Do Med Balls Develop Power?
I don’t believe that medicine ball training does much in terms of ‘power’ development. There it is, I said it.
My opinion has changed on this topic. I once thought that throwing med balls would develop rotational or overhead power and that this would lead to an increase in groundstroke or serve speed.
I held this belief for a number of reasons.
For one, every elite tennis player on the planet uses med balls in their training. But just because your favorite tour player uses an exercise modality, does that make it useful?
On top of that, there are obvious similarities between the movement patterns of something like a med ball side throw and a forehand. But just because something looks similar, doesn’t mean it’s driving a physiological adaptation.
In this article, I’m going to tell you why my opinion on this topic has changed (hint, it’s got a lot to do with the stimulus - or lack thereof - that med balls elicit). I’ll then present a landmark study that further proves my point.
Finally, I’ll provide a brief summary of why I think med balls are still useful, despite their ineffectiveness for ‘power’ development.
Why did my opinion on med ball training change?
As I mentioned, I was previously convinced that med balls would increase serve and groundstroke velocities. So I devised all these schemes in my programs with that exact intention in mind. To make things more objective, I would track groundstroke and serve velocities using a radar gun - and I would do the same with med ball throws.
The thing is, players I worked with weren’t gaining any speed on their strokes. And there weren’t any significant changes in how hard they threw med balls either. But then I noticed something.
Once they started to adapt to their strength training, that’s when the numbers started to increase. What I ended up realizing was that when they got stronger, they could express more power in things like med ball throws (and serve speed too).
Power is an interesting metric. It can be expressed in many ways but the most prevalent is probably force and velocity (i.e. power = force x velocity). While this topic is one I’d like to tackle in another article, I will say this - trying to ‘optimize’ for power output doesn’t really do much. What we should do instead is tackle one end or the other - force or velocity - then we’ll see a big shift in power!
And in this case, it’s the force side of the equation that was allowing the players I coached to express more ‘power’. Essentially, they were able to exert more force, which contributed to an increase in med ball speed (and stroke speed too!).
Think more about the training stimulus!
The problem with med balls is that they’re very difficult to progressively overload. Do we keep increasing the weight of the ball? But then the movement becomes slower, effectively disrupting the ‘velocity’ component.
Do we maintain the load but increase the speed of execution? This might work early on, but inevitably, we’ll hit a ceiling.
Maybe more throws is the answer? But I don’t believe ‘volume’ is going to help us achieve the desired adaptation here.
And that’s really the point. We need a large enough stimulus to drive a certain adaptation. In the case of med balls, they simply don’t provide a very good training stimulus. You’re not getting stronger. You’re not recruiting high threshold motor units. You’re not training RFD (rate of force development) or ‘power’.
All you’re doing is expressing power!
So what does provide a good stimulus (the force side of the equation)?
Before I answer that, read this quote from an article titled ‘Medicine Ball Training Implications for Rotational Power Sports’ (Earp and Kramer 2010):
Medicine ball training can allow a higher degree of sport specificity to be attained because exercises can be performed that can more closely mimic the range of motion (15) and velocities encountered in sport (3). Thus, such exercises can help build on the sport-generic exercises needed in every program (e.g., squats, bench press, power cleans, etc). Supplemental medicine ball exercises should complement the generic component, and exercises should be chosen to emphasize sport-specific demands such as velocity, plane of movement, and body positioning during the movement.
Two things that stick out:
I agree that ‘generic’ exercises (like squats, bench, cleans) should be in every program. They’re the ones that can provide an actual stimulus (almost indefinitely!). In theory, you can always drive some sort of physiological adaptation with these movements (we’ll get into this more below).
The authors argue that med ball exercises should be used and chosen based on similarities like velocity, plane of movement and body positioning. But do you know what does a better job at tackling these ‘sport-specific demands’? The sport! And in the case of tennis, striking groundstrokes and serves will do this so much better than med ball training ever could.
If you want to hit bigger groundstrokes, just practice that exact ability. Gaining objective feedback with a radar gun can help drive this process.
Med Ball Training vs Weight Training
Let’s dive into an old (but well designed) study for a moment. Newton and McEvoy (1994) compared med ball training vs weight training over an 8-week period in young, male baseball players (average age was 18).
I know we’re not talking about tennis players BUT, throwing a med ball is more ‘similar’ to throwing a baseball (they’re still both throwing actions) compared to throwing a med ball and striking a tennis ball (throwing vs striking). If anything, this should play in favor of med ball throws.
