All posts by rf6307

Wildly inconsistent nutritional information from USA Swimming

USA Swimming offers lots of odd, out-dated, and ill-informed nutritional advice to young swimmers. This series of posts are offered as a corrective.

“Tips for Consistent Nutrition” – By Chris Rosenbloom, PhD, RDN, CSSD (Tuesday, March 21, 2017)

The author starts strong. Competitive swimmers need to focus on ‘eating to fuel training and competition every day.’ Absolutely.

And then says something mystifying.

“Your training will not be helped if you are under- or over-fueled.”

We know what ‘under-fueled’ means. But what is ‘over-fueled’? I mean, is the author giving hilariously obvious advice like ‘don’t walk up to the blocks with a stomach full of fettuccine alfredo?’ 

…too much food can divert blood from working muscles to the gut for digestion.

I guess so.

Plan to eat mini-meals or snacks before a long practice and replenish muscle fuel and fluids after practice.

That is useful advice.

A carton of low-fat chocolate milk after practice can provide key amino acids for muscle repair, carbohydrates for muscle glycogen synthesis, and fluids.

“Low-fat?” Why low-fat? Higher fat milk has more energy to help the athlete perform. There is no reason for teenage athletes to avoid fat.

Consistent Mindset: Do you think of nutrition as something that your parents nag you about? Or, do you take responsibility and seek healthful foods and beverages throughout the day?

Not bad, tells swimmers to take charge of eating more.

Healthy food doesn’t have to mean yucky! Even at your favorite quick service restaurants, healthy options abound.

Yucky? I mean, ‘healthy options abound,’ because fast food restaurants offer high calorie foods and teenage athletes need to ingest lots of calories (I don’t think that’s what the author meant though). Athletes need to know that quantity comes first, and if only fast food is available then just eat it.

And stop it with the ‘healthy food.’ People are healthy (or not), but calling some foods ‘healthy’ is creepy and counter-productive when your audience is young athletes. It is very hard for them to eat enough food to fuel their training, performance, growth, and normal biological functions. Fear-mongering about supposedly ‘unhealthy’ foods is harmful.

It is up to you to think about food as something that can elevate your swimming, and taste good at the same time.

That’s excellent advice.

Parents and coaches can guide a swimmer to healthy foods, but only you can eat the foods to get the benefits.

WAIT! No. Stop. Most parents have no clue what the athletes need to eat, and woe to any young athlete who tries to follow the same ‘diet’ as their parents. It is the author’s job to give good, simple advice about meeting the nutritional needs of adolescent swimmers.

Eating a variety of foods: fruits, vegetables, whole grains, healthy fats, and lean proteins, contribute nutrients that feed your brain, as well as your muscles.

Brains run on glucose. Fruits and vegetables are a terrible source of glucose (only about 25% of the carbohydrate in most fruits and vegetables is glucose). Whole grains – by definition – have less glucose per ounce than refined grains. ‘Healthy fats:’ no glucose. ‘Lean proteins:’ no glucose (unless broken down and repurposed).

But the really bad advice concerns fiber. The first three items on the list are high fiber foods. Fiber is implicated in ‘low energy availability’ and a host of serious metabolic problems for athletes, especially female endurance athletes. Adolescent swimmers need less fiber, not more. As for ‘lean meats,’ increasing the fat content of your diet, including fat from meat, is associated with greater energy availability, athletic performance, and overall health.

Lean meats and fiber are for middle-aged office workers on diets. Adolescent athletes need dense carbohydrate sources and complete proteins with plenty of fat.

Try eating 3 meals and 3 snacks every day during your hardest training periods and take note of how you feel. My bet is you will feel better, stronger, and more energized than when you are eating less food.

Good advice. Eat more and more often.

…there are times when bars or chews or shakes can add needed calories. 

Yes, sometimes you have to go with Gu packets or Gatorade or whatever because that’s just how it is.

Look for wholesome ingredients in these foods: whole grain carbohydrates, naturally occurring sugars from fruit or milk, and healthy fats from nuts or unsaturated oils.

That’s just nonsense.  If the goal is to get extra carbohydrate from a bar, avoid whole grain. Too much fiber. It makes you fuller without providing energy. Athletes need more, not less, energy. And forget the myth about ‘swings in blood sugar’. The 2016 ACSM consensus statement finds no evidence that a food’s glycemic index impacts athletic performance.

Also, there is no evidence that ‘sugars from fruit or milk’ are a better energy source or somehow more ‘wholesome’ than table sugar. Table sugar is half fructose, half glucose and is a measurably better energy source during exercise than either pure fruit sugar (fructose) or pure milk sugar (half glucose, half galactose – a sugar that the body has to convert into glucose). So why should an athlete prefer energy bars made with ‘naturally occuring sugars’? I have no idea, and I doubt the author does either.

Do young athletes risk their future health when they eat saturated fat?

