29). In that study, two groups were compared. The first received three whole food meals while the second received the same three meals with an essential amino acid (EAA) supplement in-between. 1 should note that the study suffered from one huge design flaw: the groups got different amounts of total protein. It should have also tested a group that got 6 w hole food meals and the same amount ofprotein as the EAA supplemented group.

Recognizing that limitation, the study made at least three major observations. The first was that the EAA supplement generated a greater protein synthetic response than the whole meals. The second was that the EAA supplement generated an anabolic response even when given in-between meals. That is to say. the previously consumed meal, which was still digesting when the supplement was given, didn't blunt the effect of the EAA supplement. Finally, the EAA supplement didn't blunt the anabolic response to the meal. Of course, the study didn't examine w hat impact this would actually have in the long-term on muscle mass gains but is interesting nonetheless.

This study suggests that a potential pattern at least worth experimenting with for athletes seeking maximal muscle mass gains would be to alternate between slower digesting meals with faster acting sources (perhaps a whey protein drink or an EAA supplement) throughout the day (25).

It also plausible that a combination of slow and fast protein sources at a given meal could give the best of both worlds: a spike in AAs to stimulate protein synthesis followed by a slower increase to inhibit protein breakdown. Preliminary data that 1 discussed back in Chapter 2 supports that idea as well although it was being primarily applied to protein intake following resistance training. It's interesting to note that old school bodybuilders often consumed copious amounts of milk to gain lean body mass as milk protein is a mixture of whey and casein.

Nutrient Timing Around Workouts

Although most early research examining the role of dietary protein for athletes focused solely on the total amounts ingested, an area of keen interest recently has to do with the timing ofprotein (and other nutrients) around training.

Some researchers have suggested that the timing of protein around resistance workouts may be more important in terms of muscle growth and adaptation to training than the total amount ofprotein consumed (1,2); additionally, various lines of research (discussed below) suggest a role for protein before, during and after training for endurance athletes.

In any case, proper nutrient liming around training has the potential to impact on several aspects of athletic performance. This includes performance during training or competition, recovery between workouts, and the promotion of optimal adaptations to training.

Regardless ofthe athlete or sport, nutrient timing around training encompasses 4 specific phases: the pre-workout meal (generally consumed 1-4 hours before a workout), immediate pre-workout nutrition (immediately before training to 30 minutes before training), during workout nutrition (anything consumed during the workout itself), and post-workout nutrition (nutrients consumed immediately after training). I'll discuss cach in some detail below and provide recommendations in terms of both quantity and type of nutrients that should be consumed. I also want to address some existing controversies and questions regarding the research on this topic as well.

The interaction between carbohydrate and protein

While this book is meant to be about protein, you'll find that in this chapter 1 also discuss other nutrients, primarily carbohydrate. In terms of nutrient timing around workouts, it becomes difficult to separate out the impact of protein and carbohydrate, as they tend to have additive and interacting roles. This necessitates them being discussed together.

It's safe to say that the majority of early research into the topic of nutrient timing dealt with endurance athletes, as that was the main group studied by exercise physiologists for many years. Research has examined prc-, during- and post-workout nutrition for this group although most of it has focuscd solely on carbohydrate intake.

More recently, the role of protein around endurance training has begun to be appreciated and more research on resistance training has begun to appear. Additionally, there is some overlap between different sports and some of the data on endurance athletes can be applied lo other groups such as strength/power athletes or bodybuilders.

I bring this issue up as it's altogether too easy for endurance athletes to think that all they need to worry about is carbohydrates around training to the exclusion of protein. In contrast, strength/power athletes often assume that all they need to worry about is protein intake often ignoring carbohydrate needs. The nature of high level sports training makes that type of attitude misguided for a number of reasons.

Both endurance athletes and strength/power athletes synthesize proteins in their muscles in response to training. As I’ve mentioned previously, the proteins made are different, strength/power training stimulates the synthesis of contractile proteins while endurance training promotes increase in mitochondria and the enzymes involved in energy production. Regardless, promotion of protein synthesis, as part of an overall adaptation to training is important for both groups. As you'll see below, endurance athletes seeking optimal adaptations to training and recovery need to worry about proper protein intake.

With a few exceptions, most strength/power athletes do more in training than just weight room or power training. Various types of metabolic work is often done wilh many sports such as strongman, wrestling or mixed martial arts using large amounts of glycogen during training; this makes proper carbohydrate intake important. Additionally, many athletes train more than once per day; refilling musclc glycogen between workouts becomes crucial for both training and recovery.

My point being that sufficient carbohydrate and protein intake around training is important for almost all athletes. Which isn't to say that each group should receive identical recommendations for carbohydrate and protein intake around training. The specifics of different types of training affect whether relatively more carbohydrate or protein should be consumed.

In general, and this will be rcflcclcd in the guidelines below, strength/power athletes will tend to need relatively more protein and less carbohydrate around training; endurance athletes will generally consume more carbohydrate and less protein around training.

The pre-workout meal

The pre-workout meal encompasses anything eaten by an athlete 1-4 hours before a workout or competition. The primary goal of this meal (beyond being part of an athlete’s daily nutrition) is to ensure optimal levels ofmusclc and liver glycogen as well as blood glucosc; this is all meant to optimize performance during the training session or

competition. Protein, fat and fiber should generally be part of this meal as it really represents a normal meal in the athlete's daily regimen. In general, the pre-workout meal

Should not be skipped if optimal performance is the goal. There are a few exceptions to this, however.

A major exception to this is an athlete who is on the edge of not making weight for a competition and who must weigh in with minimal food in their system. Assuming that there is sufficient time between weigh-in and competition, an athlete in this situation should eat something immediately after weighing in to ensure optimal blood glucose levels and hydration for competition.

