Controversial: Bulk Up or Slim Down?

Introducing the new “Controversial:” series.  Occasionally, I’ll be exploring different questions that have plagued thru-hikers for quite some time.  The goal is to look at objective evidence and let readers decide for themselves what they’d like to believe.  Let me know what your approach is in the comments.

Dynamic Weight

It’s no secret that weight is a key factor in athletic performance.  We’ve all heard crazy tales of wrestlers foregoing drinking water for 12 hours at a time in order to make weight for their match.  Epic stories of football linemen consuming massive amounts of calories in the weeks leading up to a big game in the hope of adding a few more pounds.  Undoubtedly, adapting your body to fit the needs and demands of an upcoming event is a good strategy.

That’s great and all for games and sports ball, but what about when the thing you’re preparing for is an effort that will last for months?  I was talking to another fellow future attempter of a calendar year Triple Crown recently, and while I’m busy trying to shed a few excess pounds, he’s busy trying to gain 15 before he begins hiking.  Both of these strategies cannot be correct, or can they? Let’s look at the arguments for each.

Slimming Down

Let’s face it. Gearheads continually stress about the ounces within their packs.  Logically, it should follow that losing excess weight off of the body would be of just as much importance. Your bank account would be happier as this is much easier on the wallet as well.  One does not need to purchase a $400 Dyneema fabric tent to shed four ounces off their body. Physically training for a thru-hike should model whatever plan we have for the hike itself.  More often than not, this involves some form of cardio as we train our lungs and heart to handle the stresses of climbing mountains with a backpack. The funny thing about cardio training is that it generally destroys any excess muscle mass.  Not just muscle is lost though, but also fat, resulting in beneficial weight loss.

Taking this approach generally results in a lower body fat percentage prior to beginning a long-distance hike, and has the possibility to result in more miles per day covered as well as less fatigue.  I should pause here and warn you that there is an important caveat here.  Having a lower body fat percentage or less muscle on the body means the body has less fuel readily stored. You have fewer reserves for those times where you’re running on empty.  This means that, unfortunately, you’re more susceptible to malnutrition on the trail, and you’ll more than likely need to keep a keen eye on your daily calorie intake while hiking.

I was sucking wind as I crested this pass; definitely could have benefited from some prior conditioning!

Bulking Up

On the other side of the coin, there is certainly an argument to be made for adding some weight to your frame.  Especially before finding yourself at a terminus of any trail.  Adding beneficial weight can have a significant impact when it comes to on-trail performance. What is beneficial weight you may be asking? The answer is simple: useful muscle mass.

Quite simply, there is almost no foreseen beneficial outcome that can be associated with adding fat of any capacity unless otherwise directed by a medical professional.  Muscle mass that is added prior to a hike should be directly related to hiking itself. Sorry to those who fantasize about having a shredded upper body, but leg day would be more beneficial to you.  Having stronger legs will help when you add significant weight to your body in the form of a pack and are expected to maintain some serious miles. If you can add some muscles here and there, chances are you’ll find yourself with a  greater power-to-weight ratio. This translates to less skinny (weaker) legs slogging up switchbacks, and more thunder (stronger) thighs gliding over mountain passes with ease.

Decisions, Decisions, Decisions!

Unfortunately, it’s near impossible to add beneficial muscle mass while simultaneously cutting the fat off the body.  Glancing at professional bodybuilders’ routines, one can clearly glean that they add weight in the form of both muscle and fat.  Following this, they then extensively focus on losing the aforementioned fat in the next phase. Ideally, we might train for a thru-hike in this manner.  Months leading up to the hike, it may be beneficial to focus on either strength or endurance exclusively.  However, also choosing then to switch over to the other as the start date gets closer. 

So then, what’s your take?  How will you be preparing for your upcoming thru-hike?  Let me know in the comments below.

*Disclaimer; by no means am I a trained nutritionist.  That being said, I’m fairly adept at researching and have several peer-reviewed articles incorporated into this post.  Message me on Instagram if you’d like to have a peek at my references.

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Comments 3

  • Scott Hoyland : Oct 22nd

    I can’t say what the best thru hiking body composition is, because I haven’t been on a thru hike before. However, I disagree with your conclusion that it’s near impossible to add beneficial muscle and lose fat. While your reference to bodybuilders’ technique of bulking and cutting is common, that does not mean it is the best strategy for the thru hiker. The human body prefers carbohydrates, then fat, and finally protein as an energy source. Muscle can be retained (or even increased) by including a strength training routine and consuming enough protein. It is important to remember that every person is different in regards to nutritional needs and some trial and error is required for best results.

    Secondary source (contains links to primary sources):
    Tertiary source: Personal experience training for a marathon going from 192lbs 25% body fat to 175lbs and 14.5% body fat with lean mass increasing from 144 lbs to 150lbs through a combination of diet, weight training, and cardio.

    • Zach Terpstra : Oct 22nd

      Hey Scott!
      I’d have to agree with you by highlighting the importance that everyone’s body is different. In regards to my phrasing, you’re right and I was wrong. I suppose I should clarify my phrasing. While it is certainly possible to gain muscle while simultaneously losing fat it is not nearly as efficient to take this approach if your desired outcome is one or the other. Thanks for the insight and congrats on the marathon man!

  • Rick Antle : Oct 31st

    I’d like to offer another view of a way of eating that will promote muscle gain, fat loss, and energy maintenance. First, the body does not prefer carbohydrates. It’s true that in general the body will metabolize carbohydrates faster than other sources, but the down side of that is the roller coaster of high and low blood sugar which drives hunger. And if we are counting calories (which is the wrong way to place value on food) carbohydrates offer 4 calories per gram consumed, while fat provides 9 calories per gram… so why shave grams from your pack if your only going to put the weight back in with a calorie light food source that provides no nutritional value and is detrimental to our heart and circulatory system. Given the chance the body will feed it’s cells the same glucose from fat (gluconeogenesis) as from carbohydrates. Also, the body’s metabolizing of fat levels out the blood sugar roller coaster giving you a more stable energy level while eating less. So, a diet of low carbohydrates, relatively high fat, and sufficient protein is the right dietary balance to sustain one through a 12-20 mile day. The excuse that crap food is the only food source available on the trail may have some merit, but that doesn’t make it the right food source. And just because the larger age population on the trail is young doesn’t mean that after decades of eating like that isn’t going to kill you or make you obese and kill you. Give up the sugar, eat some pepperoni if you’re on the trail, if you’re not on the trail eat green leafy vegetables, as good a quality of protein you can afford, and don’t be afraid of fat.


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