But wait! Don’t the origins of cardiovascular disease begin at an early age and progress into adulthood, and isn’t elevated dietary fat intake associated with the development of cardiovascular disease? Let’s take a look at some typical research in this field:
Coronary risk factors measured in children and young adults are associated with the early development of coronary artery calcification. Increased body mass index measured during childhood and young adult life and increased blood pressure and decreased HDL cholesterol levels measured during young adult life are associated with the presence of coronary artery calcification in young adults.
In plain language, sick kids become sick adults. Overweight kids with high blood pressure and bad cholesterol profiles tend to have heart disease as adults. How many of your swimmers are sedentary, overweight, and hypertensive? Also, fat consumption (saturated and unsaturated) raises HDL (the good cholesterol). If their problem were too much dietary fat, it is hard to understand how they could have low HDL. No studies find that healthy teenage athletes – even those who eat like Katie Ledecky or Michael Phelps – are more likely to develop heart disease as adults. In fact, studies find endurance athletes do well when placed on high fat diets (50% of total calories), that these diets ‘did not result in adverse changes to the plasma lipoprotein profiles‘ (meaning their cholesterol was fine), and did ‘not increase body weight or adiposity‘, which is a research-y way to say they didn’t get fat. The real danger for teenage athletes, especially endurance athletes and especially women, is Low Energy Availability (LEA) which has significant adverse health effects on athletes (and not insignificantly, hurts performance too). One of the better ways to combat LEA: eat more fat. Diets at the upper end of what is recommended by the American College of Sports Medicine – 30% – are associated with top performance and reduction in symptoms of LEA.

1,400 Days and 750,000+ (extra) calories: Math, growth, and varsity baseball (part 2)

This is probably a good time to reiterate that we claim no expertise as nutritionists or dieticians. These posts are based on a lay reading of readily available information, plus a spreadsheet. Math is, after all, the great equalizer.

Where did we come up with that number? Does a 13-year-old athlete weighing 130 pounds really need to eat 750,000+ extra calories to grow to a 17-year-old athlete weighing 175 pounds?

Basically, yeah.

Look at the chart below. Ike adds about 1 pound per month every month until the summer before his senior year. Each pound he adds increases his maintenance caloric needs by 20 calories per day, or 600 calories per 30-day month. By the time he adds 10 pounds, he needs to eat over 6,000 more calories per month just to maintain that weight.

The caloric surplus needed for GROWTH is calculated separately, and conservatively. He probably needs about 2,800 calories to gain a pound of muscle and about 3,500 calories to gain a pound of fat. So each pound added is calculated as requiring about 3,000 excess calories. Add it all up and Ike needs to add 764,520 calories to his current baseline diet over the next 1,400 days.

Bon appetit, Ike!

Weight Maintain Days Monthly surplus Age Date
130 2,600 31 0 13.76 Oct-18
131 2,620 61 600 13.84 Nov-18
132 2,640 92 1240 13.92 Dec-18
133 2,660 123 1860 14.01 Jan-19
134 2,680 151 2240 14.08 Feb-19
135 2,700 182 3100 14.17 Mar-19
136 2,720 212 3600 14.25 Apr-19
137 2,740 243 4340 14.34 May-19
138 2,760 273 4800 14.42 Jun-19
139 2,780 304 5580 14.50 Jul-19
140 2,800 335 6200 14.59 Aug-19
141 2,820 365 6600 14.67 Sep-19
142 2,840 396 7440 14.76 Oct-19
143 2,860 426 7800 14.84 Nov-19
144 2,880 457 8680 14.92 Dec-19
145 2,900 488 9300 15.01 Jan-20
146 2,920 516 8960 15.08 Feb-20
147 2,940 547 10540 15.17 Mar-20
148 2,960 577 10800 15.25 Apr-20
149 2,980 608 11780 15.34 May-20
150 3,000 638 12000 15.42 Jun-20
151 3,020 669 13020 15.50 Jul-20
152 3,040 700 13640 15.59 Aug-20
153 3,060 730 13800 15.67 Sep-20
154 3,080 761 14880 15.76 Oct-20
155 3,100 791 15000 15.84 Nov-20
156 3,120 822 16120 15.92 Dec-20
157 3,140 853 16740 16.01 Jan-21
158 3,160 881 15680 16.08 Feb-21
159 3,180 912 17980 16.17 Mar-21
160 3,200 942 18000 16.25 Apr-21
161 3,220 973 19220 16.34 May-21
162 3,240 1003 19200 16.42 Jun-21
163 3,260 1034 20460 16.50 Jul-21
164 3,280 1065 21080 16.59 Aug-21
165 3,300 1095 21000 16.67 Sep-21
166 3,320 1126 22320 16.76 Oct-21
167 3,340 1156 22200 16.84 Nov-21
168 3,360 1187 23560 16.92 Dec-21
169 3,380 1218 24180 17.01 Jan-22
170 3,400 1246 22400 17.08 Feb-22
171 3,420 1277 25420 17.17 Mar-22
172 3,440 1307 25200 17.25 Apr-22
173 3,460 1338 26660 17.34 May-22
174 3,480 1368 26400 17.42 Jun-22
175 3,500 1399 27900 17.50 Jul-22
Extra Maintenance
629520
Weight Increase (pounds)
135000
764520

1,400 Days, 750,000+ (extra) calories: Math, growth, and varsity baseball (part 1)

Let’s say your 8th grader, ‘Ike’, is a terrific baseball player. At 13 years old, Ike is the youngest player in his league but competes successfully against players who are already playing junior varsity baseball in high school.

