The S&C eye
The perspective of the strength and conditioning coach in the tennis court
When stepping onto a tennis court as a strength and conditioning coach, the first and most crucial distinction to keep in mind is the one between training and practice. While they often overlap in the daily schedule of an athlete, their goals, context, and physical demands differ significantly. Observing a player during structured physical training gives you a sense of their general fitness level—mobility, strength, power, and endurance in a controlled environment. But watching them during practice, and especially in match play, reveals a different layer: conditioning. That is, how their body and nervous system respond to stress, fatigue, tactical challenges, and decision-making under pressure. It's in these moments that the gaps between training output and on-court performance become visible.
Equally important is consistency in observation. Seeing an athlete once might tell you what they can do; watching them repeatedly reveals how they do it, and more importantly, how often. Performance trends, movement patterns, recovery behavior, and even emotional responses under stress start to surface only when you track their behaviors across different sessions and situations.
I’d like to share three key things I focus on when I’m on a tennis court, and help you better understand what to observe in detail to identify what the athlete truly needs.
COMUNICATE WITH COACHES:
One of the most valuable yet often overlooked aspects of on-court observation is communication. While our eyes are trained to analyze movement quality, fatigue, or coordination, our ears—and our attitude—play just as important a role. That’s why talking with the coaches is essential. Personally, I prefer to first watch the athlete without any external input, to let my impressions form independently. Only afterwards do I initiate a conversation with the coach, asking for their thoughts on how the player has been performing, what they are working on technically or tactically, and whether the player has reported any pain or discomfort recently.
These conversations aren’t just about gathering data—they serve three strategic purposes. First, the more informed I am, the more accurately I can tailor my support to the athlete’s real-time needs. Second, it strengthens the relationship with the coaching staff. When a coach sees that you’re genuinely invested and trying to align your work with theirs, it builds mutual trust and respect. Finally, and perhaps most importantly, it positively impacts the athlete. When a player realizes that the team around them communicates and works together, it fosters a deeper sense of confidence and security. Even during a gym session, if I refer to what they’ve done on court or what the coach is focusing on, they feel supported by a cohesive structure—not just an individual trainer, but a united team working toward a shared goal.
UNDERSTAND THE LOAD
Another layer of on-court observation that a physical coach should not underestimate is quantifying what actually happens during a session. Coaches, often driven by instinct and experience, are like artists shaping the practice with creativity and flow—but sometimes this means that volume and intensity aren't precisely managed. That’s where we step in. As physical coaches, we need to observe not just how the player is moving, but how much. Did they spend 40 minutes in continuous footwork, or was it a light technical session with long breaks? Did they hit 150 serves or just 20? Often, the coach’s perception doesn’t align with the physical reality—and that’s okay, because in a match you can’t predict how many serves or sprints a player will need. Still, our role is to bring objectivity into the picture.
By collecting basic data—duration of rallies, time spent on drills, number of repetitions—we can help in two key ways. First, we can flag situations where technical repetition is bordering on overload and could lead to overuse injuries. Second, we can adjust the gym work accordingly, scaling intensity or targeting specific qualities based on the session that just happened. Ideally, every phase of a player’s day fits into a larger plan, but in practice that plan often shifts. That’s why we must stay alert, communicate clearly, and remain adaptable. Our job doesn’t stop when the player leaves the gym—it continues on court, with our eyes open and our minds ready to rework the puzzle in real time.
Understanding the training load goes beyond counting minutes. Yes, you can start by tracking the structure of the session: 30 minutes of baseline exchanges, 30 minutes of serving, 30 minutes of technical drills. That already gives a framework. But we also have tools like heart rate monitors, which provide insight into how the athlete’s system is responding. Knowing the heart rate zones they are hitting throughout the session can help you estimate whether they’re working aerobically, anaerobically, or nearing exhaustion.
And yet, some of the most useful signs are still analog—visible in their posture, breathing, and facial expression. A red face, a slouched body, hands on knees: these are clear signs of accumulated fatigue. Breathing patterns also offer valuable cues. As we've explored in various articles, a shift from nasal to mouth breathing can indicate high metabolic stress. If a player is gasping for air with their mouth open after every rally, chances are they’re pushing into the red zone—even if the session wasn’t designed to be maximal.
I remember a conversation with Dalibor Sirola, our head coach, who once pointed out something during a match between Jannik Sinner and Gilles Simon. Although Sinner had superior fitness on paper, Simon’s conditioning and efficiency stood out. Between rallies, Simon remained calm, breathing through his nose, showing no external signs of stress. Meanwhile, Sinner looked flushed, breathing heavily through his mouth, clearly fatigued. Whether it was experience, movement economy, or psychological control, Simon was able to manage the load more effectively in real time—and that made a difference.
