Case Study #1: Simon (20-Year-Old Athletic Male)

by Brian Rigby, MS, CISSN

10 Replies

Case Studies

Case Study #1

Since I started this blog almost a year ago, I’ve written many articles on good practices in sports nutrition, eating for climbing performance, and also on popular myths that ought to be debunked. I hope that through these articles you have been able to make healthy changes to your diet, and as a result have seen your climbing improve.

This is all good, but there’s still something missing—sometimes it’s hard to bridge the gap between theory and practice. For this reason, I’m debuting a new type of feature I’ll be running every now and again on Climbing Nutrition: Case Studies. Basically, I’m going to show you some of the process I would go through were I to see a particular individual as a client.

Though each case study is by nature individual (and therefore not necessarily cut to fit your own physiology), the basic work remains similar—so you should be able to go through the process yourself to come up with your own results.

Alright, let’s begin:

Client Information

Name: Simon
Age: 20
Sex: Male
Height: 5′ 10″ (178 cm)
Weight: 145 lbs (66 kg)

Client’s Reason for Inquiry

I climb 3-4 days each week and ski (teaching and touring) another 2. For a long time, I’ve tried to keep my weight low in order to have the best strength-to-weight ratio, but whenever I make gains on the strength side from my training it doesn’t seem to transfer to my climbing. I’ve been stuck at v5-v6 for about a year now.

My Notes

Simon’s weight and height gives him a BMI (body mass index) of 20.8, well within the healthy range of 18.5 to 24.9. A flaw in the design of the BMI, however, is that it cannot accurately measure fat mass vs. lean mass. Athletes tend to have greater amounts of lean mass (and less fat) than the average individual whom the BMI was designed for, and so in reality Simon is likely even leaner than the BMI indicates (in extreme cases, large athletes can appear to be “overweight” according to their BMI due to muscle mass). Without a body fat reading we cannot know for certain, but it’s probable that Simon has no more than 10-12 lbs of (perfectly healthy) fat he could lose before dropping into an unhealthy range. Thus, as far as strength-to-weight ratio is concerned, losing weight is not likely to yield a major benefit, especially for the amount of work it would require to lose fat below this already low level.

In our correspondence, Simon says he eats around 2,400 calories each day. Since Simon exercises 5-6 days each week, it’s unlikely this is enough calories to support his strength goals. Instead, this amount of energy is likely to be on the lower end of weight maintenance—a sort of metabolic limbo where the body attempts to preserve muscle tissue but doesn’t have enough energy to support muscle growth. Chances are good that Simon could eat significantly more calories each day and still maintain weight, or gain only minimal weight through muscle gain. He will also have more energy to train harder (or longer at a higher intensity), which will have even more significant effects on his strength.

Client Caloric Goal

Using the Harris-Benedict Energy Equation, we can calculate that Simon has a basal metabolic rate (BMR) of roughly 1,675 kcal/day.

Harris-Benedict Energy Equation

  • Imperial: (4.55 * weight in lbs) + (15.88 * height in inches) – (5 * age in years) = BMR
  • Metric: (10 * weight in kg) + (6.25 * height in cm) – (5 * age in years)  = BMR
    • Men: Add 5 calories to the calculated BMR
    • Women: Subtract 161 calories from the calculated BMR

A BMR only covers the essential functions necessary for sustaining life at its most basic level, though; unless Simon is literally lying in bed all day—eating nothing, drinking nothing, doing nothing—we need to multiply it by the appropriate modifier. There are two ways of doing this: the simple, averaged approach; or the more complex, individualized approach. Since Simon has given me a breakdown of his weekly activities, I will ultimately use the individualized approach. First, however, I’ll show you the generalized approach in case you choose to use this method instead.

Harris-Benedict Activity Modifiers

  • Sedentary: BMR * 1.2
  • Light (1-3 days/week): BMR * 1.375
  • Moderate (3-5 days/week): BMR * 1.55
  • Vigorous (6-7 days/week): BMR * 1.725
  • Extreme (6-7 days/week, multiple workouts per day): BMR * 1.9

Since Simon exercises an average of 5-6 days per week (3-4 days climbing, 2 days skiing), he falls into the “Moderate” to “Vigorous” category of physical activity level. “Moderate” has a modifier of 1.55, while “Vigorous” has a modifier of 1.725. Thus, for a more moderate week, Simon will need roughly 2,600 kcal per day (1,675 kcal/day * 1.55), while a more vigorous week calls for roughly 2,900 kcal per day (1,675 kcal/day * 1.725).