Here are the study details:
Throwing velocity and 6RM bench press were measured pre and post
There were 3 groups, all of which performed regular baseball practice (note that none of them had done any resistance training in the past)
Group 1 - med ball training + baseball
Performed MB throws 2x per week before baseball practice
MB chest pass and MB overhead throw were the 2 exercises; both thrown at max effort (vids below)
After 8 weeks, this group had an 8.9% increase in strength but NO increase in throwing velocity
Group 2 - weight training + baseball
Performed the weight training 2x per week before baseball practice
Bench press + pullover were the 2 exercises (we actually use these w/ players to augment serve velocity potential - see videos below)
After 8 weeks, increased throwing velocity by 4.1% AND increased strength by 22.8%
Group 3 - baseball only (control)
No increase at all in either measure after 8 weeks
This study tells us a few things:
Training (doing something) is better than nothing. In the case of the MB group, while they didn’t increase throwing velocity, they did increase strength. In younger and/or less experienced trainees (like those in this study), even something as low level as a med ball throw can increase strength because it’s a novel stimulus. These results are typically short lived (i.e. we likely won’t see their strength increase much over the long-term).
The MB group did NOT improve velocity at all. MB throws aren’t similar enough to throwing. In comparison, weighted ball throws (underload and/or overload) do in fact increase throwing velocities (this has been studied extensively in baseball). This is because of ‘velocity-specific’ adaptations.
Many will argue that med ball training utilizes a SSC (stretch-shortening cycle) action - i.e. a rapid stretch / lengthening of the muscles + tendons involved in a movement, followed by a powerful shortening / concentric contraction. This issue here is that while there is some SSC involvement, med balls are too heavy for this action to be considered ‘plyometric’.
Maximum limb velocity is determined principally by the rate of force development and overall force output. The authors argue that the ability to produce higher force outputs is likely why the weight training group increased throwing velocity (i.e. strength adaptation). I would agree with that.
Nothing wrong with using a bench press (strategically) to augment stroke speed.
Pullovers can help players achieve better shoulder + thoracic extension (positions we need when serving).
Why med balls are still a useful training tool
My arguments in this post paint a picture of disdain towards med ball training but the reality is, I do still see value in this training modality, just not for power or velocity development.
Before I get there, I know that many will point to studies that have seen increases in certain performance measures as a result of med ball training.
For instance, Szymanski and Pascoe (2007) found that MB training increased various measures of rotational strength in baseball players - but they didn’t actually measure what that did to throwing or batting. The MB group got better at tests that were the same (or similar) to their training program (of course those would improve, but does that matter?).
Other studies (like Ignjatovic et al 2012) use participants that are novice or very inexperienced. Just like we saw in the above study, these subjects will see an increase with ANY type of training that’s thrown at them. Again, this is the novice effect but in my professional opinion, there are far better ways to get stronger, more powerful or hit a tennis ball faster.
A few good reasons to use med balls
Throwing something with intent - like a med ball - might teach an individual how to actually put more effort into a task or skill. Without any actual physiological adaptations, this heightened ‘intent’ could lead to an increase in throwing or striking power - one good reason to keep med balls in the program!
Younger and less experienced players might gain a coordination benefit from med balls. Specifically, if done well, they improve how a player times + segments various body parts. This might transfer over to certain tennis strokes. Strength and power - as we alluded to above - will likely improve in the early stages as well.
On top of that, the momentum of the ball during throw (or non-throw) variations could add a small overload to tissues, allowing a player to increase range in certain patterns (especially when it comes to trunk rotation + overhead shoulder + thoracic extension). This probably has more to do with gaining access to already established ranges of motion, rather than improving long-term mobility.
My friend and colleague, Matt McInnes Watson shared a great YouTube clip on med ball training. He points to using med balls statically, dynamically and ballistically to improve posture as it relates to movement in sport. Another ‘non-power’ oriented use for med balls.
Lastly, med balls can be great as a warm-up tool prior to hitting balls. Using them can increase heart rate, ramp up the nervous system and do so in ways that are conducive to what a player will be doing on the tennis court.
Hammer turns are a great way to mobilize the trunk prior to tennis play.
Extensive (submax) med ball throws can help improving coordination + timing.
But if you want tangible increases in 'power’ or stroke velocity over the long haul, get stronger to improve the force end of the force-velocity spectrum and compliment that by increasingly trying to hit the cover off the tennis ball - the velocity end of the spectrum. Power will take care of itself.