In last week’s post, we took a closer look at the force-velocity relationship and it’s underlying science. Recall that when force requirements are high, velocity outputs will be low - and vice versa. This has important implications because of the different movement requirements on a tennis court along with the methods used to improve relevant athletic qualities. Look at the figure below - it’s a theoretical look at where certain movements and strokes etc. lie on the force-velocity curve (this is an adapted representation based on science and my anecdotal experience). Even some of these movements will have different force-velocity requirements at the muscular level - when decelerating for a wide ball for instance, the initial deceleration step will have higher forces acting on the lower-body then the last step just before planting (because we’re trying to stop from a relatively fast movement speed).
In any case, this week’s post will look deeper into each quality and offer more training suggestions. We’ll also provide a progressive training example to increase serve speed by targeting each quality of the curve in an oriented manner.
MAXIMUM STRENGTH IN TENNIS
Many coaches, parents and players believe heavy weight training will make players slow. This is nonsensical, uneducated thinking. Perhaps they relate weight training to bodybuilding style workouts. But I hope by now we know that’s not what we’re referring to. What we’re saying, and what sport science has proven again & again, is that heavy weight training improves maximal force production. There are hundreds of peer-reviewed articles to support this argument....and further to that, both my experiences, and the experiences of my colleagues, point to the same conclusion.
Why is this important? Remember Newton’s 3rd law? For every action, there is an equal (force) and opposite (direction) reaction. Therefore, the more force we apply to the ground, the more force will be exerted. So we’re not necessarily looking at increasing muscle size per se (there will be some increases and this is a good thing...to protect tissues like tendons, ligaments, bone etc.) but rather, we're looking at increasing the force-generating capacity of the system. The system being the player.
How do we do this? The most effective exercises here are the big lifts. For lower body quad dominant strength, the squat. For lower body, posterior strength, the deadlift. For upper body anterior shoulder and chest strength, the bench press (which we've seen Tsonga do in the past). For something which has a more similar movement pattern to the serve, the overhead press. For upper-back & trunk strength, pull-ups.
Notice a pattern? These are big, compound lifts that target large muscle groups, require the recruitment of fast-twitch muscle fibres and have a big influence on maximal force production. When implementing them, we get a preferential shift in utilization of high threshold motor units, which are associated with powerful movements. That means the entire F-V curve shifts upwards - this is especially true for players who haven’t done much lifting in the past.
There’s one caveat here. All of those adaptations we just mentioned (improved recruitment of fast-twitch fibres, preferential shift in high-threshold motor units etc), will occur only if the intent to move heavy loads is high...even when the ACTUAL movement velocity isn’t. When we attempt to move a 3RM back squat with full intent, as fast as we can, it doesn't matter that the movement itself is slow, because we’re attempting to send a fast nervous system response. This is what facilitates improvements in rate of force development (RFD).
Strength-Speed in Tennis
Another big misconception in the tennis world is that Olympic weightlifting exercises are useless. I read on a forum once that Novak and Federer never did any weightlifting, so why would any other tennis player do them? Let’s set the record straight, you DO NOT have to do cleans and snatches to become a better tennis player but improving strength speed - in other words, the ability to produce high amounts of force in the shortest possible time (which Olympic weightlifting exercises target - video below), is paramount. That’s what allows players to move explosively to the ball (recall that movement velocities in tennis are between 0m/s and 1.94m/s - 80% of the time - which means that developing sufficient force to propel ourselves in the direction of the ball, in the shortest time possible, is key).
I can’t stress enough that during each movement, different parts of the the F-V curve could be involved. For instance, when hitting an open stance forehand, strength-speed qualities would predominate when initiating the leg drive, while once we get closer to contacting the ball, we move down the curve into higher velocity segments. So, whether Fed did any Olympic style weightlifting, I don’t know, but I guarantee his trainers worked on this quality in other ways.
And there are other ways. For example, a loaded barbell jump squat is one of those ways. Or a barbell bench press throw. As a coach, you have to weigh the pros and cons first. Olympic weightlifting movements are more technical than jump squats, so you’ll need to spend more time teaching them. If you have time or you’re working with younger athletes, I highly advise it (check out the video from last week’s post). If you have very little time and players have many events coming up, it may be better to implement jump squats. Regardless of your choice, strength-speed is an important quality to train.
Speed-Strength and Reactive Strength in Tennis
Speed-strength is more ballistic in nature. Loads are lighter and movements are faster. Consequently, power output should, in theory, be higher. The acceleration phases of serves and groundstrokes require speed-strength qualities. Similar to strength-speed, Olympic lifts & loaded jumps work well here but at much lighter loads.
