How BIG Should You Be for Special Forces

The most common misconception about Special Forces is that selected candidates are scrawny, small, and weak.

While that may be the picture you see in movies, historically, the average selected candidate is 5’10” and 180 lbs.

That means half of those selected were bigger and taller than that, and the other half were smaller and lighter.

Deciding how big and lean YOU should be depends on four factors, including

1. Your current level of fitness
2. Your timeline to go to selection
3. Your current level of lean muscle mass

Why Size and Body Fat Percentage Matter

Before going step by step on how to determine where you’ll perform best, it’s worth understanding why size and body fat percentage are so important.

Candidates at SFAS with the most lean mass and lowest body fat percentage had 6 and 7 times higher odds of being selected than those with the least lean mass and highest body fat percentage.

And that same research also analyzed eight other predictors of selection success. 

1. Lean mass (Cohen’s d = 0.71)
2. Body fat percentage (d = 0.70)
3. Bone mineral density (d = 0.60)
4. Body mass (d = 0.40)
5. Fat mass (d = 0.39)
6. Bone mineral content (d = 0.37)
7. Height (d = 0.35)
8. Body mass index (d = 0.21)

Unsuprinslgy lean mass and body fat percentage top the list.

Recommendations for Special Forces

But even though lean mass is important, I DON’T recommend everybody to put on muscle, and I’ll explain why in a minute.

But there is one recommendation I will make to every person training for selection.

That is to find your high-performance body fat percentage.

If you’re 20% or higher, losing several pounds of body fat will make you run and ruck faster. But body fat is a double-edged sword. At both high and very low levels, it can make you feel slow and lethargic.

You need to find a healthy range to perform at a high level without experiencing hunger, low energy, or other deleterious effects.

Since side effects of low body fat kick in at different levels based on the person, I recommend you work your way down to 15% and see how you feel.

Your current level of fitness

Once you reach that healthy, lean range, you can express your fitness to its fullest potential – no longer will 10 or even 25 extra pounds of fat weigh you down on your 5-mile run.

So, you will be the fastest you’ve ever been.

But before you increase your calories and hit the gym, you need to do an honest assessment of your cardiovascular fitness. 

To keep the recommendations simple for this video, I’ll break it into three categories

1. Exceeding the standards
   1. If you’re running faster than a 38minute 5 mile
   2. And comfortably rucking 14min/mile pace or faster then you’d be in this category
2. At the standards
   1. 39 minute 5 mile
   2. Rucking just below 15min/mile pace
3. Below the standards

If you’re below the endurance standards and you’re lean, then I will rarely, if ever, recommend bulking.

Timeline to go to selection

But it gets more complex when we consider other factors, the first of the next two is your timeline for selection. 

Are you 3 or fewer months out, 4 – 6 months out, or 7+ months out? 

Where you are in your journey to selection is critical to informing how you prepare.

Fat-Free Mass Index

The other aspect of body composition is your fat-free mass index, which is basically BMI but accounts for muscle mass and is standardized for height.

Generally speaking, I like my athletes to have an FFMI of 21 or higher. But given timeline constraints, that’s not always possible. 

To help simplify your next steps, I’ve created this matrix to determine whether you should gain or maintain muscle based on your cardiovascular fitness, timeline to selection, and FFMI.

You can find an FFMI calculator here

But what’s the ideal size

But what if there were no timeline constraints, you had unlimited resources, recovery, and the ability to train.

Still, 15% body fat and 21+ FFMI are good guidelines.

I chose those numbers for two reasons, which serve the ultimate goal of getting selected and improving performance.

1. Low body fat percentage will allow you to run and ruck faster
2. High levels of lean muscle mass are a signal of strength. Having that muscle mass will make your logs, carries, and rucks far easier than if you were smaller and weaker.

Believe it or not, ¼ of all candidates who showed up to selection were at 25% or more body fat. Assuming they were of average build, those guys were carrying an additional pounds of fat mass.

It’s no surprise that only 13% of them were selected. 

The point is that body composition is one of the most powerful levers you can pull to optimize your performance, and it’s entirely within your control.

Common rebuttals

But I know there are still going to be those of you who reject the statistics entirely and explain how your cross-country running marine friend was selected at 150 lbs.

And then there will be guys who ask whether he should delay his ship to date to gain one more pound of muscle to hit an FFMI of 21.

Both of these people are missing the point.

If you want to be successful, it’s true; no amount of research or education will replace good old-fashioned hard work. But at the same time, if you’re spending 8 hours training per week, you want to make sure you focus on what matters most. 

Once you’re prepared, don’t hesitate. Sign your contract and train, eat, and sleep every day in a manner that you know you did everything in your power to prepare.

Your next steps

To make it crystal clear, here are your action items

1. Create a roadmap to achieve around 15% body fat
2. Assess your cardiovascular fitness
3. Plan a timeline to enlist/go to selection
4. Determine your FFMI
5. Use the table to determine your next steps

I assume you’re already on a regimented training program. To learn the smartest way to train for selection, check out this article.