Of Sprinting, and Leptin Signaling Mimetics

My good friend Chris Highcock, of Conditioning Research, (and he by way of Andrew Badenoch, of Evolvify) clued me into the recent Journal of Applied Physiology article, Is sprint exercise a leptin signaling mimetic in human skeletal muscle?  

I won’t delve into the interesting details of this paper, as Chris has already done a wonderful job of that here, but I would like to add just a few of my own thoughts about these findings.

What’s more important, vis-a-vis, weight loss — diet or exercise?

I’ll get into this a bit more in a future post, but as a Physical Culture 2.0, new breed fitness educator, I am the interface between geeked-out science, empirical wisdom and a general public searching for accurate and articulate answers, to help them make sense of the never-ending, fire-hydrant-like gusher of (often times) conflicting diet and fitness “truths”.  Two big obstacles that I have to overcome in performing this function, though, are (1) that my answers are predicated upon a base understanding of a movement (Physical Culture 2.0), which itself requires the acceptance of there being no black-and-white answers — that in all instances, the notion of n=1 and “it depends” prevail, and (2) a general public which is too tired/stressed/overwhelmed with day-to-day life to undertake the due-diligence required for such an understanding; a general public who only has time for the ingestion of pat answers.  You see the conundrum here.  And I’ll get to why this matters in relation to this particular study in a moment, but for now let’s take a quick look at an extension of the above-mentioned study’s findings — the performance of fasted-state, High Intensity Interval Training.

Fasted HIIT (or, don’t let lack of scientific underpinnings spoil the empirical results)

Dan John has articulated as much in some of his prior writings, but let’s just say that you’ve followed a Paleo-like diet for 30 days (ala Robb Wolf, or Whole9), coupled that with adhering to a basic 5 x 5 weightlifting scheme and, lo-and-behold, at the end of that trial period you find yourself having dropped 30 lbs of fat and gained 5 lbs of muscle.  Now, did you lose that fat because you physically ingested fewer calories, or did that fat loss come as the result of a favorable hormonal cascade established by the diet and/or workout scheme itself?  Or what it some other combination thereof?  And hey, “everyone” knows that one cannot simultaneously lose fat and gain muscle, but your little experiment just proved the contrary.   And here’s the thing: do you really friggin’ care that you’re treading on shaky scientific ground?  Does lack of scientific confirmation negate your results?  Is the fact that you had to punch three new holes in your belt and that your shirts are now fitting tight across the shoulders (instead of across the gut) somehow now irrelevant?

I don’t bring this up so as to promote a Flat Earth Society mentality when it comes to matters of Physical Culture, but more so as to put some prospective on the weight afforded to the supporting science (or lack thereof, as the case may be) in this area of study.  In other words, empirical evidence means a hell of a lot to me.  Pondering the “whys” behind an empirically-proven methodology’s efficacy —  intellectually invigorating as it may be — ought not get in the way of actually utilizing that methodology in the real world.  I can always go back and tweak a methodology accordingly, depending upon the outcome of follow-on science.  That I cannot articulate precisely and unquestionably (as supported by science) what, at the cellular level, is precisely occurring as a consequence of HIIT training does not prevent me from utilizing this method of training or, more importantly, from reaping the benefits.  We’ve long known, in the strength and conditioning community, that performing HIIT in a fasted state just obliterates body fat even while precipitating lean muscle gain.  Of course, there was the ever-present chorus of “there’s just no relevant science to support that claim” who presumably sat this one out, waiting for scientific conformation one way or the other.  In the training of horses, though, as in the training of athletes, the proof is in the final product.  Can these methods be more finely tuned in light of prevailing science?  You bet.  Wait for the perfect answer, though, and you’ll never get under the bar or put spikes on the field.  In other words, get in the game, and don’t allow the perfect to get in the way of the good.

This sprint/leptin study is a good case-in-point to what I’m attempting to articulate in this post.  We know, empirically, that fasted HIIT works –

*note – I am extrapolating here, as this particular study only considered the performance of a single sprint on the resultant hormonal cascade.

– and now we see, presumably, one important (and no doubt interesting!) pathway in which this scenario plays out.  We also see that being fasted (at least carbohydrate fasted) is an important part of the overall equation, here (if weight loss is a mitigating factor), and so we can now tweak our methods accordingly, and rock on.

So what’s more important in weight management, diet or exercise? 

