Will The Real HIT Please Stand Up?

If you’re a regular reader of this web site or if you know who Arthur Jones, Mike Mentzer, and Ellington Darden are nothing that follows will be news to you. This is for the people who keep misusing the term “high intensity training” to refer to things like sprint interval training and various faddish infomercial exercise programs. Whenever you come across one, please share this with them and hopefully it can help reduce confusion over what HIT is and is not.

The term “high intensity training” was coined by Ellington Darden, PhD, during a presentation at Duke University in 1975 to describe the Nautilus training principles:

  • Intensity – train with a high level of effort, performing each exercise to the point of momentary muscular failure
  • Progression – gradually increase the resistance you use as you get stronger and better conditioned
  • Form – always maintain strict form to more efficiently load the targeted muscles and minimize risk of injury
  • Duration – keep your workouts brief to avoid overtraining, perform only one set per exercise
  • Frequency – allow adequate time for recovery and adaptation between workouts, training no more than three non-consecutive days per week
  • Order – as a general rule perform exercises in order of the sizes of the muscle groups worked, from largest to smallest

In What Is High Intensity Training? I describe HIT as “…a form of progressive resistance exercise characterized by a high level of effort and relatively brief and infrequent workouts, as opposed to typical training methods involving low to moderate levels of effort and longer, more frequent workouts.”

Ellington Darden, Drew Baye, Jim Flanagan

Drew Baye with experts on real HIT, Ellington Darden, PhD (left) and Jim Flanagan (right)

Unfortunately, the term “high intensity training” is vague enough it can apply to almost anything done with a high level of effort including non-exercise activities. “High” is relative, “intensity” is usually incorrectly defined by others talking about exercise, and “training” can mean teaching, learning, or practicing a variety of skills and behaviors. Because of this vagueness, people currently use “HIT” to describe everything from sprint interval training to various resistance training programs done at a relatively fast pace.

If “high intensity training” is so vague, why does it matter how we use it? Because to effectively communicate it is necessary for terms to have specific, agreed upon meanings. If a word can mean anything it might as well mean nothing.

Additionally, a big problem is people getting injured doing other programs and incorrectly claiming they got hurt doing HIT. Having ignorant trainers out there teaching unscientific and often downright stupid exercise methods and programs and calling it HIT reflects negatively on those of us practicing and teaching real HIT (unfortunately, the same goes for many trainers and organizations who practice and teach real HIT very poorly, but I’ll write about that some other time).

While the term is vague, Ellington Darden set the precedent for its use in the context of exercise to refer to the kind of hard, brief, infrequent exercise described by the Nautilus training principles, and it has generally been used in that manner for almost four decades now.

If you’re performing max effort sprints (running, cycling, rowing, swimming, etc.) you are doing sprint interval training, not high intensity training. It shouldn’t even be called “high intensity interval training” or HIIT since the terms are too similar.

Unless you are performing proper exercises (with positioning and movements based on principles of efficient muscular loading) to momentary muscular failure (real high intensity) in strict form (with a controlled speed of movement and smooth turnarounds while maintaining proper body positioning and/or alignment and path of movement) you are not doing HIT.

Stated differently, if you’re doing so-called “functional” movements (movements mimicking sport or vocational skills rather than designed around specific muscle and joint functions), not consistently training to momentary muscular failure (after the initial learning stage/break-in period and with a few other exceptions), or doing your exercises in a fast, jerky manner emphasizing quantity of work over quality, you might be working hard, but you are not doing HIT.

CrossFit and its clones are not high intensity training. P90X, Insanity, and similar programs are not HIT. Those people jumping around, doing sloppy calisthenics, and sprinting in the park and calling it “boot camp” are not doing HIT. The majority of programs claiming to be high intensity training are not HIT. Regardless of what you’re calling it, unless your exercise program is based on the Nautilus training principles outlined above you are not doing or teaching HIT.

Join the discussion or ask questions about this post in the HIT List forum

Like it? Share it!

Comments on this entry are closed.

  • Wade Gwin Jun 24, 2013 @ 17:44

    Amen. lol “jumping around… calling it ‘boot camp’…” I lost it! ;D

  • Steven Turner Jun 24, 2013 @ 18:13

    Hi Drew,

    What puzzles me is that all this so-called HIT trainers have clients doing all sorts of stupid and dangerous activities in the name of health and fitness and every time a new and dangerous stupid fitness fad comes along they move to that. But when you show them “real” high intensity training (safe, efficient and effective) as outlined by Ellington Darden they call that “bullshit” training so to speak.

