In the last post, I argued that sports drinks, energy boosts, and supplements are unnecessary for most young athletes in most situations. Hydration can be accomplished with water, and sports drinks are appropriate only following (occasionally during) an activity that is truly vigorous, occurs for an extended period of time, and/or takes place in very hot conditions. Supplements are unnecessary if the athlete is eating a balanced diet, and energy drinks are designed to mess with neurochemistry in a way that just doesn’t make sense for kids. Meal replacement bars are convenient when multiple games are being played in one day, but there are good alternatives to the sugar-filled options on most store shelves. Try this and this.
In this entry, I want to discuss sports nutrition and how it relates to the health and development of our kids. Note that I didn’t say “performance” – that should NOT be the primary focus. As soon as we start using “optimal performance” as a guiding principle in a child’s diet, we run the risk of ignoring their long term health and development.
Nonetheless, because of the physical demands of the sport, many current soccer nutrition recommendations are extrapolated from studies of elite athletes or are intended for intense endurance sports, and it is not clear that those studies make sense in the context of kids. Let’s first look at some of the conventional wisdom (CW) you will hear from many coaches:
CW1: Carbohydrate loading is a strongly recommended part of pre-game preparation.
This CW is derived from the following notions:
- Our fuel during athletic activity is glycogen, which is carbohydrate stored in our muscles and liver.
- Once that fuel is exhausted, “bonk” will occur.
- Studies have shown that glycogen levels can be maximized by eating large volumes of carbohydrate the night before an athletic activity, with an additional “simple” carb re-feeding a few hours prior to the event.
CW2: High fat diets are detrimental to performance.
This CW is derived from the following notions:
- Fat delays the emptying of the stomach, directing blood flow and energy to digestive activity and away from “performance”.
- Fat is an “inferior fuel” because it is metabolized more slowly and requires more oxygen for conversion to energy.
- Fat and cholesterol derived from animal products are not “heart-healthy”.
CW3: …therefore a standard soccer diet should be high carb, moderate protein, and low fat.
This CW is derived from the following notions:
- High levels of carbohydrate will ensure that there is always a full reserve of energy at the athlete’s disposal.
- Those carbs plus the protein will promote muscle repair.
- The low degree of fat consumption ensures that digestion is rapid and efficient.
…plus low-fat is just healthier, correct? Maybe not. More on that later.
First, let’s examine CW1 so we can understand glycogen storage and expenditure a bit better. Glycogen is stored in two places: your muscles and your liver. We will only consider muscle glycogen here, since that is the energy used during athletic performance. A typical adult will store about 350 grams of muscle glycogen, which corresponds to ~1400 kcal (1 “dietary” Calorie = 1 kilocalorie). It turns out that this is about how much an ELITE soccer player will use during a 90-minute match. So, it would not be surprising to see “bonking” from a player who had not loaded up with carbohydrates to increase glycogen capacity. Ask yourself this, however: are our kids are really performing at the level of intensity we see from elite adult players? Not likely. I would argue that carbohydrate loading is unnecessary in the case of youth sports – unbalancing the diet in the name of improved performance is unwarranted. It is certainly true that a meal a bit higher in carbohydrate after a game will help replenish glycogen faster, but that is not the same as gorging on carb-rich meals in the name of swelling our muscles with stored fuel.
It is also interesting to read the list of carbohydrate sources suggested by a number of typical sports nutrition guides: pasta, pancakes, waffles, pizza, bagels, breakfast cereal, pretzels, animal crackers, fig newtons, vegetables, potatoes, and fruit. With the exception of the last three items on this list, the suggested carbohydrate sources are highly processed, more easily digestible (and with a higher glycemic index) than whole foods, and in most cases have ample added sugar. Thus, it appears that commonly practiced approaches to carbohydrate loading involve the intake of highly processed carbohydrates and sugars – we have all heard of the pasta dinner the night before the marathon, correct?
It is disturbing to note that both recent and decades-old research strongly suggest that ingestion of sugars and processed carbohydrate such as those listed above can lead to hormonal (endocrinological) imbalances, especially those involving insulin sensitivity, that promote or exacerbate diseases such as type 2 diabetes, cancer, and obesity. You can read more about the negative impacts of processed carbohydrate and sugar here, here, here, here, here, here, here, here, here, and here (videos). In light of this, Robb Wolf wrote an outstanding short piece on how to deal with the need for carbohydrate loading given the downsides of many carbohydrate sources. He also notes that most of the foods favored by athletes are derived from grains, which poses additional problems for those who are gluten intolerant/sensitive. These grain-derived foods may also be pro-inflammatory and increase intestinal permeability, as described in this set of guidelines. Mark Sisson has also discussed the issue at length here, here, and here. Taken together, there is a growing mountain of evidence suggesting that eating grains, grain-derived foods, processed carbohydrate and starches, and sugar is more dangerous than just being “empty calories” (even though the USDA also wants us to eat a carb heavy diet). One should think carefully about whether increasing this load on a child in the name of increased performance and endurance makes any sense at all. What does make sense is focusing carbohydrate intake on items that are minimally processed (fruits, vegetables, tubers) – whole foods are the way to go.