Asking a badly articulated/constructed question is worse than asking no question at all; the problem is that the person to whom the question is directed will feel an obligation to offer-up an answer, ham-strung as it may be.  Construct a question that legitimates a sound-bite answer and you’ll get exactly that (Poli-Sci/Stats 101).  You’ll also get an answer that only approximates the truth of the matter, if that.  Of what relevance is this to the sprint/leptin study?  Well, let’s consider how best to achieve a long-term fasted state to begin with, and still have the energy required to tackle a HIIT-like training session with adequate intensity.  The short answer here is that we’ll need to first establish an enzymatic and hormonal underpinning resultant of following a Paleo-like diet.   The blood-sugar roller-coaster resultant of a (for instance) Standard American Diet will throw a monkey wrench into the works from the get-go.  I see this play out all-too-frequently in real-world practice.  That far-far-away look in the middle of a HIIT throw-down?  Yeah, that’s blood-sugar crash, up close, ugly and personal, kiddos.  At the same time, though, we know that intense physical exercise potentates the expression of that same desirable enzymatic/hormonal underpinning.  So what we’re really talking about here, of course, is synergy.  Synergy is slippery, though, and not easily accounted for in a standardized-testing, sound-bite-answer world.  The masses want easily-digestible answers (especially if provided by Oz, Oprah, et al) and synergy simply doesn’t play in that house.  Sorry to disappoint, but there it is.  You can no more bust ass in the gym and on the field, eat crap and expect phenotypical perfection than you can eating as a Paleo purist while abstaining from (at least some modicum) of repeated, physical exertion.  And no, computer jockying does not count as “repeated physical exertion”.

Synergy, my friends; diet and exercise — it’s the one-two punch, and the only way I know, to attain phenotypical perfection.

Sunday’s MetCon circuit –

Being under a bit of a time crunch didn’t prevent me from sneaking this one in.  Short, sweet, and to the point.

– 10 second sprint

– 20 ft. rope climb

– 30 ft parallel bar hand-over walk

– 20 yd dual hops

– 5 muscle-ups

– 30 ft hand-over monkey bar traverse

– 7 tire flips (+ 5 extra on the last round)

wash, rinse, repeat x 3.

Trivia for the day – 26 tire flips = 51 yards (football field sideline to sideline) 🙂

In health,


16 responses to “Of Sprinting, and Leptin Signaling Mimetics

  1. Love the post.

    “I am the interface between geeked-out science, empirical wisdom and a general public searching for accurate and articulate answers, to help them make sense of the never-ending, fire-hydrant-like gusher of (often times) conflicting diet and fitness “truths”.”

    Very well stated and true! It would be great if we could access you like Captain Picard accesses the computer on Star Trek. After a HIIT session “Interface, Report!” A response is given a baritone Texas drawl.

    I agree analysis can sprout paralysis but to do the wrong exercise while searching for the correct methodology is a very tall order. I know you’re comparing good and perfect… but I can’t help but relate my own struggle working out in a globo gym for years thinking I was doing the right thing and coming up short on my diet and minimal strength goals until I got fed up and started HIIT on my own (scared to death). My girlfriends are very resistant to lifting heavy – they say it hurts or is not enough. They go back to the elliptical… Inertia – body at rest wants to stay at rest, a body in motion wants to stay in motion. That’s science too. 😉 And I raise these issues because I know they are not beneath you. This is why you and your blog Rock!

    Sidebar: How do you know the enzymatic cascade that happens with HIT? How do I find that out for myself? I know biochemistry, in general and this knowledge is for my own edification. Thanks Professor Norris!

  2. Quote:

    Of course, there was the ever-present chorus of “there’s just no relevant science to support that claim”

    A terrible misquote, but;” If the facts don’t fit the theory then I change my theory. What do you do?”

    You’ve nailed it, empirical evidence is evidence, theories are theories…..


    • I believe that was Einstein, no? When asked what would happen if the results from his eclipse experiment would not support the theory of general relativity? In any case, it’s a fantastic way to approach science.

  3. Love the article, and really hits close to home for me. I’m about a week away from taking my personal trainer certification, and in the meantime I started training a friend of mine just as a personal favor. A week ago she asked me just what percentage of fat loss was related to diet vs exercise, and at the time I couldn’t figure out just why the question bothered me so much.

    Reading your post I think I can fully appreciate why the question bothered me. In the first and foremost, it was a kind of double edged sword, because I didn’t want to provide a cop out for my own methodology by saying that weight loss is mostly diet and and you can’t out train a bad diet, because that excuses a lack of results from the workout. On the other hand, a blanket statement like “this type of training will be the dominant hormonal force and everything else takes a backseat” seems like a license to eat a crappy, SAD diet forever.