    What also concerns me is that “finally” research shows that “aerobic” “steady state” style training (Arthur Jones said many years ago) is inefficient and now that HIT is most effective. So what do all these idiots do introduce/produce more forms of high impact and ballistic movements for their unsuspecting clients.

    Not sure what can be done as the fitness industry has been following every dangerous fad for decades – trying to educate morons is difficult especially with all the realitity TV shows such as the Biggest Loser. These so-called expert trainers should be kicked out of the industry but all to often they are held up as “celebrated” fitness experts. These so-called experts have no idea what is meant by Nautilus “high intensity training” principles.

    One of our celebrity Biggest loser trainers started writing for a national newspaper he was going to turn Australian’s fitness and health around with the latest in fitness, push ups, clean and press, more high impact and ballistic movements all earth shattering new training techniques. Nothing about inroading, orderly and sequential fibre recruitment, MMF, or what Ellington Darden wrote nearly four decades ago.

    • Drew Baye Jun 24, 2013 @ 19:11

      Steven,

      I think science fiction author Robert A Heinlein best summed up the problem when he wrote “Most people can’t think, most of the remainder won’t think, the small fraction who do think mostly can’t do it very well. The extremely tiny fraction who think regularly, accurately, creatively, and without self-delusion – in the long run these are the only people who count…”

      When it comes down to it, real HIT is what you get when you apply science to the problem of how to exercise effectively, efficiently, and safely. The problem is the majority of people don’t understand science and couldn’t be bothered to do the necessary research or thinking required to separate fact from fiction so they abdicate judgement to so-called “experts” who often suffer from the same lack of understanding but are savvy marketers.

  • Craig Jun 24, 2013 @ 22:24

    Even after excluding all the things that clearly don’t fit the original notion of HIT, it does seem like there is still a very large range of strength training approaches that fall under the umbrella of HIT.

    At one extreme, you have people doing a big 3 every 14 days, and barely breaking a sweat cause the whole routine is done in 7 minutes. (“You can do it in your street clothes – no need to shower!”). At the other end, you have the original nautilus circuit – 10 to 12 exercises done 3 times a week. And off in the distant past are those legendary AJ circuits where he stacked up multiple exercises for the same body part (e.g., leg extension, leg press, squats), all taken to failure & rushing between sets with the effect being to put the trainee in a condition of shock, and nausea. (Wonder what Jones would have thought of the CrossFit mascot Pukie?)

    So even though I am aware of the opinions of Jones, Darden, Mentzer, McGuff, Hutchins, Little, etc., I still occasionally feel like asking: Will the real HIT training method please stand up & indentify yourself?

    • Drew Baye Jun 25, 2013 @ 9:34

      Craig,

      High Intensity Training is a set of principles to be applied based on individual goals and response to exercise, rather than a specific program or workout routine. Since individual response to exercise and goals varies considerably, so do the ways the principles can be applied. Nautilus Training, Heavy Duty, SuperSlow, Static Contraction Training, etc. are all real HIT. They are all based on the same principles, they just vary in their specific application of them.

      Arthur has spoken and written critically of a lot of the things which are now part of CrossFit, and would have thought it was stupid.

    • marklloyd Jun 27, 2013 @ 15:52

      Big 3 every 14 days or 10 exercises 3x a week; all part of the same idea. (“No sweat” ‘s due to low room temp & many -well-directed fans, not literally no sweat.) Within the last 2 years, (same trainer, same facility,) I’ve gone from “the other end” to my current Big 3,(pulldown, chest press, leg press), every 14 days, (with an alternate week of lumbar extension, L&R torso twist, & crunch, to leave the limbs alone all 14 days). The change happened gradually, an exercise less here, an extra day off there, only when progress stalled, & only kept in place if progress resumed. The result: at age 64, I’ve become stronger, (& appear to be leaner), almost every workout for those 2 years. I see no conflict.

  • Bob Jun 25, 2013 @ 6:08

    Hi Drew,

    Thanks for clearing that up, I have noticed that everybody has been using that term, it is good to know the history.

    Since you brought up sprint interval training, what are thoughts. They seem like they could be a good companion to HIT. Which leads me to another question. Beyond diet, sleep etc. and HIT once a week or so, what other training would you recommend. It seems that something similiar to Kelly Starret’s protocol of about 10-15 min per day spent on mobilization could be beneficial. I don’t recall mention of this in your book, my apologies if I missed it.

