Wednesday, October 5, 2011

Increase Your Bench With a Vibrator: 30s in the Squat Position on a Vertical Vibration Platform Between Sets Could Increase Your Total Number of Reps by 6%

Image 1: The FitVibe Excel is the device that was used in the study. The subjects either squatted or did push ups on the machine for the last 30 seconds of their 180s rest-intervals between sets.
When it comes to training methodology it is quite difficult to come up with innovations that really help. One thing that I have always looked down upon as an exercise method for rich, but lazy fat-asses, i.e. training on one of those vibration platforms, has lately gotten a lot of attention, not as a replacement, but as an auxiliary training strategy in the regimen of professional athletes.

Its use as part of regenerative measures has already been studied extensively. Broadbent et al., for example, report statistically significant reductions in delayed onset muscle soreness (DOMS) and interleukin 6 (IL6) in 29 recreational runners, who were exposed to vibration training for 5 days after a 40min downhill run (Broadbent. 2008). And, more recently, Arminian-Far et al. found similar reductions in DOMS, as well as lower creatine kinase levels in untrained subjects if they were pre-treated on a vibration platform for 60s before eccentric leg exercises (Aminian-Far. 2011).

Now, you would be correct if you pointed out that the aforementioned results do not really come as a surprise. After all, the vibration works similar to a massage and will thus help flush nutrients in and degradation products out of the muscle, etc... yet, if that was all it does, how can you explain that squatting on a vibration platform in between sets increased both the explosiveness, as well as the number of reps the subjects in a recent study by P.J. Marin et al. were able to perform on a standard bench press exercise?
Figure 1: Illustration of the study design; condition 1 - 180s passive rest, condition 2 - 150s passive rest + 30s push-ups on vibration plate, condition 3 - 150s passive rest + 30s in the squat position on vibration plate (illustration from Marin. 2011)
The subjects, 9 elite judoists (6 males and 3 females) with 9 years of training experience in judo and 12-13 months of trength training experience, had to perform as much explosive (on the concentric part) repetitions as possible with 60% of their 1RMmax for three sets. Between the three sets they had to perform, one of the three resting strategies illustrated in figure 1 was employed (a counterbalance procedure was used to determine the resting strategy order for each testing session) and the respective number of repetition, the mean and peak velocity, as well as the blood lactate concentrations were recorded.
Figure 2: Number of bench press repetitions the 9 elite judoists performed at 60%RM employing one of the three resting conditions (data based on Marin. 2011)
As the data in figure 2 goes to show the performance increase in the squat condition was small, but statistically significant (+6%, or 2 reps). The performance decrement in the push-up condition, on the other hand, is unmissable and surefire evidence that doing push-ups in between your sets is a performance killer. It is yet noteworthy that neither the improvements nor the decrements in the number of total reps can be explained based on the lactate levels, of which the scientists found that
[t]here was a significant time main effect  (p < 0.05) [but] there was no significant rest strategy main effect [nor a] time × rest strategy interaction effect
The scientists do yet come up with another explanation for the performance improvements that is based on previous observations by Mileva and coworkers, who found that whole body vibration squat exercises can increase the corticospinal excitability and alter intracortical processes, which leads Marine et al. to conclude that
[...] the facilitatory effects of vibration in healthy subjects may be able to influence the excitatory state of the peripheral and central structures of the brain, which could facilitate subsequent voluntary movements. Thus, this could explain how vibration stimuli applied mainly to the lower limbs (such as the WBV used in the present study) could affect upper-limb muscle performance.
In essence, this does not really matter, because if you are a professional athlete, let's say a powerlifter, where those 2 reps can mean the difference between victory and defeat, you probably do not care what the underlying physiological reasons are, as long as it works. If, on the other hand, you are a exercise-fanatic science geek like me, it does not really make sense to spend 7,735.00€ on such a device, when a pound of creatine monohydrate and selecting the most effective exercises for the pecs (cf. The Very Best Exercises for a Chiseled Chest) would probably produce way better results ;-)