Monday, May 13, 2013

Nautilus? Will a Nautilus-Based "Variable" Training Regimen Yield Greater & More Sustained Muscle & Strength Gains?

Arthur Jones shows a beautiful lady, how his latest Nautilus Pull-Over Machine Works... don't you tell resistance training machines and fitness babes were an invention of the late 1990s ;-)
Although I suspect that most of you are too young to remember the hype surrounding the introduction of the Nautilus Training Systems, I am pretty sure that you will have seen similar machines which are using a nautilus- (a mollusk whose shell has the shape of a logarithmic spiral) or otherwise funkily shaped cams in the place of regular circular wheels, in your gym. The (ingenious?) apparatus was an invention of Arthur Jones (see image on the right), himself a devoted physical culturist, who build the first machines using this by now often-copied mechanism in the late 1960s

The idea behind the concept is that the nautilus-shaped cam would vary the lever over the full range of motion in a way that the intensity would peak at a selected point of the full range of motion. Usually this was and still is, when the muscle is fully contracted and the lever is the shortest.

Ah, yeah that machine... what's it good for? 

These days almost every gym has similar devices, but based on my personal experience most of the "bigger guys" use them - if they use them at all - only for dropsets at the end of their workouts... that raises the question, whether they are big and muscular because they rarely use them or rather despite the fact that they are missing out on the benefits of these devices!? I guess, a similar question must have been bothering Simon Walker and his colleagues from the Department of Biology of Physical Activity and Neuromuscular Research Center at the University of Jyväskylä in Finland (Walker. 2013), when they recruited 33 young men and assigned them randomly to the following three groups
  • constant group:  training legs using regular equipment (no CAM)
  • variable group: training legs using CAM equipment
  • control group: not training at all
While the male particpants in their late 20s were recreationally active (endurance or ball games
activity took place no more than three times per week), none of the subjects had previously taken part in systematic strength training at a frequency greater than once per week.

Usually I'd say that this was a major disadvantage, but in this case using previously untrained subjects ensured that all were exposed to completely novel exercise stimuli, after all, the this was exactly what the scientists wanted to show:

"Does the variable training cause a greater stimulus for continued adaptation?"

Another measure to ensure that the scientists would be able to see practically relevant results was the extension of the exercise intervention over two identical 10-week periods. By doing that, the scientists hoped to be able to (a) elucidate the time course of adaptations (Would the cam system of their Nautilus-like machines produce earlier gains?) and/or (b) whether the regular training would lead to a performance plateau (Would training with a variable loads ensure more persistent gains?).


The above is an illustration of the Strive's Smart Strength technology which works similar to the cam-system in the equipment used in the study at hand. In the latter, resistance increased in line with the force:angle relationship, by ~70 % at 120-180° knee angles in the leg press and by ~30 % at 100-140! at knee angles in the knee extension exercise compared to the constant resistance device at those knee angles, where the scientists installed a simple wheel instead of the CAM.
With the exception of the nautilus-like cam vs. regular wheel in the lower limb machines (leg press,
knee extension, knee flexion), the two workouts per week, which did also involve upper body exercises (bench press, shoulder press, lat pulldown, seated row, bicep curl, triceps push-down, abdominal crunches and back raises) that were conducted on regular resistance equipment, were absolutely identical.
"The subjects performed medium intensity, high volume training con- sisting of two to three sets and 12–14 repetitions (60–70 % 1RM) per exercise (weeks 1–4), then two to three sets and 10–12 repetitions (70–80 % 1RM) per exercise (weeks 5–7) and three to four sets per exercise and 8–10 repetitions (75–85 % 1RM) per exercise (weeks 8–10)." 
After the 10-week period the same set-rep scheme was repeated.In order not to hamper the performance on the tested and thus relevant exercises / body part, the lower limb exercises were performed first in the workout. Moreover, the last set of every* exercise (*my understanding of the FT) was supposed to be performed to failure and the subjects were advised by a nutritional counselor to ingest 20g of protein within <1h after each workout. Furthermore, they were told to make sure that their total daily protein intake had to average 1.5-1.8g protein /kg body mass per day, to optimize the muscle hypertrophy response (the actual intake was controlled only via food logs).

The control group subjects were instructed to maintain their normal physical activity levels and refrain from resistance training throughout the intervention.

"So what were the results, then?"

Actually, a brief glance at the title of the study, "Variable resistance training promotes greater fatigue resistance but not hypertrophy versus constant resistance training", does already provide you with the most important finding of the study - at least if you know that "variable resistance training" refers to using Nautilus-like vs. regular equipment and not, as I initially suspected, a training regimen like the one Adelfo currently favors (check it out), where you incorporate classic high(er) volume and 5x5 workouts into a single routine and spike that up by different RPE schemes.

Now, this would obviously not be the SuppVersity if we did not go beyond what the abstract, let alone the title of the study is telling us. 

