Tuesday, December 18, 2012

Ballistics Lunge Activates Muscle to Just Like 34% Lighter Standardlift, Elastic Band & DBs Target Different Muscles. Plus: 10 Reasont to do Explosives & Plyometrics

Lunge with resistant bands as it was done in the study (Jakobsen. 2012)
The paper the Danish researchers Jakobsen, Sundstrup, C.H. Andersen, Aagaard and L. Andersen are about to publish in one of the forthcoming issues of Human Movement Science is not the first certainly won't be the last study on explosive training (more) and plyometrics (more) you have and still will read about, here at the SuppVersity. And while I am not sure whether you would say that it is the most exciting one, I am pretty convinced that you will be inclined to hear how different rep-speeds (ballistic=explosive vs. normal) effected the EMG activity during a full-body exercise like lunges with different loads and equipment (dumbbells vs. resistant band).

Before we start, just a brief reminder for all of you who have not read the SuppVersity EMG series as of now. If you want to know the "best" exercises to target specific muscle groups, I'd suggest you make a detour to all or just those body parts you are interested in by clicking on the respective image in the "navigation" below:
Navigate the SuppVersity EMG Series - Click on the desired body part to see the optimal exercises.
Apropos, lunges were (unfortunately) not among the exercises the researches tested in the study the EMG series is based on. I personally consider them extraordinary valuable for whole leg development, and have to caution you that comparing squats to lunges on EMG basis is somewhat like comparing different types of red using black and white photos, because one of the main and in my humble opinion probably the most important argument against the significance of EMG measurements is that they tend to increase with the degree of weight you can move - this puts lunges in as much into a somewhat disadvantaged position as flys as a chest exercise and could lead to the misunderstanding that it would be better to perform 10 sets of squats than 5 sets of 5 for squats and 4 sets 10 for lunges as a legworkout. Especially if your goal is skeletal muscle hypertrophy, the latter is usually (you know there are no black-and-white solutions) the far superior choice.

Same activation with less load = training economy

That being said, the results of the Jakobsen study do still have their merit. After all, they clearly show that doing explosive or ballistic movements can provide diversion and new growth stimuli especially on those "auxilliary" exercises like lunges. In that, the lower overall weight can even come very handy as it should effectively reduce the risk of injury, which is - let's be honest - a very good argument not to do max. squats in a ballistic fashion, at all.
Figure 2: Normalized EMG activity during lunges with elastic bands and dumbbells (Jakobsen. 2012)
In fact, the EMG measurements, the scientists took while their subjects, 42 subjects (18 men, 24 women; age 41/45 years, BMI 24/25m²/kg, respectively), performed unilateral lunges with their dominant / preferred leg using either elastic bands or dumbbells (see image at the top of this article) to adjust the resistance, do actually confirm that training explosively, i.e. performing the lunge movement as fast as possible (ballistic contractions) does provide an increased contractive stimulus (Desmedt. 1977; Frost. 2008; Sakamoto. 2012), which will allow you to ellicit almost identical EMG activity as during controlled reps at a rep-speed of ~3s per rep with 34% less weight. Or as Jakobsen et al. have it:
"[...] ballistic lunges performed with high speed at medium loadings showed broadly similar EMG amplitudes as that seen during slower controlled speeds with high loading." (Jakobsen. 2012)
Furthermore, the "high-speed lunges" obviously took less time and reduced the effective workout time by 23%. Now, while this could be an advantage on days where you have only a very limited time-window to train the researchers argue that this will lead to an overall reduction in time under tension and thus training volume and should - depending on your training goals (my addition) - be compensated by increasing the training volume during power training by ~23 "to  achieve the same accumulated time under tension" (e.g. doing 10 instead of just 8 reps per set).

"Wait, there is something else: What about those hilarious resistance bands?"

