Pickleball might look like a casual game, but it is secretly one of the most complete workouts you can get. It challenges endurance, balance, coordination, and power all at once, often without you realizing how hard your body is working. The quick rallies, sudden changes in direction, and bursts of acceleration train multiple muscle groups and energy systems in a way that few other sports do.

In this issue I want to explore what makes pickleball such an effective workout from a physiological standpoint, and then examine what happens afterward. Why do muscles get sore? How does tendonitis develop? And what can you do to keep your body healthy and resilient between games? Understanding both the demands of the sport and the recovery process that follows can help you play better, stay injury free, and enjoy the game for years to come.

Pickleball has a reputation for being light exercise, but the data tells a different story. It combines bursts of sprinting, quick pivots, and precise upper body control, which together create a full body workout that trains strength, endurance, and coordination. The variety of movements means no single muscle group can coast for long, and the unpredictable nature of play keeps your body constantly adapting to new demands.

Every rally in pickleball mimics a short interval of high intensity exercise. The stop and start rhythm forces your heart rate to rise quickly, recover briefly, then rise again. This pattern closely resembles what exercise physiologists call high intensity interval training, or HIIT, which has been shown to improve cardiovascular endurance more efficiently than steady state exercise like jogging. The mechanism is straightforward: when you repeatedly push your heart rate into higher zones and then allow brief recovery periods, you train both your aerobic system and your ability to clear lactate from working muscles. Over time, this increases your VO2 max, the maximum amount of oxygen your body can use during intense exercise, and it lowers your resting heart rate by strengthening the heart muscle itself.

Research on intermittent training shows that this approach also improves circulation by stimulating the growth of new capillaries in muscle tissue, which enhances oxygen delivery and waste removal. Many players are surprised to find that regular play meets or even exceeds the exercise intensity recommended by the American Heart Association for improving heart health, which suggests at least 150 minutes of moderate intensity activity or 75 minutes of vigorous activity per week. A typical hour of competitive pickleball can easily push you into the vigorous category, especially during fast rallies and tournament play.

Your legs do far more than move you from shot to shot. Quick lunges and lateral steps activate the quadriceps, hamstrings, and glutes in patterns that build both concentric and eccentric strength. Concentric contractions occur when muscles shorten under load, like pushing off to sprint forward, while eccentric contractions happen when muscles lengthen under tension, like decelerating from a sprint or absorbing the impact of a lunge. Eccentric work is particularly effective at building strength and resilience, but it also tends to cause more muscle soreness, which explains why your legs might feel tight after a long session.

Calves stay under constant tension during quick starts and stops, which improves both strength and stability in the ankles. The gastrocnemius and soleus muscles work together to control ankle movement, and this repetitive loading helps increase tendon stiffness in a beneficial way, making the Achilles more efficient at storing and releasing elastic energy. The small stabilizing muscles in the hips, including the gluteus medius and minimus, work continuously to keep your center of gravity under control during lateral movements. This builds balance and coordination that carry over to everyday life, reducing the risk of falls and improving overall movement quality.

Almost every shot in pickleball involves trunk rotation. Your core, particularly the obliques and the muscles of the lower back like the erector spinae and multifidus, acts as the engine that transfers force from the legs through the torso and into the paddle. This kinetic chain is essential for generating power without over relying on the arm and shoulder, which helps prevent injury and improves efficiency. The transverse abdominis, a deep core muscle that wraps around your midsection like a corset, stabilizes the spine during rotation and provides the foundation for safe, powerful movement.

This rotational control not only powers your shots but also helps prevent lower back injuries by distributing force across multiple muscle groups rather than concentrating stress in one area. Training these muscles through the sport improves both posture and spinal support, two factors closely linked to long term functional fitness. Stronger core muscles also reduce the compensatory strain placed on the shoulders and neck, which is why players with better core stability tend to experience fewer overuse injuries in the upper body.

The upper body is constantly engaged, even when the motion seems small. Volleys, dinks, and smashes recruit the shoulders, particularly the rotator cuff muscles that stabilize the joint, along with the forearms and grip muscles. The repeated contraction of these smaller muscle groups improves both endurance and fine motor control, which is why experienced players can maintain precision even during long matches. The wrist extensors and flexors, which control paddle angle and absorb impact, develop remarkable stamina through repeated use, though they are also vulnerable to overuse injuries like tendonitis if not given adequate recovery.