This is also where medicine ball work comes into play - which train more of the ballistic components (video below) of strokes. Furthermore, this is where plyometrics play a large role and primarily target changes of direction that require shorter displacement and smaller joint angles. When the situation calls for fast reactions - like when a player is at net waiting for his/her opponent to drill the ball by them - reactive strength is vital. And don't forget about split-step requirements - these are highly reactive in nature. Remember, to train this quality, players must be able to first have good explosive abilities while utilizing the slow stretch-shortening cycle (SSC) and can then progress to fast SSC movements that are more often seen in elite tennis.
One other point to make here. If a player is playing a ton of tennis - which these days, is often the case - they are getting a lot of the reactive plyometric stimuli through the game itself. They are also getting a lot of the specific rotational power (or speed-strength) components from serving and hitting groundstroke after groundstroke - likely the best ways to improve this quality anyway. What they’re not getting, however, is that upper, force portion of the F-V curve. While many other sports perhaps overdue on that end of the spectrum, from what I’ve seen over the years, tennis has been lacking when it comes to that end of the curve. Remember, when we hit all aspects of the curve, the adaptations will hopefully look more like the figure below.
Speed in Tennis
Contrary to what many coaches in the tennis world believe, running 5, 10, 15 or even 20m will not develop speed qualities. And please, if you’re training speed, put the ladder away, it has absolutely nothing to do with speed development. There’s a minimum threshold where maximum speed is achieved for each athlete (and it’s usually around the 40m mark during an all-out sprint). To put that into perspective, a regulation court is about 37m long (from back drop to back drop).
If that’s the case, why train max speed at all? It’s the adaptation we’re looking for - improving the ability to recruit, synchronize & fire type 2 fast-twitch muscle fibres, in an unloaded setting. Also, because getting to maximum speed requires acceleration (supremely important for tennis players), training 40-60m sprints will have a carry over to acceleration qualities. Furthermore, the higher an athlete’s max speed capability (i.e., the more capacity the athlete holds in this quality), his/her type 2 fibres will be more resistant to fatigue.
In any case, max speed won’t take up the bulk of training for tennis players, as there are more important qualities to focus on. Arm - and subsequently, racquet head - speed is one of those qualities. In handball players, throwing velocity improved after heavy bench pressing (Hermassi et al 2011) - which is interesting when it comes to tennis. Perhaps there’s a reason Gil Reyes, Agassi’s former coach, had the retired American star benching over 300lbs later in his career. Or why Tsonga did some bench during post-activation potentiation training during his off-season. But maybe more interesting ways of improving racquet speed on serves and groundies is through overload and underload training. Examples of this include throwing drills to improve high velocity movements of the serving arm and overload/underload racquets. While this type of implement training has been seen to work in tennis (Genevois et al 2012), the research on the topic is scarce. In any event, I see this as the following progression when trying to potentiate the serve for example:
Overhead press (max strength) → Push Jerk (strength speed) → Overhead MB Throw - 2 arm and 1 arm variations (speed strength) → Weighted Racquet Swing (max speed-overloaded) → Regular Racquet Swing (max speed)
You can even take it one step further and use an underloaded racquet - this would produce even more velocity compared to using one’s regular racquet. The progression above is not a workout session, so don’t treat it that way. Most of the research on this topic come from baseball - they have been using these concepts with weighted balls and bats, for decades (read the full review here).
Final Comments
These various qualities (and the associated training means - figure above) should first be trained separately before performing complex work - which is a more advanced form of training that may further increase potentiation. Too often you see juniors performing various forms of complex work when in reality, they don’t have the necessary training background to do so. During development settings, the primary focus should be on the technical aspects of this training prior to adding load. More work is not better, better work is better. What I mean by that is that the quality trumps quantity (I know that’s a cliche but cliches exist because they are true). That said, you’ll be surprised at how learning an Olympic lifting movement like the snatch, can have on improvements in movement patterns and motor control when playing tennis.
Why? As the research suggests, improvements in nervous system function has positive effects on motor coordination. Olympic lifts have a high coordinative demand - there are many moving parts that need to be sequentially coordinated for the most efficient execution (sounds pretty similar to what we’re after in terms of technical execution on the tennis court, doesn’t it?). Furthermore, it’s these heavier loaded, high set, low rep schemes that improve neuromuscular factors without the big increases in muscle size - how do you think weightlifters maintain the same weight class over their careers while continuing to increase strength and power year after year? While 3x10 workouts can play a role in certain settings, most of these programs should be replaced with 5x5, 6x3, 8x2 and so on.
Lastly, I've said this before and I'll say it again, off-court training strategies are used to SUPPLEMENT tennis training, NOT to substitute it. Training as a whole should be organized in such a manner that will improve tennis abilities first, then we see how the rest can fit in. That said, for some, it will mean doing a bit less tennis anyway - if time spent in off-court work is deemed necessary to potentiate the on-court work. this again, is where coaches and trainers should work together to find the formula that works best for their particular situation.