    I don’t want to seem greedy, so please just think of these questions as suggestions for future blog posts. Thanks.

    • Drew Baye Jun 25, 2013 @ 9:58

      Bob,

      High Intensity Training will provide the same or better cardiovascular and metabolic conditioning more safely than sprint interval training. While there may be some strengthening benefit to stretching post-workout (a few studies by Westcott suggest this), and people who require increased flexibility would benefit from daily stretching, very few muscles can actually be stretched and nothing fancy is required.

  • ad ligtvoet Jun 25, 2013 @ 6:40

    HinDrew,
    Great article again.
    Certainly indeed for those not so long around,so they won’t be sucked in by popular terms and start doing stupid things.
    After being 30+ years in the exercise field and about 20 years concerned with HIT I can only conclude that despite all the good work done by you and all the others the exercise field is still running backwards.I know that we never will influence the majority but for those we do influence we should indeed provide the best service possible.
    In that light I made it a pollicy to only spent time on those that show honest interest and not waste time on those that like the hype.
    Btw.why are you sitting on your knees on that picture???
    I have met Ellington once so I know his height.That means you are short of posture,probably(as seen on other pictures) short legs. On the other hand,Jim must be huge.
    best wishes,
    ad

    • Drew Baye Jun 25, 2013 @ 10:06

      Ad,

      Jim Flanagan is huge. He’s 6’5″ and about 260 pounds. Ell is about 5’11”. I’m only 5’8″ so I look pretty short standing between them.

  • Thomas Jun 25, 2013 @ 12:16

    Drew,

    This reminds me of Ken Hutchins attempt to define exercise, which I think was genius (although difficult to sell to the uninformed). Also, I’ve noticed a trend in calling ANY kind of interval training “Tabata”, which is a total and complete joke. I’d like to see any of these gym goers do the a Tabata protocol and talk so lovingly about it.

    • Drew Baye Jun 25, 2013 @ 13:12

      Thomas,

      Ken’s definition of exercise is probably the best, although I disagree with the requirement for a clinically-controlled environment. While exercise in a clinically-controlled environment is optimal, it is no more necessary for exercise than having a particular type or brand of equipment.

      Like high intensity training, most people who think they’re doing Tabata would probably be unpleasantly surprised at the difficulty if they attempted the real thing; a few minute moderate-effort warm up followed by eight maximum effort twenty-second sprints with only ten seconds of rest in between, followed by a few minute moderate-effort cool down.

  • Steven Turner Jun 25, 2013 @ 21:50

    Hi Drew,

    Thanks for the reply above.

    If we go back to A.V. Hill in the early 1900’s he researched “steady-state” activities specifically running. Physiologically the HR V02 max would increase until they attained a steady state. I think that what most people do is take steady state activities and try to make it a non steady state activity (high intensity activities). The only way they can do this is to introduce high force, repetitive and ballistic type movements into the exercise program for example, walking, jogging, running, sprinting. Whilst you may increase the level of intensity of steady state activities to a certain point you than also greatly increase the risk of injury.

    From what I have read Arthur Jones realised that large amounts of steady state activities were potentially dangerous for injuries. Arthur stated, in article “The Real Value of Exercise”, “Running provides resistance, – jumping provides resistance. Any sort of muscle powered movement is met by some type of resistance – air resistance, water resistance, gravity, friction, or some other type of resistance. All that weight training does is CONTROL such resistance – making it possible to apply the resisatance where it is needed.

    Then you also have another problem with weight training, as Arthur goes onto say that, “millions of trainees continue to use routines that are of little or no value. thus most of the potential value of weight training – the real value of weight training is never realised”.

  • John Beynor Jun 26, 2013 @ 11:09

    Hi Drew,

    In applying TSC, If I can only do one or two stages of 20-30 sec., but not three with only say a perceived force output of 25-50%, is that fine? I’ve been experimenting for a long time now using both dynamic bodyweight and TSC, but I keep aggravating a chronic inflammatory condition and a neck injury. For many years I’ve been avoiding medication, but can’t get away from expensive weekly chiropractic treatments for years.