The hand eye coordination required to track and return the ball trains reaction time and neuromuscular precision. Your brain learns to process visual information faster and send motor commands more efficiently, which shortens the delay between seeing the ball and executing the shot. This neurological adaptation explains why consistent players often develop faster reflexes and smoother movement patterns outside the sport. The cerebellum, which coordinates movement and balance, becomes more efficient at predicting ball trajectory and adjusting body position in real time.

Pickleball blends resistance, cardio, and coordination into one compact format. You sprint, squat, twist, and react, often without realizing how much work your body is doing. The constant engagement of multiple muscle groups also burns more calories than most people expect, with estimates ranging from 300 to 500 calories per hour depending on intensity and body weight. During longer games, the metabolic demand can be substantial, especially when matches include extended rallies that keep your heart rate elevated for minutes at a time.

What makes it sustainable is that it never feels like exercise. It feels like play, which is why people stick with it and see real results over time. The social aspect and competitive element provide intrinsic motivation that traditional exercise often lacks, and the variable intensity means you can modulate effort based on how you feel without losing the training effect entirely. This combination of physical challenge and enjoyment is rare, and it helps explain why pickleball has become one of the fastest growing sports in the country.

A hard day on the court can leave you feeling strong and energized, but also sore in muscles you did not even know you had. That soreness is not a sign of damage so much as it is a sign of adaptation. Still, if you push too far or recover too little, those same microtears that help you improve can tip into inflammation and overuse injuries such as tendonitis. Understanding what is happening inside your body is the first step toward staying healthy and consistent, and knowing the difference between productive discomfort and warning signs can help you play smarter without cutting your season short.

Muscle soreness after activity, known as delayed onset muscle soreness or DOMS, usually appears 24 to 72 hours after exercise. It happens when the muscles experience microtears from eccentric contractions, the kind that occur when you lengthen a muscle under tension, such as decelerating after a sprint or following through on a backhand. These microtears trigger an inflammatory response that brings white blood cells, growth factors, and nutrients to the damaged tissue. This inflammation is not inherently harmful but rather a necessary part of the repair process.

Your body responds by activating satellite cells, specialized stem cells that fuse with damaged muscle fibers to repair and reinforce them. As the tissue heals over the next few days, the fibers grow back stronger and more resistant to similar stress, which is the fundamental mechanism behind strength and endurance gains. The soreness you feel is caused by a combination of mechanical disruption to the muscle fibers themselves and the buildup of inflammatory mediators like prostaglandins and bradykinin, which sensitize pain receptors in the surrounding tissue.

The key to managing DOMS is giving those tissues enough recovery time while keeping gentle movement going to maintain circulation. Light activity promotes blood flow, which helps clear metabolic waste products and deliver oxygen and nutrients to healing tissue. Complete rest can actually slow recovery by reducing this circulation, which is why active recovery strategies like walking, stretching, or light play are often more effective than doing nothing at all.

Normal soreness fades within a few days as the inflammatory response resolves and tissue repair is completed. If it lingers beyond four or five days, or if the pain sharpens rather than gradually diminishing, it might signal that a muscle or tendon has been overstressed beyond the body's ability to adapt. Acute muscle strains involve more significant tearing of muscle fibers, often accompanied by immediate pain, swelling, and sometimes bruising as small blood vessels rupture. These injuries require longer recovery periods and may need more structured rehabilitation to prevent chronic weakness or reinjury.

Tendons, the connective tissues that link muscle to bone, do not have the same blood supply as muscles, which makes them slower to heal and more vulnerable to chronic problems. Tendon tissue is composed primarily of collagen fibers arranged in parallel bundles, with relatively few cells and minimal vascularity compared to muscle. This means that once a tendon is injured, the healing process can take weeks or even months rather than days. Repetitive stress without adequate rest leads to microscopic fraying of collagen fibers and chronic inflammation, a condition commonly seen in the elbow, shoulder, or Achilles tendon among pickleball players.