OBSERVE HOW THE ATHLETE MOVES
When we talk about how an athlete moves, we’re referring to a wide spectrum of elements—not just speed or quick reactions. There are countless small details that speak volumes about an athlete’s physical qualities, efficiency, and readiness. These are 10 of the key aspects I often observe during both training and matches:
1. Rotational Quality in Groundstrokes and Serve
Tennis demands movement across all three planes: sagittal (e.g., sprinting), frontal (e.g., lateral shuffles), and especially transverse, where most of the strokes happen. Every shot—serve, forehand, backhand—involves a rotational component, making the ability to produce and control rotation a key performance factor.
A critical observation is whether an athlete can generate true rotation through the kinetic chain or if they rely on compensatory patterns. For instance, in the serve, some players substitute rotation with flexion-extension strategies, creating a "catapult" effect that may seem powerful but often leads to inefficiency or even injury risk.
On the forehand, a common mistake is using the entire body to rotate in one block, rather than establishing an anchor point (like the non-dominant hand staying forward) to create separation and true rotational power. When the whole body spins without control, the result is usually reduced accuracy and a loss of speed transfer to the ball. Efficient rotation, paired with relaxation and control, leads to more power and better ball feel.
2. Segmental Control Between Upper and Lower Body
A hallmark of high-level movement is the ability to differentiate upper and lower body actions. As noted by Frans Bosch, one important attractor is "chest out when rotating," which implies that upper-body rotation must be dissociated from lower-body orientation. This is only possible if the pelvis remains stable and the torso rotates with spinal extension.
Another attractor, “keep the head still,” underlines the relationship between visual stability and motor control: head movement should be minimized to preserve visual clarity and enhance movement organization.
Translating this into tennis, we frequently observe how essential it is for the upper body (shoulders and arms) to initiate movement or rotation before the lower body follows. The ability to direct the upper body in one direction while the lower body moves in another is fundamental for vision, anticipation, and coordinated striking.
This upper-lower dissociation is not unique to tennis—it’s seen in many sports, like rugby, where a player may be running forward while tracking or catching a ball mid-air. Developing this skill improves both precision and adaptability.
Functional Ankle Stiffness
Ankle stiffness is often overlooked but plays a crucial role in athletic performance. When we observe an athlete's lower limb behavior during quick movements, we should think of them like springs—not too loose, not overly rigid.
Functional stiffness allows the ankle to store and release elastic energy effectively during explosive actions such as sprints or direction changes. Too little stiffness and the foot collapses, often visible when the heel contacts the ground during acceleration—a red flag for instability and energy leakage. Too much stiffness, on the other hand, can prevent proper shock absorption and fluid movement.
Optimal ankle stiffness provides both support and rebound, especially around 90° of plantarflexion during high-speed foot contacts. It's a fine balance between elasticity and control, essential for quick force transmission and injury prevention.
Lower Body Contribution: Strength and Coordination from the Ground Up
One of the most telling signs of efficient movement is how an athlete uses their legs. In tennis, many players underuse their lower body—not necessarily by choice, but due to a lack of strength, coordination, or intermuscular synergy.
When this connection from the ground up is weak, power is lost along the kinetic chain, and the upper body is forced to overcompensate. This is especially evident in strokes like the serve and the smash, where the inability to generate force from the legs leads to excessive upper body effort.
The result? Reduced performance, less powerful shots, and increased risk of overuse injuries in the shoulder and arm.
Coaches and trainers must look out for this in practice and competition, and design gym and on-court programs that develop lower body strength and improve the ability to integrate it functionally into tennis-specific movements.
Post-Shot Stiffness and Dynamic Control
As mentioned earlier, athletes can be either too stiff or too loose—both extremes are problematic. On a tennis court, this becomes evident particularly after hitting the ball. Young or unstable players often lack the ability to generate the necessary stiffness to decelerate, stabilize, or transfer energy efficiently into the next action, whether it’s a recovery step or a directional change.
More developed athletes, on the other hand, show better control and can “stick” their landing after a shot, transferring their bodyweight into the ball and creating efficient follow-through.
This quality can be enhanced through a combination of bilateral and unilateral strength work, with special attention to eccentric, isometric, and concentric phases.