    Thanks, John

    • Drew Baye Jun 26, 2013 @ 11:16

      John,

      When performing TSC for an injured area you should not contract so hard that it causes pain during the exercise or causes the injury to act up afterwards. During the last stage you should only contract as hard as you think you can safely, and modify this based on how your body responds afterwards.

  • Daniel Bastida Jun 27, 2013 @ 17:18

    Notwithstanding ghost in the machine suppositions, muscle is bound by the same laws of nature as other natural phenomenon such as luminosity of stars, magnitude of earthquakes, luminosity of light bulbs, etc. Skeletal muscle has the ability to sustain long periods of low force out-put or short periods of high force out-put. In order to do one it must sacrifice the other. And it does so in a roughly logarithmic relationship.

    Muscular force out-put is at its highest when contracting isometrically and is capable of near maximum force out-put at very low velocities viz. the force-velocity relationship. As one continues contraction in either an extremely slow or isometric fashion, he will exhaust the muscles only capable of low force out-puts very quickly and require the use of muscle fibers capable of higher force out-puts. If he does not allow the recovery of muscle fibers responsible for lower degrees of force out-put, he will exhaust the higher order muscle fibers and, therefore, the totality of his musculature exponentially more quickly than would other-wise be done if he were to decease his force out-put even marginally (20% for example). The reason being is that if you only expose your muscles to loads that lower order muscle fibers can handle, they will be capable of prolonged contraction and rapid recovery even upon brief opportunities of respite.

    If one limits his muscular level of exertion even to intermediate order muscle fibers as with Cross-fit or HIIT one will be capable of orders of magnitude more volume, frequency and duration of mechanical loading.

    The major folly with Cross-fit and other exercise modalities is their fallacious usage of the word “intensity”. Cross-fit trainers use intensity to mean mechanical work over a given period of time [(reps x weight)/(time)]. This often includes increasing weight and reps and/or reducing the amount of time per set of the same amount of weight and reps. The problem with this is that it is a measure of power in the physical sense (work or energy per unit of time) rather than intensity (power per unit of area or volume). If one only effectively loads low/intermediate-order muscle fibers, then he can continue loading them almost indefinitely so long as he rests long enough between each, which is likely only several minutes. A Cross-fitter is likely to simply have his body worn out due to overall energy expenditure rather than from muscular intensity output and fatigue.

    Recall that in order to engage muscle in the most meaningful way, it must be done when velocities are either extremely low or non-existent. High degrees of force out-put compelled by muscular effort must be done absent of any outside forces in order to truly measure intensity. This requires un-interrupted loading done by isometric contraction or very slow movement in order to compel the higher-order muscle fibers to power movement of a given resistance. Cross-fit merely observes the final result of the set (weight x reps/time) but ignores the mechanism by which this is achieved. An intense set of exercise may occur towards the very end of a set if the subject is so exhausted that he absolutely must utilize only his muscle fibers because the rest of his body is too trashed to jerk, sling, throw, or bounce the resistance to off-load the muscles. This would be an inadvertent and haphazard effect of such an exercise modality.

    So not only is the definition of intensity given by Cross-fitters and HIIT trainers wrong in that they are really referring to power, they don’t consider that it is not skeletal muscle that is powering the movement of the resistance in an uninterrupted fashion. Momentum, variations in moment arm, economy of motion, bouncing resistance onto bone, ligamentous, and tendinous tissues all contribute to a decrease in muscular intensity. If you are not utilizing an exercise protocol in order to improve the function of the only tissue that is capable of directly compelling movement, then you are at best improving a skill with mainly negligible harmful effects (swimming) or are abusing the other tissues in your body (Cross-fit).

    Intensity = power/volume. If we are after exercise intensity, which is really muscular intensity, then we are after force out-put per unit of time(power) relative to a certain surface area or volume of tissue (muscle tissue). This can be measured in resistance per unit of cross-sectional area (CSA) or unit of volume (cm^3) of muscle tissue assuming that it is known unambiguously that it is only the muscle tissue that is producing the force required to move and/or hold the resistance relative to what it is maximally capable of.

    Unfortunately, the most reliable metric we have now to measure muscular intensity is volitional effort diverted towards mechanical work with muscle, which is very subjective and lacks quantifiability. “Real HIT” is, therefore, by its nature far more of a qualitative form of exercise.

    • Drew Baye Jun 27, 2013 @ 22:34

      Daniel,

      CrossFit gets so much wrong. I addressed a lot of this in https://www.baye.com/crossfit/

      • Daniel Bastida Jun 27, 2013 @ 23:37

        Oh, man.