So, let's take a closer look at the results, which are - and I can say that without giving away too much in advance, I guess, not exactly earth-shatteringly different. Nevertheless, there is somewhat more to learn, than "just" the fact that the initially mentioned "big guys" are probably not missing any additional muscle stimuli, when they (or you!) stick to free weights (on a side note, I don't know if you ever took into account that for most free weight exercises the resistance decreases, when you contract the muscle?).
Figure 1: Relative changes (compared to baseline) in 1-RM performance, volume load and vastus lateralis CSA (left) and absolute testosterone responses in the variable and constant load groups (right; Walker. 2013)
Despite the fact that it probably does not matter much, the data in figure 1 indicates that even the immediate post-workout testosterone response was marginally more pronounced in the CAM = variable resistance training group. Just like the marginally more pronounced increase in the cross-sectionally area (CSA) of the vastus lateralis (VL), this could yet be a simple function of the higher training volume, which - and this is indicated by the "*" in figure 1 - would be the only advantages of which you could say that they were statistically significant; "significant", because they were statistically significant (pre- vs. post) only in the variable training group. A similar argument may be brought forward in the case of the differential expression of the signaling molecules that control the protein synthetic machinery that's initiated by the muscular contractions during the workout and the subsequent protein ingestion:
"Post-loading phosphorylation of p70 S6K ,rpS6atboth Ser 235/236 and at Ser 240/244 , MAPKAPK-2, and p38 increased following all loadings. Increased phosphorylation of ERK1/2 occurred before training only, and the level of phosphorylation was greater following variable resistance loading compared to constant resistance loading (P<0.05). The level of phosphorylation of p38 was greater following variable resistance loading before training com pared to after training. The phosphorylation of Akt decreased (P<0.05–0.01) following both loadings before training and constant resistance loading after training. There were no statistically significant changes in phosphorylation of mTOR or eEF2 following any loading. There were no changes in total protein or baseline phosphorylation values, apart from increased ERK 1/2 phosphorylation after the training intervention (P<0.05), during loadings." (Walker. 2013)
In the end, we are thus still left with little more than the information that the Nautilus-like came devices that were used in the study at hand offer real advantages only with respect to their ability to induce greater training-induced adaptations in fatigue resistance. This does not exclude superior strength and, what's actually more likely, size gains in the long run - a "run" that would yet obviously have to be longer than 2x10 weeks, though.



And what about free weights? Unfortunately, the Manning study shares one major shortcoming with the study at hand: It does not give us any insights into the question that's probably just preying on your minds: "What about machines vs. free weights?" A couple of paragraphs above, I have already alluded to the fact that the way the resistance varies over the movement is actually reversed, when you compare free weight vs. training on Nautilus-like resistance training equipment. On the latter the resistance increases as you approach the contracted position,. With free weights, on the other hand, it's usually decreasing -- in some extreme cases, such as the standing barbel curl, this decrease is in fact so pronounced that there is almost no external resistance at the end of the exercise.
Bottom line: The results of the study at hand stand in line with previous observations by Manning et al. from the early 1990s. Back in the day, the researchers observed "no difference (P greater than 0.05) between the CR [constant] and VR [variable resistance] groups at any angle, and the magnitude of strength gained was similar (P greater than 0.05) among angles for both groups" (Manning. 1990) in a very similar 10-week study involving 22 men and 27 women in their twenties.

So weights, "Nautilus" or regular pulleys? Or better all of them?

Personally, I second the opinion Stone, Plisk and Collins voiced in a 2002 paper in Sports Biomechanics  the journal of the International Society of Biomechanics in Sports who state that "adherence to the concept of specificity of exercise and training can result in a greater transfer of training effect then free weights should produce a more effective training transfer" (Stone. 2002). For someone training to increase his athletic performance - the question free weights or machines, is thus obsolete and for the rest of us, the use as an adjunct especially towards the end of the workout - just as the initially invoked "big guys" do it - is probably the way to go. After all, training is supposed to stimulate adaptation and to achieve that it is imperative that the stimulus your muscles are exposed to display a certain degree of "novelty". So why not skip on doing another 5 sets of squats and finish your leg workout on the leg press instead? If nothing else, it will allow you to go heavier without risking to injure yourself.

References:
  • Manning RJ, Graves JE, Carpenter DM, Leggett SH, Pollock ML. Constant vs variable resistance knee extension training. Med Sci Sports Exerc. 1990 Jun;22(3):397-401.
  • Stone M, Plisk S, Collins D. Training principles: evaluation of modes and methods of resistance training--a coaching perspective. Sports Biomech. 2002 Jan;1(1):79-103. 
  • Walker S, Hulmi JJ, Wernbom M, Nyman K, Kraemer WJ, Ahtiainen JP, Häkkinen K. Variable resistance training promotes greater fatigue resistance but not hypertrophy versus constant resistance training. Eur J Appl Physiol. 2013 May 1.