Based on this information, Simon’s daily intake appears to be 200-500 calories shy of the recommended amount for maintainance—and low enough to have a noticeable negative impact on his climbing and training. By increasing calories to the recommended amount, he would have more energy, gain strength easier (and transfer that strength to climbing), and still maintain weight.

Really, though, it’s better to individualize your plan whenever you can. The problem with modifiers is that they’re very broad, subject to interpretation, and error-prone. For example, it would appear based on the above list that exercising for one hour three days a week and exercising for two hours five days a week are equivalent, when it’s instantly apparent that they’re not—but two people might still calculate their metabolic rates as equivalent based on the above modifiers, despite having wildly different lifestyles! Furthermore, there’s no concern with intensity. An hour of walking is equivalent to an hour of race-pace running, even though there is a huge difference in the calories burned by each activity. An individual approach overcomes these limitations.

To individualize your plan, you just need to know approximately how many calories your chosen exercises burn, and approximately how long you engage in them each day. There is still room for error (overestimation of intensity or time, for example), but these errors will likely be much smaller in magnitude—only a 25-100 calorie difference across a day, rather than a 200+ calories difference.

The first step in an individualized plan is to calculate your sedentary metabolic rate—your BMR multiplied by the sedentary modifier of 1.2. This sedentary rate accounts for all the little things we do everyday that are not included in your BMR, such as eating, sitting upright, walking around, standing, etc. Simon’s sedentary rate is roughly 2,000 calories per day (1,675 * 1.2 = 2,010).

Next, we determine the average caloric cost of the activities Simon engages in. The easiest way to go about this is to just use an online calculator such as this one and plug in your weight and the activity you’re interested in.

For Simon (weight 145 lbs), ski touring will burn between 400 (for an easy pace on gentle terrain) to 525 (for vigorous effort) per hour, with higher rates possible for certain conditions. Teaching skiing is a little harder to quantify because it’s variable, but light downhill skiing burns roughly 264 calories per hour (this would only include the time actually skiing, not chairlifts, etc.) and it’ll likely be at least that.

According to the exercise calculator, climbing burns about 660 calories per hour, but we can be more specific here based on intensity. Based on this research, climbing burns roughly 17 kcal/minute for easy routes, 19 kcal/minute for moderate routes, and 22 kcal/minute for difficult routes (for an experienced climber). For a new climber, a difficult route—“difficult” is relative to skill, by the way, not absolute based on grades—burns 23 kcal/minute. Bouldering is of higher intensity, so it’s possible that it burns even more calories, but given the lack of data we’ll just assume it burns 22 kcal/minute. This is “on the wall” time only, which varies from person to person, but is likely to average 10-20 minutes per hour for bouldering. That means that each hour of bouldering will burn an average of 220-440 kcal.

Now, all we have to do is multiply each activity’s caloric cost by the time spent doing it and add that to Simon’s daily total. If we assume he climbs two hours per day with an average amount of “on the wall” time, he would burn 660 calories doing so. That means he should consume about 2,660 calories on a day he climbs (2,000 from his sedentary metabolic rate and 660 from his activities) to maintain weight. Or, on a day of ski touring that lasts six hours, he should consume 4,400 calories to maintain weight.

Macronutrient Breakdown

The final step is to determine the macronutrient breakdown of any given day. This is perhaps a little more complicated just because protein needs remain static (roughly 100-160 grams per day) while carbohydrate and fat needs will vary based on total daily activity. Normally when I work with clients, I provide a “base goal” for each macronutrient (in addition to calories) and then a “per hour of exercise” goal as well (with variations according to intensity), but here I’m going to show a slightly easier variation.

First, based on Simon’s BMR of 2,000 calories per day, protein should account for roughly 24% of the calories in his diet (120 grams of protein at 4 calories per gram equals 480 calories, divided into 2,000 calories equals 24%—the 120 grams is the important part). Since this is a sedentary day, we’ll leave carbohydrates towards the lower end at 50%, which leaves fat at 26%. Even though 50% isn’t ideal for aerobic activities such as ski touring, the actual percentage will wind up being significantly higher on ski touring days because protein doesn’t increase. If this isn’t clear right now, don’t worry, you’ll see the math in just a bit.

Simon’s Macronutrients on a Sedentary Day

  • Protein: 120 g (480 kcal; 24%)
  • Carbs: 250 g (1,000 kcal; 50%)
  • Fat: 58 g (520 kcal; 26%)

To determine what his needs will be on non-sedentary days, we’ll figure out the ratio of carbohydrate-to-fat calories. In Simon’s case, it’s roughly 2-to-1 (50% carbs to 26% fat, or 50:26 –> 1.92:1), and he should try to keep this ratio approximately the same on active days as well. That means getting two calories of carbohydrate-based energy for every single calorie of fat-based energy.