Actually, the benefits of explosive/ballistic training are yet only one out of two interesting findings of the study at hand, after all it's likewise interesting to see how the use of those often derided resistance bands effected the EMG activity and other training parameters. So let's see, compared to lunges done with isoinertial loading (=dumbbells)...
  • lunges with elastic bands showed an overall higher EMG activity, which also resulted in a slightly but significantly higher level of perceived loading on the Borg CR10 scale
  • training with resistance bands elicited higher EMG activity in knee and hip extensor muscles (vastus lateralis, vastus medialis, rectus femoris, gluteus maximus) and during the more flexed knee joint positions (i.e., in the reversal phase)
  • performing lunges with resistance bands added an non-linear element to the actual resistance, with the "training load" increasing exponentially as the trainees approached the extended knee joint position 
  • doing lungs with elastic resistance resulted in higher levels of erector spinae and gluteus activity and was more posterior kinetic chain-dominant, which means that they were characterized by higher levels of hamstring, gluteus and erector spinae activity 
The reasons for these differences are actually of biomechanical nature and the outcomes will probably change, if you used the bands differently. So, yes, wrapping the bands around your back / posterior shoulders will be necessary; and yes, only if you use bands similar to the close loop elastic 41 inch bands  (Iron Woody, MT, USA) the scientists used in the study will allow for identical effects (this obviously doesn't mean that you cannot do it with whatever other band you have grabbing them with your hands, but specifically the posterior kinetic chan-dominance is probably not going to be that pronounced if you do that. Why? Because you will miss the anterior pull from the distal attachment of the band below the leading foot, from where it runs to the contralateral shoulder - a pull of which Jakobsen and his colleagues argue that it ...
"[...] creates the need for generating a high net hip extensor moment. In result [...] gluteus, erector spinae and hamstring muscle activity seemed to be elevated in lunges using elastic resistance indicating an effective targeting of the hip and spinal extensor muscles throughout the range of motion." (Jakobsen. 2012)
Done the "right" way, lunges with appropriately selected elastic exercise bands (not the ones you get bundled with Kellog's Special K, or whatever ;-) can therefore be a very effective tool for thigh, hip and back development, and can - with more flexible bands - used as "an ideal exercise modality for the rehabilitation and prophylactic prevention of musculoskeletal disorders" (Jakobson. 2012).

10 scientific pieces of evidence to built a case for explosive training

If the Jakobsen study ain't enough to convince you to spend at least a couple of minutes thinking about whether or not explosive training or plyometrics (which is basically explosive training with body weight exercises) could make a valuable adjunct to your current training regimen the following 10 studies may put you in the right way:
  • How can you easily implement explosive training into your current routine? There are obviously a million of ways you can implement plyometrics and explosive exercises, but if you simply wanted to incorporate them on a strength training day, as an additional, different training stimulus, the protocol the researchers in the PGC-1 α-4 study (see The IGF-1 up- & myostatin down - regulator) looks actually as if it was worth copying. This would mean that you start out with a ballistic movement (B), head into a strength part (S) and then finish up with a hypertrophy exercise (H).

    For leg day this could look like this: (B) 3 sets of ballistic lunges - 10-12 reps, use 66% of 10RM; (S) 5 sets of 5 reps on the leg press or in the squat rack (I suggest the leg press because it's less injury prone with really high weights), stop 1 rep away from failure; (H) 4 sets of 10 reps of deep barbell squats a 10RM + regular calf training.

    Obviously, this is just one way and not the way: You can also do a plyometrics only circle training or do a couple of sets of plyos + a LISS session on a separate day, etc.

    Be creative! Test your ideas and see how you feel, but don't simply add them on top of an already overcrowded workout!
    You can safely combine classic resistance training with explosive lifting without hampering the performance in one or another (Brandenburg. 2005)
  • The addition of explosive training and high-resistance interval training to the programs of already well-trained cyclists improve exercise efficiency and anaerobic threshold and thus produce major gains in sprint and endurance performance (Paton. 2005)
  • If you want to improve your 1-RM max, doing a low volume (2 reps) set of explosive push ups, or  2 medicine-ball (3 to 5 kg) chest passes 30s before the actual lift can help (Wilcox. 2006)
  • Complex training, i.e. combination of heavy lifting and explosives yields higher performance gains than heavy lifting and plyometrics, alone, across all age groups (20, 40, 60y; cf. Dodd. 2007)
  • Explosive resistance training is safe and well tolerated in healthy women even in the eighth decade of life and elicits adaptive neuromuscular changes in selected physiological variables that are commonly associated with the risk of falls and disability in aged individuals (Caserotti. 2008)
  • Explosive plyometrics sessions comprising maximal unilateral countermovement jumps (CMJs), calf and squat plyometric jumps, and short sprints are as effective as shuttle runs in improving maximal running speed in young elite soccer players (Buchheit. 2010)
  • Pimping a regular soccer training with two plyometrics session per week makes it more effective in building general athletic performance (Chelly. 2010)
  • Plyometrics are safe for young children (5-14y) and beginning at 50-60 jumps a session and increasing exercise load weekly results in the largest changes in running and jumping performance (Johnson. 2011)
  • Explosive isometric contractions induce neural and mechanical adaptations leading to large increases in maximum voluntary force production esp. during the early phase of a movement (50ms, +54%; cf. Tillin. 2012)
  • When adjusted to absolute force production, the evoked capacity of the knee extensors for explosive force production and the ability to utilize that capacity during explosive voluntary contractions is similar for males and females (Hannah. 2012)

Bottom line: I guess with the concluding review that obviously raises no claim to completeness it should be clear that the complementation of, yet not (necessarily) the replacement of classic strength & hypertrophy training with plyometrics or explosive lifting with relatively low weight constitutes an effective means to increase the neuronal activation and thus exponentiate subsequent strength and muscle gains.