        My post was a TL;DR as it was. I am sure that a “Cross-fit is Criminal” movie series could last Spielberg the rest of his days.

        It was all I could do to condense my points as I did when criticizing Cross-fit on their erroneous definition of intensity in a purely scientifically conventional sense.

        Fortunately, most people drawn towards HIT and most clients who solicit HIT facilities are analytical and/or scientifically-minded. This makes it relatively easy to explain fairly complex topics. It is a pretty elegant selection process.

  • carlos Jul 3, 2013 @ 15:08

    Man, this article should be attached to every wall in every regular gym AROUND THE WORLD GIANT SIZE!

  • Ondrej Jul 5, 2013 @ 7:52

    Drew,
    did you expriment with Zone Training/J-reps? I find it interesting option for basic equipment that might increase hypertrophy, I never tried it though. It’s also hard to find any complete info on this method. It’s focus on feeling/pump reminds me of focus on muscles, squeezing technique etc. But it seems like trainees without strict HIT form could benefit from Jreps.

    • Drew Baye Jul 5, 2013 @ 10:19

      Ondrej,

      Trainees without strict form should focus on improving their form rather than messing around with gimmicky repetition methods.

      I wrote the following about J-Reps on Ell Darden’s forum back in 2006. Johnston attempted to counter, but had nothing but more of the same unsupported claims and hype and challenged me to debate him on it in his publication but did not want to continue in a public forum.

      I would change some of the wording I used when I wrote this, replacing “load” with “resistance” (the product of load, lever, and other factors) and in number 1. in the conclusion replace “load” with “intensity”. J-reps is best categorized as a set extender rather than an intensifier because it increases the duration of work rather than the relative effort.

      From 08/07/06:

      “The idea that one can improve the effectiveness of an exercise by dividing the ROM into zones and performing partial movements in those zones in order from hardest to easiest overlooks the fact that while this may make each zone feel equally hard, the actual resistance encountered in each zone does not change.

      What matters is the load, and if the load is insufficient in part of the ROM, it would be more practical to find a more appropriate exercise or machine or perform a partial rep over the portion range where a meaningful load is encountered.

      The idea is to make the exercise harder, not simply to make it feel harder. The two are not the same.

      I have been looking, and am unable to find research other than the study from MedX and comments in Arthur’s writings about strength gains being position specific. Considering that test performance, even isometric, is somewhat skill dependent, and that strength is only one factor in performance, I’d need to see more research to have much confidence in this. If hypertrophy is the goal, rather than improved performance on a specific type of strength test, full range movement isn’t necessary. Some movement, but not necessarily full range.

      Bill de Simone and John Little have both put forth strong arguments in support of this. See Moment Arm Exercise by Bill de Simone, and the Max Contraction books by John Little.

      Claims that such rep methods are effective due to increased pump are not supported by research. I am not aware of any studies showing pump to be a significant factor in hypertrophy stimulation, but I am aware of studies showing the opposite, that blood flow restriction may enhance the stimulus for hypertrophy during exercise.

      In conclusion:

      1. The stimulus for hypertrophy is strongly correlated with load. Making part of an exercise FEEL heavier by fatiguing the involved muscles doesn’t actually make the load higher, or make doing the exercise in the lighter portion of the ROM more effective. Stage reps does not solve the problem of insufficient load.

      So, find a better tool, or if possible alter the performance of the exercise to make the resistance and strength curves more congruent.

      2. Some range of motion is necessary for hypertrophy (negative motion, in particular is strongly associated with cellular signaling for hypertrophy), but a full range of motion is not. Too many people have made significant gains with partial reps and methods like Power Factor Training and Bill de Simone’s Moment Arm Exercise to dismiss this.

      So, if you can’t find a better tool or alter the performance of the exercise to make the resistance and strength curves more congruent, perform the exercise only over the range where a meaningful load is encountered. If you want to cover the full range, alternate between exercises who’s resistance curves provide meaningful load in different portions of the ROM, such as dumbbell pullovers ( first half of the ROM) and straight armed cable pullovers (second half of the ROM).

      3. A nice pump might feel good and make you look bigger and more vascular momentarily, but alone is not an indication of effective exercise or a significant factor in stimulating hypertrophy. It is possible to become very pumped without having an effective workout, and to have a very effective workout without much of a pump.