For those interested in the gram-to-gram breakdown, carbohydrates weigh in at 4 calories per gram and fat weighs in at 9 calories per gram, which makes the gram of carbohydrate to gram of fat ratio about 4.5:1 (1/2 gram of carbohydrates for every 1/9 gram of fat). This isn’t necessary to figure out the rest of Simon’s macronutrient schedule, though, so don’t worry too much about it.

On days when Simon climbs, he should consume an estimated 2,660 calories (or more or less depending on the total amount of climbing). When the 480 calories from protein are subtracted, we are left with 2,180 calories—66.6% of which should come from carbohydrates, and 33.3% of which should come from fat (that 2-to-1 ratio). That comes out to roughly 1,440 carbohydrate calories (55% of his total caloric intake) and 720 fat calories (27% of his total caloric intake), which is about 360 grams of carbs and 80 grams of fat. So Simon’s climbing day macronutrients look more like this:

Simon’s Macronutrients on a Climbing Day

  • Protein: 120g (480 kcal; 18%)
  • Carbs: 360 g (1,440 kcal; 55%)
  • Fat: 80 g (720 kcal; 27%)

Already you can see that carbohydrates are playing a much more significant role!

Now let’s do the same operation for the ski touring day. Removing the 480 calories of protein from the assumed 4,400 he will burn throughout the day, we are left with 3,920 total calories. At a 2:1 carb/fat ratio, about 2,600 of those calories should come from carbs while 1,300 should come from fat—this is equivalent to 650 grams of carbs and 144 grams of fat. Now, carbohydrates make up about 59% of his diet, fat is about 30%, and protein is only 11%!

Simon’s Macronutrients on a Ski Touring Day

  • Protein: 120 g (480 kcal; 18%)
  • Carbs: 650 g (2,600 kcal; 59%)
  • Fat: 144 g (1,300 kcal; 30%)

The greater Simon’s caloric need, the greater role carbohydrates will play in his day, according to our specified ratio. Moving from a sedentary day to a moderately active climbing day to a significantly active ski touring day, Simon’s carbohydrate goal moves from 50% to 55% to almost 60% while fat only moves from 26% to 30% (and protein dwindles in relative “importance”).

For most people, starting with a similar caloric ratio (roughly 1:2:1 protein/carbs/fat) as the one demonstrated here is probably adequate, especially if you do a combination of anaerobic (bouldering, single-pitch sport climbing, campus training, fingerboarding, etc.) and aerobic (low-intensity multi-pitch climbing, hiking, cycling, etc.) activities. If you’re much more on the anaerobic side of spectrum, you can safely alter the carb-to-fat ratio to be 1.5:1 (45% carbohydrates, 30% fat on a sedentary day) without affecting performance. If you engage in a lot of aerobic activity, you may wish to increase it to 2.75:1 (55% carbohydrates, 20% fat on a sedentary day) or even 4:1 (60% carbohydrates, 15% fat on a sedentary day).

Test in the Real World

Determining theoritical ratios is only the first step for any nutrition plan. After we have a target to aim for, we need to gauge it against real world results, which means implementing the plan and monitoring Simon’s weight. If Simon continues to maintain weight with the increased caloric load, then we know we’ve hit about the right area, and we might even increase calories slightly until we find the point at which he starts to gain weight (so we can be certain he is doing the most for muscle recovery and strength gain). If Simon gains weight, then we’ll back calories off slowly until he starts to maintain again. He shouldn’t lose weight since we’re increasing calories.

Aside from monitoring progress in a concrete way such as through weight maintenance (or body fat readings, if he had a way to do it), Simon should also subjectively feel stronger and more able to translate his training strength gains to his climbing. He should have more energy, recover faster, and stay strong longer. If all of this is true, and his weight is stable, then we would consider Simon’s plan to be successful and he would follow it until his goals changed. If there are problems that persist longer than a week or two (the amount of time it can sometimes take to “break in” a diet), then we’ll make some changes depending on the specifics of the problems.

Wrapping Up

Simon is a great example of an average, active male climber. His focus on staying lean no matter the cost was inhibiting his strength gains on the wall and providing no discernible benefit since he was already quite lean. By increasing his daily calories to a more appropriate level, he should be able to continue to maintain weight while improving his ability to gain strength. If followed accurately for an extended period of time, he may even gain small amounts of muscle and lose equal amounts of fat (AKA “body recomposition”), thereby dramatically improving his strength-to-weight ratio.

If Simon does not resemble you or your goals, don’t fret! This is just our first case study, and I’ll more than likely cover someone with a similar goal or physique to your own in the future. In the meantime, you should hopefully be able to apply the lessons learned from this first case study to yourself (provided your goal is weight maintenance) and get positive results.

