After protein supplements, its the most popular category of supplements in bodybuilding: pre workout. But putting pre-workout supplements aside for one minute, what are the pros and cons of different types of pre-workout meals? Are high carb foods preferred for a more intense workout or is protein equally important? And what about fat? Is it important to get some of that in your pre workout too? These are all important questions for the avid bodybuilder or health and fitness enthusiast.
Fortunately there has been a good deal of research in this area, which shows that getting the macronutrient mix right can in fact make a significant difference to what you get out of your workout. While pre workout supplements are invaluable, the reality is that most individuals don't use them on a continuing basis (i.e., day-in day-out). So invariably during certain seasons or from time to time, any given individual is going to have to resort to 'normal food' for their pre workout nutrition.
At the top of the list is pre workout carbs. Their the natural intuitive choice for most individuals. If your hitting the weights hard, then naturally you need some carbs to fuel your workout. But this logic doesn't necessarily play out in every circumstance. One of the major factors determining one's need for carbs and their potential for benefit is the particular type of exercise, namely, aerobic or anaerobic.
Endurance athleltes typically have a greater requirement for carbs because the nature of their training requires a high use of glycogen (the body's storage form of carbohydrate). However, an endurance athletes' particular need for carbohydrates pre workout will depend on their training load and the time since their last training session. If there is 12 hours or less between intense training session, then the body struggles to restore glycogen levels back to normal. In such instances carbohydrate pre workout serves as an immediate energy source while also minimizing the use of limited glycogen reserves.
In an interesting aside, new research shows that purposefully restricting carbohydrate intake prior to endurance exercise can result in better overall training adaptions1. It seems that when faced with limited fuel resources, our bodies learn to be more efficient in their use of fuel. This means more fat and less carbs burned during exercise. But the one caveat with this approach is that training intensity must be reduced, simply because the carbohydrate reserves are not there to meet energy demands.
But what about your average Joe Blow who's hitting the gym for a solid weight training session? Are pre workout carbs just as crucial? Again, it depends slightly on the nature of the weight training and the time that has past since the last training session. Higher volume weight training puts a large tax on the body's glycogen reserves because it serves as the primary fuel source with repeated sets of 12-15 reps. But if the reps are down around 3-6, then the body's creatine/phosphate energy system is the primary driver of ATP. So pre workout carbohydrates are more important for individuals doing higher volume weight training. These benefits have been proven in a recent study involving state and national level strength athletes competing in bodybuilding and powerlifting competitions2. But given the research with endurance athletes, its interesting to ponder whether undertaking weight training with depleted glycogen reserves would also result in superior overall training adaptations.
Pre Workout Protein
Pre workout protein is perhaps the most contentious area of pre workout supplementation and food intake. On one hand, you've got the debate as to what type of protein is best, while on the other hand you have the issue of dosage and form. The pro-protein camp argues that providing protein before your workout ensures that you have amino acids and peptides floating around in your system ready to be soaked up by 'hungry' muscle tissue. They also argue that having protein in your system helps to offset the small amount of muscle tissue breakdown that occurs as a normal part of exercise. On the flip side, many will argue that post workout protein consumption is best, as this is the time when your muscles are most hungry and receptive to aminos. Unfortunately, the research in this area is a bit clouded, with a major recent review on the effect of timing of protein intake concluding it has little effect on overall strength gains from resistance exercise3. Nonetheless, there are a number of studies that have shown benefit from protein ingestion pre workout4. If you have been around the gym scene for any length of time, you've probably met people on both sides of the fence; those who swear by pre and post workout protein, while others who will only bother taking protein post workout. In an intersting aside to carbohydrate and protein intake pre workout; there is research suggesting that consuming essential amino acids together with carbohydrate prior to exercise may be more beneficial for enhancing muscle hypertrophy and strength in response to a resistance training program than protein on its own10.
Pre Workout Fat
Some would laugh at the notion that ingesting fat prior to exercise could possibly be beneficial for performance. But to do so requires a very narrow and restricted view of the role of fat within the human body. The most convincing evidence that ingestion of a high fat meal prior to exercise can improve performance comes from work with endurance athletes. For example, one recent study showed that when endurance runners were loaded up on a high carb diet for three days and then feed a high fat meal prior to an exercise test that they performed better than when having a high carb meal5. This was due to the fact that the high blood levels of fatty acids after the meal served to inhibit their use of glycogen during the initial stages of exercise. Overall this meant the runners had more glycogen left when they got to the later part of the treadmill test when intensity was ramped up. But these effects were observed only when runners were fed a high fat meal after they had reached maximum glycogen storage in muscle. The answer to the question of what effect fat ingestion has prior to exercise when glycogen stores are not full is less clear cut.
Still on the topic of endurance athletes, one study showed no effect significant difference in 20km time trial performance when cyclists were given a high carb or high fat meal6. Over the years, there have been a number of studies exploring the effect of high fat meals pre exercise vs high protein or carb, but most tend to show minimal effect on overall performance, despite there being differences in the rates of fat and carbohydrate usage during exercise7, 8. However, a trend has emerged whereby endurance athletes adapt a high-fat, low-carbohydrate diet for 1-2 weeks in an attempt to increase their rate of fat usage during exercise and therefore reduce usage of their most precious fuel source, namely, glycogen. This strategy seems to be effective, especially when followed by a high carbohydrate intake in the 1-3 days leading into competition9. So in the case of endurance athletes, short-term changes such as a few days or even a single high fat meal seem to have little effect on performance, even though they can change the type of fuel (i.e. carb vs fat) that is used during exercise. It appears longer term (i.e. 2 weeks) diet changes are needed to see meaningful improvements in performance.Whether fat ingestion prior to resistance exercise can help or hinder performance is a much less investiged area of research. This makes it hard to draw any firm conclusions about the effect of a high fat meals on resistance exercise performance.
In general terms, however, high fat meals tend to lower the rate of gastric emptying, so one needs to be mindful how close they consume a high fat meal to their workout. As an aside, research on the beneficial effects of low carbohydrate and high fat diets have recently gathered momentum - suggesting that ketone bodies may serve as superior sources of fuel during both endurance and resistance exercise. Ketone bodies are substances produced whenever, there is a hightened level of fat burning, such as during fasting or when on a low carbohydrate diet. Ketones actually yield more energy per gram than glucose or fat so in theory they represent a more efficient fuel source. However, more reasearch needs to be done before definitive recommendations can be made for athletes11.
Pre Workout Meal Ideas
In terms of practical pre workout meals ideas, there are a myriad of options, however, many individuals are guided by meals that poss the least risk to digestive upsets and/or bloating. There's nothing worse than pushing yourself only to be partly regurgitating your last meal while doing so! Another factor that can influence meal selection is a person's typical response to a high carbohydrate or high fat meal. There are individuals who tend to get what is called rebound hyperglycemia from a high carb meal, which is essentially 'feeling low' or a pronounced sense of fatigue following a big surge and drop in blood glucose levels. Yet others may be prone to digestive complaints after a high fat meal. So naturally there's a need to determine the type of meals best suited to ones body. With protein being the most important nutrient for individuals engaged in regular weight training, pre workout meals as simple as some flavoured milk can work for some, while others will prefer more 'whole food' options, like turkey/chicken salad role. Endurance athletes seem to be the one group that can benefit from significant changes in meal composition such as high fat meals (for a period) or high carb meals when a prior training session has finished less than 8 hours earlier.As with most dietary practices, meal selection needs to be guided by options that are both sustainable and practical. With this framework in place, meaningful and lasting changes can be made, be they higher protein, carbohydrate, fat or a combination thereof.
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