Tendonitis usually develops from a combination of mechanical overload and poor recovery. The small stabilizing muscles of the shoulder, particularly the rotator cuff, or the wrist extensors that control paddle angle are often asked to do more work than they are conditioned for. When these muscles fatigue, the tendons themselves must absorb more of the load, which increases the risk of microdamage accumulating faster than the body can repair it. Playing several days in a row without rest, gripping the paddle too tightly, or using improper technique that places excessive torque on vulnerable joints can all contribute.

Once inflammation sets in, the condition can become self perpetuating. Inflammatory chemicals irritate pain receptors, which can cause protective muscle guarding and altered movement patterns that place even more stress on the affected tendon. Tendon cells called tenocytes respond to repeated mechanical stress by producing enzymes that break down collagen, and if this degradation outpaces synthesis, the tendon gradually weakens. This process, sometimes called tendinosis when it becomes chronic, involves actual structural changes to the tendon including disorganized collagen, increased ground substance, and sometimes the formation of abnormal blood vessels and nerve fibers that contribute to ongoing pain. Even daily activities can become painful if the tendon is not allowed to recover, and without intervention, the condition can progress to partial tears or chronic dysfunction.

Treatment starts with relative rest, which means reducing the load without complete inactivity. Complete immobilization can lead to tendon weakening and joint stiffness, so the goal is to find a level of activity that does not aggravate symptoms while maintaining tissue health. Gentle stretching, mobility drills, and light isometric exercises, where you contract the muscle without moving the joint, promote healing without further irritation. Isometrics are particularly useful because they load the tendon in a controlled way that stimulates collagen production and reduces pain sensitivity without creating the high forces associated with dynamic movement.

Ice can help with pain and swelling in the early phase of acute inflammation, typically within the first 48 to 72 hours, by constricting blood vessels and reducing metabolic activity in the injured tissue. However, heat and light activity become more effective once the worst has passed, usually after the first few days. Heat increases blood flow and tissue extensibility, which can improve range of motion and promote healing. Eccentric strengthening exercises, where you slowly lengthen the muscle under load, have been shown to be particularly effective for tendon rehabilitation because they stimulate collagen remodeling and help realign disorganized fibers.

Consistent strengthening of the muscles around the affected joint prevents recurrence by improving load tolerance and ensuring that force is distributed across a broader area rather than concentrated in one structure. For example, strengthening the rotator cuff and scapular stabilizers reduces strain on the shoulder tendons, while building forearm strength protects the elbow. Maintaining hydration supports tissue health by ensuring adequate fluid in the extracellular matrix, and eating adequate protein provides the amino acids necessary for collagen synthesis and muscle repair. Spacing out play days allows sufficient time for tissue adaptation, especially when you are increasing training volume or intensity.

Persistent pain that does not improve after a week or two of relative rest and conservative treatment, noticeable swelling, or weakness in a specific joint should prompt an evaluation by a medical professional. The earlier tendonitis is treated, the easier it is to reverse before scar tissue or chronic degeneration develop. Physical therapists can assess movement patterns and identify biomechanical issues that contribute to overload, while physicians can rule out more serious conditions like partial tears or other structural damage. In some cases, imaging studies such as ultrasound or MRI may be warranted to evaluate the extent of tendon damage and guide treatment decisions.

Advanced cases may require more intensive interventions such as corticosteroid injections to reduce inflammation, though these should be used judiciously as repeated injections can weaken tendons over time. Newer treatments like platelet rich plasma injections or extracorporeal shockwave therapy have shown promise for chronic tendinopathy by stimulating a healing response in damaged tissue. Regardless of the treatment approach, addressing the underlying cause, whether it is technique, equipment, training volume, or recovery habits, is essential for long term resolution.

Pickleball gives you more of a workout than most people expect, but that is also what makes recovery so important. Every quick start, stretch, and swing trains your body, but it also asks for time to rebuild. Muscle soreness and tendon irritation are not signs of weakness but signals that your body is adapting and sometimes asking for rest. The key is learning to balance challenge and recovery so that each session makes you stronger instead of setting you back. In future issues I want to keep exploring these hidden layers of the game, where good health and better performance meet.

Boris.

Disclaimer: This newsletter is for educational and informational purposes only and does not constitute medical advice. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read in this newsletter.