Wednesday, December 21, 2016

Not Making Progress? New RCT: 'Personal Training' Sheds Twice as Much Body Fat and Quadruples Muscle Gains...

Certainly not a photo from the study.
I have to admit that I have never even remotely thought about hiring a personal trainer or coach. A mistake? Well, unlike the lives of the obese subjects in a recent study from the Western State Colorado University (Dalleck. 2016), my life does not depend on it and still, with my tendency to always do too much instead of too little, I am almost certain that I would have made similarly larger strides towards my personal training goals as the sedentary male and female subjects in the previously alluded to recently published study.
One important feature of both training protocols is that they implement periodization schemes.

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The 46 subjects were randomly assigned to one out of three experimental groups: the standardized program group (STD), the ACE IFT group (ACE) and a control group (see Figure 1):
Figure 1: Flow chart of the experimental procedures (Dalleck. 2016).
All underwent the same baseline tests and the subjects in the std. program (according to the guidelines of the American College of Sports Medicine | ACSM) and ACE IFT group trained at the same volume of 150 min/week. What exactly they did and how intense they were training, on the other hand, differed. More specifically...
  • the STD group was prescribed a standardized progressive cardio workout based on the previously determined HR-max (maximal heart rate) values
  • the ACE group was prescribed the same cardio workout, but with the intensity being based on the ventilatory threshold, i.e.the point during exercise at which ventilation starts to increase at a faster rate than VO2. In that, we distinguish between VT1 and VT2, with the former, the First Ventilatory Threshold marking the intensity at which lactate begins to accumulate in the blood (it's also the point where the breathing rate begins to increase and you cannot talk comfortably anymore). VT2, i.e. the Second Ventilatory Threshold, marks the intensity when lactate has already accumulated in the blood and the person needs to breathe heavily - it's also called the anaerobic threshold or lactate threshold.
  • the resistance training program for the STD group was likewise designed according to the ACSM guidelines and involved bench presses, shoulder presses, lateral pulldowns, seated rows, biceps curls, triceps pushdowns, leg presses and extensions, prone lying leg curls, and seated back extensions. Two sets of 12 reps at a moderate intensity of 5-6 on the modified Borg rating of perceived exertion scale (RPE). Resistance was progressed every 2 weeks by ~3-5% for the upper and ~6-10% for the lower body exercises.
  • the resistance training program for the ACE group was designed according to the ACE guidelines (Bryant. 2014) and consisted of multijoint/multiplanar exercises with both free weights and machines (still allowing for free motion during the exercise). The following exercises were performed: stability ball circuit (hip bridge, crunch, Russian twist, plank), lunge matrix, kneeling/standing wood chops, kneeling/standing hay bailers, dumbbell squats, one-arm cable row (standing), step-ups w/ dumbbells (onto 15 cm step), pull-ups (assisted), dumbbell bench press. For each exercise two sets of 12 reps were completed with the resistance progressing by 5%  of the 5-RM every two weeks from 50% in week 1 to 80% in the last week (for the circuit and other exercises where you couldn't change the resistance the same progression model was adapted to the volume).
Do you notice something? Yeah, you can do the ACE program without a personal trainer, as well. As different as it may be, it does not provide any of the individuality a personal trainer who's not following yet another cookie cutter approach (in this case the ACE personal trainer manual | Bryant. 2014) would ideally provide. 
Figure 2: Overview of the pre-post changes in control, STD and ACE (% of baseline | Dalleck. 2016)
This doesn't make the study superfluous or its results invalid (see Figure 2), but it does make the scientists' conclusion kind of confusing, and that despite the fact that...
  • the STD protocol produced 35.7% VO2max non-responders, while the ACE program produced none (all subjects saw increases of 5.9% or more)
  • the STD protocol had only 42.9%, 50%, 85.7% and 42.9% of the subjects achieve meaningful improvements in blood pressure, HDL, triglycerides, and blood glucose, while the corresponding figures for the ACE protocol were 100% for BP, 100% for HTL, 85.7% for trigs and 92.9% for blood glucose - and that in spite of the fact that potential influencing factors such as age, baseline value, exercise adherence, and sex didn't differ
  • the ST program produced improvements in waist and body fat in only 78.6%, while 92.9% and 100% of the subjects in the ACE group saw their waist trim and their body fat melt.
After all, the authors write in their article in the Journal of Fitness Research that their "novel findings [...] underscore the importance of a personalised exercise prescription to enhance training efficacy and limit training unresponsiveness" (Dalleck. 2016) - well, and in all honesty, I cannot see how the ACE program is more "personalized" in the sense of being adapted to the individual than the training according to the ACSM guidelines.
Figure 3: Individual variability in relative VO2max response(%change) to exercise training in (A) the STD and (B) the ACE group (Dalleck. 2016).
So what do we make of the results, then? While you can debate whether the ACE program is more "personalized" than a program that's designed according to the ACSM guidelines, there's no debating its efficacy. As you can see in Figure 2 and 3, the ACE program is not just more effective (  for body fat, lean mass, VO2max, blood pressure, and all balance and strength parameters), there were also no non-responders (see Figure 3 | I personally would have excluded the one individual that regressed significantly; there are probably different reasons than the ACSM program for that) in the ACE group while 5 of the subjects in the STD group saw no or non-significant VO2 improvements.

Overall, the authors of the study at hand are thus right. Their study does "underscore the importance of a personalised exercise prescription to enhance training efficacy and limit training unresponsiveness" what you have to keep in mind, though is that we're not comparing an actually personalized to a standardized exercise prescription, but rather prescribing according to different criteria (cardio: heart rate vs. ventilatory threshold/strength: RPE vs. 5-RM).

Now, one could assume that everything was thus only a result of higher intensities in the ACE group. The actual heart rates, however, didn't differ sign. between the two groups: 107-120 bpm vs. 104-127 bpm for the STD and ACE group respectively. If you're a trainer or a trainee who's not happy with his clients or his own results, trying to train according to the allegedly "personalized" ACE guidelines may well rekindle/promote your progress | Comment!
  • Bryant, Cedric X., Sabrena Newton-Merrill, and Daniel J. Green, eds. ACE personal trainer manual. 2014.
  • Dalleck, Lance C., et al. "Does a personalised exercise prescription enhance training efficacy and limit training unresponsiveness? A randomised controlled trial." Journal of Fitness Research 5 (2016).