Additionally, endurance athletes occasionally perform lower-intensity endurance training in a fasted state in an attempt to improve their body's utilization of fat for fuel and drive further endurance adaptations. Similarly, bodybuilders and others often perform low- intensity aerobic activity (generally first thing in the morning) without eating in an attempt to lose fat: whether fasted cardio actually generates greater fat loss is debatable and beyond the scope of this book. However, very low intensity (aerobic) workouts generally don't require as much attention to pre-workout nutrition as higher intensity workouts such as weight training or higher intensity conditioning workouts.

The final exception, and I'll discuss this further below, has to do with athletes who must train first thing in the morning. It's often unrealistic to consume a whole food meal one or more hours before early morning training without having to get up so early as to interrupt sleep and recovery. Depending on how long an athlete has between waking up and their first training session of the day, a true pre-workout meal may or may not be realistic. With an hour or more before training, a small solid or liquid meal may be possible. With less than an hour, only immediate pre-workout nutrition (discussed in the next section) may be viable.

In terms of pre-workout meals, most of the research done to dale has focused on endurance athletes and has examined the impact of carbohydrate and/or dietary fat on performance with little to no research examining protein consumption (3). Little has looked at the impact of the pre-workout meal on strength/power athletes.

A mixed meal, containing carbohydrate, protein, fiber and some fat is generally ideal here with the amount of food eaten being larger the further away from training the meal is consumed. An athlete eating 4 hours before a training session or competition should consume more food than one having their pre-workout meal 1-2 hours before a workout.

This is simply to avoid stomach upset and provide adequate time for digestion. Additionally, the closer to training that the pre-workout meal falls, the more easily digesting foods that should be consumed.

I want to mention that athletes differ in how well they perform with food in their stomach, some seem to do well with a full stomach while others do not; a lot of this depends on how close to training the meal is eaten and liquids may work better if the meal is eaten very clo of performance, energy levels, etc.

As mentioned above, athletes who are forced to train first thing in the morning (who may not have several hours to cat beforehand) may or may not be able to consume a true prc- workout meal at all. With an hour or more prior to training, a prc-workout meal can generally be consumed: athletes will probably want to focus on liquid nutrition to avoid stomach upset. Even a small amount of carbs and protein (i.e. a glass of skim milk or a carbohydrate/protein drink) can boost blood glucose and provide amino acids to improve both performance and adaptation to training. In the ease of an early morning w'orkout where there's no time for even a small pre-w'orkout meal, an athlete should ensure appropriate immediate pro-, during* and post-w'orkout nutrition.

Consumption of anywhere from 1.1*4.5 g/kg (0.5*2 g/lb) of carbohydrates 1-4 hours before w'orkouts has been rccommcndcd to optimize musclc and liver glycogen levels. As mentioned above, the major determinant of how' large the meal can or should be is the length of time between the meal and the w'orkout. So, a meal eaten 3*4 hours before training might contain a full 3.0*4.5 g/kg (1.5*2 g/lb) of carbohydrates, a meal 1 hour before w'orkout might contain 1.1*2.2 g/kg (0.5-1 g/lb) of carbohydrate.

It's important to note that these recommendations w'cre originally determined for endurance athletes who arc typically doing very extensive (multiple hours) of training: strcnglh/pow'cr athletes or endurance athletes doing shorter workouts are unlikely to require as much carbohydrate in the prc*workout meal. Using the lower ranges of recommendations may be more appropriate in this situation.

An additional issue to consider in deciding on optimal amounts of prc*workout nutrients is the nature of the workout. As the volume or intensity of the w'orkout goes up, the pro* w'orkout meal should become larger; as workout intensity or volume decreases, the pro* w'orkout meal can decrease in size. Again, a possible exception would be long*duration low-intensity aerobic training (i.e. a 1-2 hour easy spin by a cyclist) but even there, blood glucose and liver glycogcn can become limiting and ensuring optimal stores with a proper pre-w'orkout meal can help to avoid bonking and performance loss.

Along with carbohydrates, protein should also be consumed although few guidelines exist. In fact. I'm only aware of one study that has looked at the topic at all and it examined the impact of BCAAs more than protein per sc. That study compared the impact of BCAAs (approximately 10 grams of BCAAs along with 12 grams of milk protein, 30 grams of carbohydrate and a trivial amount of fat) to the same drink without BCAAs and more milk rotcin. The drinks were given 90 minutes before a one- hour run. The consumption of the BCAAs prevented testosterone and GH from falling following the run (4).

For the most part, the pre-w'orkout meal should simply be considered a normal meal in the first place. So it should contain similar amounts of protein to any other meal consumed during the day. How much protein that will end up being will, of course, depend on the athlete's total daily protein intake. The greater the daily protein intake, the larger the amount ofprotein that will be consumed at this meal.

On average, the pre-w'orkout meal might contain anywhere from 20-40 grams of protein although much smaller or larger athletes might find that this meal will contain more or less than this. I'd note that, on average, endurance athletes would typically be consuming less total protein and relatively more carbs at this meal compared to a strength/power athlete.

This primarily rcflccts the overall difference in daily diet for the different athletes due to the different physiologic demands of their sport. In addition, some amount of fat, depending of course on daily caloric requirements and intake would also be consumed here, along with a fiber sourcc such as fruits or vegetables.

As mentioned above, in addition to being smaller overall, the closer this meal is eaten to the workout, the more easily digested it should be. Fat intake would be lowered and slowly digesting high-fiber items would be omitted to avoid stomach upset. A meal consumed 3*4 hours before training should pose no real problems in this regards but a meal consumed only an hour before training could causc problems due lo the presence of food in the stomach during intense training.