Exercises aimed at improving core and fascial system stability—especially using submaximal loads, fast execution, and large ranges of motion—can help the athlete build dynamic control. Over time, this leads to greater efficiency both in movement and in energy transfer.
Strength and Stability at End Range
Closely related to the previous point, this concept emphasizes the ability to reach extreme joint positions during play—and more importantly, to generate force from those positions.
In tennis, especially during defensive situations (like wide passing shots or stretched recovery balls), players often find themselves in deep, almost split-like positions. In those moments, performance depends on whether the athlete can remain stable and powerful, even at the limits of their mobility.
As strength coaches, we must observe whether the player can both access and control those ranges.
Training in the gym should include work on end-range strength to provide the necessary adaptations in both muscle and connective tissue. This not only boosts on-court performance but also plays a vital role in injury prevention by making the tissues more resilient in stretched positions.
Load Distribution and Joint Integration
Tennis is a sport driven by intent. When an athlete sees a low ball and decides to hit a crosscourt shot, their body instinctively organizes itself to achieve the goal—it doesn't consciously plan to flex the knee, hinge the hip, or rotate the spine.
If movement quality is lacking, the body will still find a way to reach the ball—but often through compensatory patterns that place excess stress on specific joints or tissues.
An athlete with good general movement capacity (e.g., proper lunge, squat, push, and pull mechanics) will be able to spread the mechanical load across multiple joints, leading to more efficient movement and reduced injury risk.
On the other hand, poor movers will overload certain areas—usually those already prone to stress—simply to accomplish the task.
As performance professionals, our job is to take a holistic view, ensuring that both movement quality and physical capacity are developed in parallel.
Reset Speed and Court Repositioning
One of the most frequent concerns raised by coaches is the so-called “slow feet” of their players. What they usually mean, however, is not pure foot speed, but rather the player’s ability to recover quickly after a shot and reposition effectively on the court. In modern tennis, the ability to transition efficiently from hitting to recovering is essential for maintaining tactical balance and court control. Top-level athletes are highly organized between shots: they maintain posture, adjust their center of mass efficiently, and manage to be in the right place at the right time, not just fast, but with the right intent. This skill is not the result of isolated ladder drills or generic footwork circuits. While these tools can be helpful in specific contexts, real progress comes from a more integrated system that includes strength training to improve force production and deceleration control, movement training to enhance change of direction mechanics, and high-quality technical work on court. Physiotherapy also plays a key role by ensuring joint mobility, tissue quality, and recovery are all optimized to support efficient repositioning.
Sliding Proficiency as a Marker of Athleticism
Sliding has become a defining skill in contemporary tennis, far beyond its traditional association with clay courts. Today’s best movers can slide not only on clay but also on hard courts and, increasingly, even on grass. The ability to slide safely and effectively off both legs allows players to manage wide balls more efficiently, reduce impact on joints, and maintain balance during extreme deceleration. It’s no coincidence that some of the best tennis players in the history—like Federer and Djokovic— said in different interviews that the top players are the top movers. From a developmental perspective, this is a non-negotiable skill. Currently, only a few players in the ATP top 100 struggle with sliding; in a few years, it will likely be a universal standard. As physical coaches, it’s our responsibility to build this ability progressively, starting with eccentric strength, joint stability, and proprioceptive control in the gym, and transferring it onto the court through controlled technical drills, especially during warm-ups or movement-focused sessions. Teaching young players to slide well can significantly elevate their athletic potential and reduce injury risk over time.
Movement Quality Under Fatigue
Movement analysis in tennis should always consider the effects of fatigue. While many athletes move well in the early stages of a session or match, the real test is how their mechanics hold up in the third set—or the fifth, in Grand Slam formats. Fatigue challenges motor control, reaction time, coordination, and decision-making, all of which affect movement quality. That’s why a key role of the athletic trainer is to prepare players to maintain clean, efficient, and intentional movement even under physical and cognitive stress. This doesn't necessarily require extreme conditioning blocks; small strategic interventions can be very effective. For example, integrating strength or metabolic work before on-court drills can simulate match fatigue and force the athlete to execute technique while tired. This creates a more realistic training stimulus and builds both physiological resilience and technical consistency. Ultimately, the ability to keep moving well under fatigue is one of the clearest indicators of physical preparedness and competitive maturity.
I hope these insights will not only spark some reflection but also find real application in your daily work on court and in the gym. Translating observation into action is what makes the difference in the long run. If this helped you refine your eye or gave you a few new angles to consider, then I’ve achieved my goal. Keep observing, keep questioning, and most importantly—keep moving forward with intention.
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