If you have questions about this case study, please ask them in the comments below so I can answer publicly on this page and clarify the confusion for everyone! If you think you’d be a great example for a case study, fill out the form on this page and please be patient. I will do my best to answer your needs via email (at the least), or possibly use you as another example in the months to come.

Until next time!

10 comments

  1. Benjamin

    Very interesting from a theoretical point of view. But it seems almost impossible to implement in the real world. How does numbers and ratios translate to real food. It must take a lot of planning just to figure out what to actually eat. Also, how can you time your food intake on a normal workday that leaves little or no room for frequent food breaks and prepping.

    Also, I have been a hardgainer my whole life and I can testify to eating enough calories is no way as easy as stated in post. Seems like you need to eat tons of food in very frequent intervals. Again the macro breakdown leads to a more practical issue: How does numbers translate to real food?

  2. Brian Rigby, MS, CISSN Post author

    There are logistical issues, to be sure—issues that are probably better tackled in a separate post—but let me try to provide a little hope here. Let’s assume Simon will have the chance to eat 5 meals/snacks on a given climbing day. With his base carb requirement of 250 grams, that means he should eat approximately 50 grams of carbohydrate per meal, or just over a single cup of most cooked starchy carbs. A cup is not a lot, so this shouldn’t be infeasible. The remaining 110 grams of carbs that he needs from climbing can come from preloading before exercise (slow-digesting carbs to buoy blood glucose during his climb), intraexercise replenishment (such as a sports drink, or fruit), or afterwards in the form of extra food (over the next few hours, about an extra 2.5 cups of starchy carbs). In this case, I’m only focusing on carbohydrates because they are the most challenging to get enough of for most people, at least without resorting to highly concentrated forms like refined sugars.

    A ski touring day would be more challenging, but since he will presumably be exercising with little break we can rely more on the above-mentioned concentrated sources, which will also be easier to digest during exercise. Dried fruit, sports drink mixed into his water, and granola bars all make it easier to get the necessary number of calories.

    In all cases, it does take planning, but the end result is worth it, I think. Energy will be higher, recovery faster, and training gains will be increased. This isn’t to say everyone must plan like this, but rather than there’s value in doing it if you care to, just as there’s value in putting together a training schedule and sticking with it despite the logistical and motivational problems associated with putting together a weeks-long exercise schedule in advance. But, as I said, I think another post will ultimately do your question/comment more justice, so I’ll try to get one out soon!

  3. Daina Holmes, RDN

    Thank you for this post. It is very helpful. Because I don’t want to pay the $39.95 to read the article at https://link.springer.com/article/10.1007%2Fs00421-007-0501-0, could you help me in determining the number of calories burned per minute for a 115# female for easy, moderate, and difficult bouldering ? I assume the numbers in the case study, 17 kcal/minute for easy routes, 19 kcal/minute for moderate routes, and 22 kcal/minute for difficult routes, are specific to Simon’s weight.

  4. Brian Rigby, MS, CISSN Post author

    The numbers provided were based on the averages in the article itself, which were themselves based on an average weight of 64 kg (141 lb). It’s an imperfect approximation, but we just really don’t have any good data on the caloric cost of climbing so it’s the best I could offer! Based on weight, we could estimate up or down by the same factor as the weight change and get in the same ballpark, so a heavier 160 lb climber might burn 19 kcal/min while a lighter 120 lb climber might burn 15 kcal/min. But, these are only estimates because it’s tough to know precisely how the caloric costs associated with climbing relate to weight compared to how they do for running or other more well-studied sports. Sorry I couldn’t give a more precise answer!

  5. Christian Münch

    I have a question with regard to carbohydrates. Do they include fibre or not? I used the formula kcal from all carbohydrates equals 4*gramms of carbohydrates + 2*gramms of fibre. And then I took the ratio 2:1 for all carbohydrates to fat. Is that correct in your opinion? The fibre should somehow be included since it contributes to the calorie intake.

    Thank you very much and best regards,
    Chris

  6. Brian Rigby, MS, CISSN Post author

    Fiber doesn’t have a significant effect on our caloric intake since it’s indigestible. Some fibers are fermentable by our gut bacteria and those bacteria will release short-chain fatty acids as a by product that will be absorbed and used by the cells lining our intestine and thereby technically add to our caloric intake, but overall the net calories from fiber will be negligible.

  7. Anonymous

    Since Simon is active on most days of the week, there are days when he is not. Compute for his TER on his sedentary days.??

  8. Anonymous

    Since Simon is active on most days of the week, there are days when he is not. Compute for his TER on his sedentary days.

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