Ike is having a lot of fun playing baseball, and it is his goal to keep it going through high school and play varsity baseball as a junior and senior.

Ike is 5’6″ tall and weighs 130 pounds, so his weight is in the 75th percentile for his age. Conservatively, he’s on pace to be 6′ tall by the time he’s a high school senior, and to maintain his 75th percentile weight, he will need to gain about 45 pounds (to around 175 pounds). It turns out that 175 pounds is a fairly typical weight for the current varsity seniors on his high school team.

Right now, Ike eats about 2600 calories per day to maintain his weight. This is fairly standard. Moderately active teenage athletes (training and playing 5-9 hours per week) need to consume about 20 calories per pound to maintain their current weight.

Ike wants to grow at a steady pace over the next 1,400 days or so (that gets him to the middle of the summer before his senior year). How many EXTRA calories does Ike need to eat over the next 1,400 days?

Over 750,000. That’s 750,000+ EXTRA calories, above and beyond what he would consume if he just ate his current 2,600 calories a day for the next 1,400 days.

So is this really a problem, don’t teenage boys just naturally eat a lot? Sure. Hormones drive teenage boys to eat a lot and grow a lot. The average 13-year-old male weighs 100 pounds. The average 17-year-old male weighs 140 pounds (CDC BMI calculator – http://bit.ly/2Ja6YyG).

However, the challenge for teenage athletes is much larger.

First, athletes train. Training requires extra energy. Sedentary people need to consume 12-13 calories per pound of body weight to maintain their current weight. Athletes who train 5-9 hours per week need more like 20 calories per pound of body weight. During periods of very high exertion, it’s more like 25 calories per pound. For maintenance. Not growth. Maintenance.  (Estimated Daily Energy (Calorie) Needs for Competitive Athletes, http://bit.ly/2J6FUQH.)

Second, Ike already weighs a lot so he needs to eat more just to maintain. He is not trying to go from 100 pounds to 140 pounds, he is trying to go from 130 pounds to a minimum of 175 pounds. And he doesn’t want to just gain 40 pounds. He wants to gain at least 45 pounds. More would be better, less would be worse.

Third, Ike has to keep eating all the time. As a baseball pitcher, Ike works hard at strengthening the muscles in his lower arm, shoulders, and hips. If Ike does not eat enough and does not carry enough body fat, he is vulnerable to catabolism – the body’s irritating habit of burning muscle for fuel when other sources are not available. If gaining muscle to support vulnerable joints lowers injury risk, then losing some of this muscle is highly undesirable, even dangerous.

In part II, where we come up with that number of ‘750,000+ excess calories.’

Nutrition for teenage athletes

Disclaimer: I am not a physician, metabolic researcher, or ‘nutritionist’ and make no claim to hold any certification in the field of human nutrition.

I am a concerned parent raising two teenage athletes – one a swimmer, the other a baseball player – and I find that nearly all the expert nutritional advice circulated for teenage athletes appears to be written for sedentary adults.

…I find that nearly all the expert nutritional advice circulated for teenage athletes appears to be written for sedentary adults.

My goal is to discuss some observations and present the findings of my own research into published medical findings. I take seriously what elite athletes say when they speak candidly about food and I want to convey what some elite coaches say about the nutritional needs of their athletes when the topic is performance, not nutrition.

This last part is important. When speaking about performance and athletic goals, experienced athletes and coaches say some astonishing things about what and how much they eat. This information does not regularly make its way into the advice offered by nutritional experts.

When speaking about performance and athletic goals, experienced athletes and coaches say some astonishing things about what and how much they eat. 

I beg your indulgence in my use of pronouns. My son plays baseball. My daughter swims. I use ‘he’ and ‘she’ respectively when I write these posts because I am thinking about my own kids. I am not implying anything about the relationship between specific gender identifications and specific sports, nor do I think I have anything significant to say about other people’s gender identifications or their choice of athletic or recreational pursuits. Whoever you are and whatever sport you choose to do (or not do), good for you and good luck.

One post will look at the number of extra calories a hypothetical male teenage baseball player will consume to grow from 130 pounds in 8th grade to 175 pounds when he walks onto the field as a varsity player in his senior year. Another post will look at the energy needs of a hypothetical female teenage competitive swimmer looking to gain strength and drop time. There may be other posts as well.

As always, thanks for reading.