Before we can accurately begin developing training programs for our athletes, we should first know a few of the basic scientific training principles that will govern our prescriptions. There are a number of principles - the 4 main ones are as follows: progressive loading, specificity, variation and individualization. While these principles are by no means mutually exclusive, for simplicity, I will present them one by one. In this article, the focus will be on progressive loading.
In tennis, we often talk about a player’s ‘progression’ in terms of their ranking or overall development. While important, these are broad topics that should be dissected further and are beyond the scope of this article. The progressions I’m referring to are based on key variables that can are used to progress an individual’s biomotor capacities (figure below), both on and off the tennis court, over time. That’s what we’ll explore in this post.
Definining Progressive Loading
Progressive loading is a principle based on sport science research. Stone and Plisk (2002) define it as “providing a proper stimulus for eliciting a desired physical, physiological or performance adaptation”. Essentially, we’re aiming to improve an athlete’s capacity - and hence their performance - in some form, by continuously stressing (or loading) them beyond their current state/ability. Traditionally, progressive loading - in the realm of strength & conditioning - has been thought of as the progressive increase in either intensity (load), volume (frequency, duration, number of reps/sets etc) or both.
In theory, it seems pretty simple doesn’t it? Just increase the amount of practice time (duration) on court or add weight (load) to the bar during a squat and there’s your progressive increase in volume and intensity. While these examples are definitely valid, there’s more to progressive loading than simply manipulating these variables. Below we’ll look at a number of ways that progressions can be made both ON and OFF the tennis court.
NOTE - This principle is generally used in performance training (i.e. when organizing strength, power and speed programs). However, because the basic premise adheres to the laws of stress and adaptation - where at it's base, ‘stress + rest = growth’, it can likewise be applied to sport specific training (i.e. tennis).
How close are we training, relative to a player’s maximum - this is how we should look at intensity. Whether that’s in the gym (increasing load on the bar) or on court (increasing effort or intent of a movement). One caveat before we continue - in the tennis world, intensity is often confused with doing lots of work. For example, 2 players perform an X drill (they hit 1 cross-court shot then one down the line). If you’ve ever done this drill you know that movement speed declines as time passes - meaning that you’re no longer working at a high intensity if you go beyond a certain amount of time. Intense efforts can only be sustained for short periods (usually less than 10 seconds). Anything beyond this and we’ll see declines in movement speed, explosiveness and so on. So if you want a player to work on court at a 90-100% effort, the bouts of work have to be short (with high intent).
In any case, as we move through a training cycle, annual plan or years of development, intensity should likewise progress. While juniors may be able to play 15-20 hours a week in their mid-teens, they likely won’t be able to sustain this practice schedule if the intensity of their workouts increase. They’ll simply be working too close to their maximum. This is where rest is crucial as well as the volume of work - the next variable to consider.
In a following post, we’ll outline the manipulation of both volume and intensity (which is the variation principle at play). For now, we can simply frame volume, in the context of progressions, as: performing MORE work. In the gym, it could mean doing more reps at the same load, more sets, an increase in the number of exercises performed and so on. On-court it could mean performing longer sessions, on a macro scale. On a more micro scale, it could mean performing a drill for 15 seconds instead of 10, and attempting to maintain the same intensity throughout.
While intensity and volume are the most common variables many coaches and athletes use to plan and progress their training regimes, others do exist. We’ll explore some of these variables next.
Another important training progression - the amount of times a particular training component is targeted for a specified length of time - is termed density. If we’re talking about reactive strength, for example, how often are we training reactive plyometrics during a week? If it’s high on our priority list, it might be done 2 times a week (the density is 2 in this case). In tennis, an example would be the amount of times an elite player practices their second serve during the course of a week. This is a more specific example - in junior/beginning players, it may simply be the amount of times they practice tennis in a given week.
