Explosive Exercise: Do We Need It?
Every time I do an initial consultation with a potential client who has past experience with weight training, and has participated in high school and college sports; more specifically foot ball, baseball, and Lacrosse, they use explosive movements when lifting the weight on every set that I have them to do. This, even after I explain to them that I want a slow and controlled lifting technique with a smooth turnaround at both the top and the bottom of the reps. It has happened 100% of the time. The consults that I do with people who never lifted weights before do not do this. They listen to me…and follow my instructions very well.
Explosive movements are when a trainee will jerk, heave, or hoist a weight to get it to start moving, and the trainee attempts to move the resistance as fast as possible. Power lifters, Olympic lifters, athletes of the above mentioned sports, and Cross-fit® disciples are famous for training explosively.
There are two explanations given that I have found for the rationale to do explosive training.
- More muscle fiber recruitment (i.e) making the fast twitch fibers work more thoroughly.
- To get faster and more powerful for the given sport. A good example would be an offensive lineman using Olympic lifts to better “explode” off the line of scrimmage to push back the defensive lineman crouched across him.
One thing is for sure. Explosive lifting, especially with heavy weights increase the potential for injury in a big way. It is too easy to get a herniated disk, rotator cuff tear, elbow tendonitis and other such injuries from explosive training. So, in my opinion, there had better be concrete proof that it produces results that are superior to slower movement weight training.
I will not address the point of whether or not explosive training is a requirement for deeper muscle fiber recruitment, i.e. the fast twitch fibers. I will explore that topic more in-depth in another blog. Suffice it to say here that yes, you do work the fast twitch fibers with slower rep speeds. You do not need explosive exercise to succeed at fast twitch fiber recruitment.
Positive Transfer, Negative Transfer and Neutral Transfer
Coaches want the athletes under their tutelage to do explosive weight training because of the concept of transference. They believe that being explosive with weight will transfer to being explosive on the playing field. Seem reasonable on the surface, but let’s take a closer look.
Research has shown that there are three types of transference. Positive transfer, negative transfer, and neutral transfer.
Positive transfer is where one activity has a beneficial effect on the second activity. A good example of positive transfer is learning how to play the guitar for a couple of years, and then trying to learn how to play the ukulele. Both are string instruments with a similar structure so learning the guitar beforehand will make the learning curve shorter with the ukulele. I have seen this first hand, for my daughter plays both instruments very well (proud of you daughts!).
Negative transfer is where learning one skill will make learning the second skill much harder. I have two examples that come to mind from personal experience. I played baseball most of my childhood (loooved it), and I became a pretty good hitter with power. I learned a specific set of coordinated movement patterns to hit the ball with a fair amount of accuracy and power that took years to develop. When I was older I played softball, and even though I knew how to swing a bat, I could not get a good hit on the ball to save my life. The trajectory and the speed of the ball coming toward me completely threw off my timing and my swing. I played softball for a couple of years and I never felt I got the hang of it. This leads into my second personal experience. Had I known then what I know now about negative transfer, I would not have used the doughnut on my bat to warm up before I went up to bat. A doughnut is basically a 2 1/5 lb weight shaped like a doughnut that you put on the bat to make it heavier while you take practice swings. The theory being that the bat would feel lighter when you do face the pitcher so you can swing the bat faster and with more power. In would not do that now because it turns out that when we practice motor skills, it takes thousands of repetitions in the same setting with the same weighted instrument (say, the weight of a football or the weight of the bat you will use), and the same motion to reach higher levels of mastery of that skill. I have no doubt that using the doughnut for my practice swings made my hitting percentage worse than if I had done no practice swings at all.
Neutral transfer is where the previously practiced skill has no effect one way or another on mastering the new skill set. A clear example of that would be, say, learning how to play the guitar would not influence learning how to be a fastball pitcher.
So, where does explosive training fit into this? Let’s examine the clean and jerk. It is a two-part motion exercise. The first phase of the lift is to lift the bar from off the floor to the upper deltoids. The lifter must jerk the weight off the floor and as the bar is travelling upwards, he must position himself under it properly to land it on his deltoids. The second phase of the lift is to hoist the weight upwards overhead with the elbows fully locked and the lifter standing in the same plane as the torso and bar bell. Just like the first part of the lift, the trainee has to position himself under the bar properly to be able to finish the second part of the lift. You can see that the lift takes a great degree of well executed coordinated movement patterns that takes years to master, so not only is it a strength lift but it is also a skill lift. Moreover, the trainee is learning how to move heavy resistance straight up and down against gravity. If an offensive lineman is using the olympic lift to improve his explosiveness to push back the defender and create an opening for the running back, or to give the quarterback more time to throw the ball, the skill sets he learned from performing the clean and jerk has no meaningful transfer to the skill set he needs to learn on the football field. The clean and jerk skill set will not give positive transfer, nor will it have a negative transfer. It has neutral transfer.
Let’s use another, more common example. The bench press. Just like the Olympic lifts, athletes are taught to do the bench press in an explosive manner, i.e. let the bar come down as fast as possible, bounce the bar off the chest, and then “explode” the bar the rest of the way up. Does this have positive transfer? Doubtful. First of all, the trainee is laying down on a bench, which has no carryover potential to the lifter using that skill set to push a lineman back. Secondly, the lift does not involve the legs, lower back, nor any other muscles that are involved for the lineman. This is another example of neutral transfer.
Applying the knowledge of positive, negative, and neutral transfer to whether a certain style of strength training has more carryover to a sport over a different approach, namely strength training using a slower and more controlled cadence in contrast to a fast and explosive style of lifting, I see no extra benefit to using explosive movements to any given sport. Both styles of lifting will greatly improve strength and general conditioning which does have a positive impact on any given sport, but explosive movements will increase the likelihood of incurring an injury off the playing field. Indeed, even barring injury explosive training can shorten an athletic career because of the undue stress placed on the tendons, ligaments, and joints of the body. I can also say this with certainty….there is no reason for a middle-aged trainee to use explosive exercise to reach a high degree of fitness. It is just not necessary, so why do it?