    And more than anything, your answer, as unsexy as it may be, is the true answer: you need both, and percentages are absolutely bullshit. How can anyone say what the percentage of fat loss is attributed to diet and what is attributed to exercise?

    In the end unfortunately when it comes to isolating work outs, all you can really measure are fitness and strength standards, not what percentage of fat cells were oxidized during sprinting vs what percentage was oxidized due to your diet.

    The big problem is really your point that bad questions demand even worse soundbites to answer them. It would be wonderful if I could say something like this to everyone who wanted to get something worthwhile from a workout plan:

    ” Look, simply working out to burn calories is not only inefficient and chronically stressful, it doesn’t require any sort of supervision on my part as a skilled trainer. My goal is to lay a foundation of strength and muscular fitness that will afford you a better hormonal regulation of insulin, leptin, and glucose and keep you from falling to dust in the coming decades. In keeping with these goals, you should really change your diet as that will absolutely turbocharge the results you would get from these workouts, both physically and from a simple long term health perspective. And if down the line you want to really burn serious calories during a workout, you will need to be in shape to do that, and right now you probably aren’t in shape to do any sort of efficient form of metabolic conditioning, which is why we start with strength and muscle as the goal.”

    That’s a bit long winded though, no?

  4. @VartanK: I Iike your blurb. If you’re speaking to a female, I’d add something encouraging about all body types being attractive without sounding “be the best you…” Throw in a little locker room-gained knowledge for the ladies. It will help keep a smile on their faces when the booty and legs of their jeans are tight from heavy squats and sprints (but the waist is loose). Men don’t seem to mind the tight pants. Just my two cents.

  5. I actually relate really well to women because I’m super short and have what can only be described as a “ghetto booty”, so I do always tell them “look, I lost 30 pounds, went down 4 pant sizes, and still haven’t lost my ass, so don’t worry”. One thing I have learned is every girl has the twin fear of gaining too much muscle, but also losing too much fat around the “asset” areas;-)

    And thanks for the encouragement Keith, I think I might just man up and go with that answer, and just adjust it to fit personality types along the way, because I don’t want to bail out or lie to anyone.

  6. A question about SSTF. On paper, SSTF seems to more or less address all necessary stimulus required to achieve global conditioning, i very often observe that people following SSTF are always wiry, including me. They do not carry the same hard muscular look that people who follow a reasonable multiple set yet low volume routine like the basic Starting Strength program, that is still low volume. I have personally experienced that whenever i switch back to a multiple set low volume program, i seem to start looking thicker(more muscular), but again going back to SSTF due to the “science” that supports it, I start looking wiry. Why?

    • Ahhh, the 10-million dollar question, Karthik! 🙂 I’m not sure anyone knows exactly why, but we know, from empirical observation, that it is. I think one contributing factor is that SSTF is usually performed with a full range-of-motion movement, with “failure” occurring at one particular spot in that movement. If all fibers contribute equally in a full ROM contraction, then all would be well — I don’t believe that is the case, however. This means that even though “failure” has occurred in that 1st set, there are still some fibers remaining (that are more active in other portions of the movement) that are still relatively fresh. Training in zones might be the work-around here; something that I’m experimenting with now, and something I’ll post about in the future.

      • So, how do we as trainers be sure about the best balance, between the most efficient(SSTF) and the most productive way to train our clients and ourselves. Are we going to J-reps again? Probably one of the most under utilized protocols, but definitely in line with your thought of recruiting maximum fibers.


        • I personally think it’s possible to really “have it all”, although I may be wrong on this. But one thing I really love about some of the work outs written by Christian T over at tnation is he finds ingenious ways to move through entire energy systems.

          For example, you can do a 6 exercise complex of 2-3 reps each exercise,with no rest, which comprises a circuit that you repeat 7 times. To me that is an excellent balance between traditional strength training, fatigue accumulating hypertrophy, and conditioning.

          I think truly the most underrated technique in hypertrophy training today is to also to take traditional Russian strength training routines and simply reduce the rest times to even less than traditional bodybuilding, allowing a full spectrum of muscle fatigue with significant strength gains and conditioning the body to recover quicker and quicker.

  7. Nice article but the science is worked out just not well known. I write about leptin and body comp all the time. My leptin rx and FAQ go over the details but if you want details come click the leptin tag and be prepared for serious science

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