Density is interesting and doesn’t get the attention it deserves, in my opinion. As a tennis player progresses in their career, they will likely have to increase their density of work to continue improving. Or better yet, they may have to increase the density of specific aspects of their game. Perhaps a high priority for a player is first serves going wide on the deuce court. The density of these serves may be 4-5 times a week for certain players looking to increase their proficiency in this ability. Many elite coaches from various sports have found that increasing density allows for more quality of work - that said, it’s likely the volume within a particular session that decreases to allows this to happen. In other words, I practice serves 5 times a week but only for 20 minutes per exposure rather than 30, 40 etc. to maintain quality of efforts.
FIgure. Progressive Loading in Theory
The arrows signify a training stimulus (i.e. workout). The theory states that if loads are appropriately progressed (greater size in arrow over time), and spaced out accordingly, fitness (of any type), will improve. As we'll see in future posts, training doesn't exactly work in this manner.
Progressions can be made by augmenting the complexity of movements - how coordinatively demanding is an exercise or motion for a player. On court, this may be in the form of a technical progression - i.e. a higher technically demanding skill - or performing the same skill under greater time and pressure constraints. Feeding a ball at faster pace or with more topspin are common examples with younger players. Or perhaps simply playing an opponent who is slightly more advanced (which I have found to be a more specific and challenging form that tests coordination in an open-loop environment).
In the gym it could be as simple as progressing to more coordinatively challenging exercises that perhaps still target the same abilities. A jump squat and a snatch have similar neuromuscular benefits but the snatch is more difficult in it’s execution. Likewise, a unilateral jumping exercise may be more complex for an athlete than a bilateral exercise.
Lastly, both on court and off-court exercises can be more complex by asking a player to perform the same movement with better form - this in itself increases cognitive demand.
This one is pretty self-explanatory but rarely managed well. Before we get into the why, let’s start by looking at a couple of examples. In the gym, moving the same load at a faster pace would be a movement speed progression. On court, gaining serve speed through an increased ability to generate racquet head speed would also be considered a movement speed progression.
The implications, however, are not well understood. If we move a load at a faster speed, we are able to produce more power - this has consequences...it’s physically demanding. If we don’t adjust other variables (volume and density perhaps), then we may overtax the system - leading to undue fatigue, overtraining and/or injury. For instance, a junior who is proficient in serving but doesn’t yet have the stature to serve at a high pace, will be able to serve more serves than one who can hit with greater pace - the latter places more stress on the involved musculatures.
Movement Planes and Directions
Here are another couple of variables that many don’t always consider when working with young players - movement planes and directions. Recall that there are 3 movement planes (sagittal, frontal and transverse) - find out more here. In the gym we can progress exercise selection from sagittal (squat) to frontal (side lunge) or combine planes - transverse and sagittal (lunge with rotation) - for example. Off-court means offer more structure because of the nature of the environment (closed vs open). On-court, however, especially with developing players, we can progress drills and practices to include a variety of movement situations (varying the height of ball, location of the bounce, spin, speed and so on). From a movement perspective, any coach would agree that randomizing these variables would challenge a player to a greater degree than simply working on one at a time.
Range of Motion
This is an important variable to consider. If I maintain the same load in an exercise from one week to the next, but I increase the depth at which I can move through that exercise, I’ve actually increased the internal load on my joints. This is a progression. Similarly, if a player is performing a low-ball drill and hits 100 balls in week 1 and in week 2 they are able to get into a lower lunge position, this should be considered when prescribing the number of balls they’ll hit. Like anything else, when you increase or limit a particular range, all other variables must be carefully considered. An athlete will surely be able to tolerate more load on a half squat than a full squat - for tennis, the former being a better predictor of change-of-direction ability compared to the latter.
Early on in a trainee’s athletic journey, it may seem they are able to tolerate greater loads, volumes, exercise complexities etc. on a regular basis. On a macro level (yearly for example), the hope is that we do see progress steadily rise. In contrast, on a micro level (weekly basis for instance), this is hardly the case.
To conclude, we can agree that all variables are intertwined in some way - when we change one, we have to consider others. All in all, however, it’s important to realize that many progressions exist beyond simply looking at increases in load and/or volume of work. While this post highlights some of these variables, others do exist - exercise order, contraction types and times, rep velocities etc. The purpose isn’t necessarily to highlight every minute detail, but to enable us - coaches and athletes - to think critically about the training process and admit that progress is anything but linear.