The Jack-of-All-Traits Leg Workout from the Sáez de Villarreal study I discussed on July 15, 2012, would also be something you may want to look into if you need some inspiration for your own routine.
You should be aware, though that despite the fact that plyometrics and light load explosive lifting do not put a similar strain on your body as the standard high intensity high volume BB routines and will thus probably require less time to recuperate, their incorporation into your routine will make it necessary to cut back on the overall volume of the rest of the exercises (I assume you will up your reps on the plyos anyway, so the total time under tension wouldn't be an issue). Whether you decide to replace a HIIT or regular cardio workout with a longer full body plyometric workout, or doing one exercise less during a hypertrophy specific strength workout in order to make room for additional plyometrics (see example workout to learn how that could look like) is up to you and depends on your current goals and training status.

  • Buchheit M, Mendez-Villanueva A, Delhomel G, Brughelli M, Ahmaidi S. Improving repeated sprint ability in young elite soccer players: repeated shuttle sprints vs. explosive strength training. J Strength Cond Res. 2010 Oct;24(10):2715-22.
  • Brandenburg JP. The acute effects of prior dynamic resistance exercise using different loads on subsequent upper-body explosive performance in resistance-trained men. J Strength Cond Res. 2005 May;19(2):427-32.
  • Caserotti P, Aagaard P, Larsen JB, Puggaard L. Explosive heavy-resistance training in old and very old adults: changes in rapid muscle force, strength and power. Scand J Med Sci Sports. 2008 Dec;18(6):773-82.
  • Chelly MS, Ghenem MA, Abid K, Hermassi S, Tabka Z, Shephard RJ. Effects of in-season short-term plyometric training program on leg power, jump- and sprint performance of soccer players. J Strength Cond Res. 2010 Oct;24(10):2670-6. 
  • Desmedt JE, Godaux E. Ballistic contractions in man: Desmedt JE, Godaux E. Ballistic contractions in man: characteristic recruitment pattern of single motor units of the tibialis anterior muscle. J Physiol. 1977 Jan;264(3):673-93.
  • Dodd DJ, Alvar BA. Analysis of acute explosive training modalities to improve lower-body power in baseball players. J Strength Cond Res. 2007 Nov;21(4):1177-82. 
  • Frost DM, Cronin JB, Newton RU. A comparison of the kinematics, kinetics and muscle activity between pneumatic and free weight resistance. Eur J Appl Physiol. 2008 Dec;104(6):937-56.
  • Hannah R, Minshull C, Buckthorpe MW, Folland JP. Explosive neuromuscular performance of males versus females. Exp Physiol. 2012 May;97(5):618-29. 
  • Jakobsen MD, Sundstrup E, Andersen CH, Aagaard P, Andersen LL. Muscle activity during leg strengthening exercise using free weights and elastic resistance: Effects of ballistic vs controlled contractions. Hum Mov Sci. 2012 Dec 8.
  • Johnson BA, Salzberg CL, Stevenson DA. A systematic review: plyometric training programs for young children. J Strength Cond Res. 2011 Sep;25(9):2623-33.
  • Paton CD, Hopkins WG. Combining explosive and high-resistance training improves performance in competitive cyclists. J Strength Cond Res. 2005 Nov;19(4):826-30. 
  • Sakamoto A, Sinclair PJ. Muscle activations under varying lifting speeds and intensities during bench press. Eur J Appl Physiol. 2012 Mar;112(3):1015-25.
  • Tillin NA, Pain MT, Folland JP. Short-term training for explosive strength causes neural and mechanical adaptations. Exp Physiol. 2012 May;97(5):630-41.
  • Wilcox J, Larson R, Brochu KM, Faigenbaum AD. Acute explosive-force movements enhance bench-press performance in athletic men. Int J Sports Physiol Perform. 2006 Sep;1(3):261-9.