CW2 deals with fat…evil, dangerous fat (note strong odor of sarcasm). I discuss it because it is often held up as the alternative to carbohydrate – any decrease in carb calories would likely be balanced by an increase in fat calories. But is fat really so bad from an athletics point of view? Yes, eating a high fat meal will slow down gastric emptying, and everyone knows that athletic performance is not promoted by a full stomach. Instead, pre-game meals might consist of some lean protein, fruit, maybe some sweet potatoes, and my favorite, medium chain tryglycerides or coconut oil, which DO NOT delay gastric emptying and DO serve to delay the consumption of glycogen stores (maybe that is a topic for a future post – in the meantime, you can start reading more on your own here).
The notion that fat is metabolically more aerobic (requires more oxygen) than glucose burning is not necessarily such a cut-and-dried fact. Dr. Peter Attia holds your hand through all of the molecular biology and chemistry in this post, in which he shows that fat is actually a very effective fuel for athletic performance. You can read more of his thoughts on the subject, as well as seeing him work out without carb loading here. Robb Wolf and Mat Lalonde have also shared their experiences with exercise sans carbs here. There is also this excellent old paper describing studies of folks eating an exclusive meat + fat “eskimo” diet, although not in the context of athletic performance, and this very new paper showing that once subjects are fat-adapted, performance does not suffer in the face of decreased carbohydrate consumption. Finally, there is this valuable resource by Volek and Phinney on performing without a carbohydrate-centric diet, in which they illustrate that fat is a perfectly viable fuel, and is in fact preferred. Even a super-lean person with 2% body fat has enough energy in fat stores to avoid bonk in almost any athletic pursuit. (DISCLAIMER: I am not recommending that children be fed a ketogenic diet, it just happens that most of the folks who think and read extensively about fat burning happen to also be in ketosis.)
Ok, so even if fat is a decent fuel, it is going to clog your arteries and send you into cardiac arrest, correct? Ummm, probably not. There is a long story behind why we think fat is bad, and Dr. Research, Peter Attia tells that story here. Gary Taubes has also written on the subject. In a nutshell, cholesterol and saturated fat are probably not the enemy (although trans fats are still to be feared). Cholesterol is also unfairly demonized; Peter has written a 9-part series on the molecular biology and utilization of cholesterol that clears up much of this – start with part 1 here. I won’t spend any more time on this – take some time to dig into the sources I provide above and start breaking yourself of this irrational fear of fat.
To summarize, eating a bunch of fat before a game (except for MCTs) is not advisable unless you are truly fat adapted. You will feel full, disgusting, and lacking in energy. However, a shift away from carbohydrates as a main energy source should not be feared. Fat is a good fuel and it will not kill you – it may actually be a good alternative to processed carbohydrate for some people.
Ok, so I have already hit on the key points that drive CW3 in the paragraphs above, so I won’t belabor the issue. I have discussed why a carbohydrate-loading approach doesn’t make a whole lot of sense for young athletes, both from the performance and from the diet and health points of view. I have pointed out that fruits, vegetables, and tubers should be the main carb part of our diets. Fats have been shown to be good fuel alternatives, should one choose to decrease carb intake, and I have also noted that the demonization of fats is not wise or accurate. All of these thoughts point to an alternate viewpoint in soccer nutrition that does not preach pasta for dinner, a bagel in the morning, a sugary sports drink after the game, and more pasta when you get home. Let’s focus on feeding the kids for the long haul – we shouldn’t sacrifice their future health for imagined and unnecessary short-term performance improvements.
In closing, I will note that some sports are now taking a more measured and logical approach to youth player development; Chad Cook of the Players Performance Institute passed this along to me as an example from the golf world. Even USMNT coach Jurgen Klinsmann has published new nutrition rules for his team. They are notably more inspired than most of the outdated CW – he is carefully balancing health with performance. The Klinsmann rules are:
- Choose the least processed forms of food such as fruits, veggies, whole grains and high fiber carbohydrates.
- Eat fruits or vegetables with each meal. Choose a wide variety of colors for the biggest benefit.
- Include a LEAN protein source with each meal.
- Include healthy fats in your diet like olive oil, nuts, natural nut butters, seeds, avocado, fish, flaxseed and flaxseed oil.
- When you eat within 30 minutes of waking up, you jump start your metabolism. This gives you more energy to get your day going.
- Eat smaller portions more often, spread evenly across the day. No excuses – you should be eating 4-6 meals/day! Aim for all three macronutrients (carbs, protein, and fat) every three hours for optimal fueling.
- Dehydration = Decreased Performance. Drink at least three liters of non-caloric beverages (water/green tea) every day.
- Have a post-workout recovery meal or shake that combines both carbs and protein immediately after your training.
- Fuel first and supplement second. If you are not getting what you need through food, add a multivitamin supplement into your daily routine. Create a smart supplementation program that improves your performance without compromising your health or draining your wallet. Before you take any type of supplement, make sure to check in with your doctor or registered dietitian.
- Aim for eight hours of sleep. If you can’t get eight hours daily, consider power naps when you can. The body recovers and repairs best when it is sleeping.
And to finish off …
The 80/20 Rule: Each meal and snack is an opportunity to fuel your body optimally. Choose the foods that are best for you 80% of the time and incorporate some of those foods that may not be the best, but are your favorites, 20% of the time!