      So, if you like being pumped up, fine, but don’t evaluate your workouts based on pump.

      • Donnie Hunt Jul 5, 2013 @ 23:33

        I had wanted to ask you your thoughts about J-Reps and stage reps Drew. I think you answered my question in point #2. Thank you.

  • Ondrej Jul 8, 2013 @ 4:22

    Thanks. Part of the game is knowing you do the best thing for your goal and I am pretty sure I do. Sometimes it’s easy to forget how much effort you put into refining your recommendations, because they look so simple. One has to be really careful not to become armchair training expert, or high volume solution seeker. It’s all just procrastination.

    • Drew Baye Jul 8, 2013 @ 9:32

      Ondrej,

      Some times the hardest part is making things simple. While the science behind it can get pretty complex, the application of it shouldn’t be.

  • Ben Tucker Jul 31, 2013 @ 11:45

    Why does it seem natural to imagine Flanagan with a battle axe, a helmet with horns and a braided beard in that pic?

    The dude is an ox of a man.

    • Drew Baye Aug 2, 2013 @ 9:18

      Ben,

      Jim is a big, strong guy. Although, considering the name Flanagan has Irish origins, I would imagine a kilt would suit him better than the stereotypical (but historically inaccurate) horned viking helmet 🙂

      • Ben Tucker Aug 2, 2013 @ 17:14

        Too true.
        I was thinking Middle Earth, but that works , too;)

  • David Aug 6, 2013 @ 9:45

    Hi Drew.

    I am trying to asses whether the machines in my gym takes into account the changing muscletorque during the excersize-movement. Can you recommend a good read about the changing torque and force output of the single joint leg extension muscles (and other excersizes as well)

    Best regards David.

    • Drew Baye Aug 6, 2013 @ 10:13

      David,

      Arthur Jones writes about this in his Nautilus Bulletins. A practical way to assess the resistance curve would be to perform a few very slow repetitions with a moderate weight and paying close attention to the resistance over the full range of the exercise. Assuming you are positioned properly and performing the exercise correctly, if you can feel a noticeable change in resistance at any point in the range of motion then it is not well balanced to your strength curve.

  • David Aug 7, 2013 @ 4:15

    Thanks Drew. I have read the bulletins but would like more information.

  • Ray Jul 7, 2014 @ 13:40

    Drew, this is old and likely won’t be answered, but Clarence Bass uses HIT but he cycles his reps from 20 to 12 to 8 over four week periods each. I guess you could call it periodization. It obviously works as pictures of him in his 70s attest. What are your thought on periodization? Thanks, Ray

    • Drew Baye Jul 7, 2014 @ 14:12

      Ray,

      To paraphrase Arthur Jones, the fact that some method produced some result is not proof the same or better results could not have been achieved with another method. Periodization is no more effective for improving strength and size than training with a consistent repetition range, and may be less effective because people tend to respond best to a particular repetition range, and increasing or decreasing it arbitrarily would move them away from what is optimal for them. I discuss finding your optimal repetition range in the new High Intensity Workouts.

  • Hernani Feb 12, 2015 @ 22:37

    Hi Drew

    I’m trying to apply some HIT training, but not with much success. Hope you can give me some hints.

    See, I’ve been using intense workouts and paleo diet for some time. Had some good results in the beginning, lost fat, gained muscle, but I seem to have reached a stagnation point.

    My workout consists of a series of 8 compound movements done in sequence with no rest between them. Medium weight, many reps (not so fast though) until failure. I do usually 2 round 2x a week.

    Recently I read Body by Science. Really impressive book! Started Doug’s big 5 workout routine, with super slow movement, for like a month or so. The results didn’t go very well. I started gaining some fat and observed my muscle tonus slightly decreasing.
    What am I doing wrong?

    Thanks

    • Drew Baye Mar 4, 2015 @ 10:40

      Hey Hernani,

      You shouldn’t have a reduction in muscle tone after a month even if you stopped training completely. I’ve had clients leave for a month or two for work or vacation and come back just as strong and with no loss of muscle. If you’re gaining fat, you’re eating too much. The reduction in volume would have made a slight difference in energy expenditure, but not enough to result in noticeable fat gain in such a short time frame. I recommend reading High Intensity Workouts, as this goes into significant detail about how to adjust the volume and frequency of your workouts, repetition ranges, etc. based on your body’s response to exercise to optimize results. If you need more specific help after that, I’m available for consultations.