Optimising Tendon Properties for Track and Field Performance
When it comes to getting the best out of our athletes, coaches often focus on developing muscle strength, power, and technique. But what if a key factor influencing speed, explosiveness, and injury prevention has been overlooked?
Tendons play a crucial role in force transmission, elastic energy storage, and overall movement efficiency. Whether it’s a sprinter exploding out of the blocks, a high jumper absorbing and producing force on takeoff, or a distance runner maintaining efficiency over long races, tendon properties directly impact an athlete’s ability to perform at their peak.
Training can actively shape tendon properties, influencing stiffness, elasticity, and resilience—but only when coaches understand how to target the right adaptations for each event. This article breaks down the research and practical coaching strategies to help you integrate evidence-based tendon training into your programs. Learn how to enhance explosiveness, prevent injuries, and optimise tendon function for your athletes across all disciplines.
Physiology of Tendons
What are Tendons?
Tendons are robust connective tissues primarily composed of densely packed collagen fibres arranged longitudinally, providing the critical mechanical link between muscles and bones. This unique structural alignment confers exceptional tensile strength, enabling tendons to withstand considerable forces during athletic movements. Primarily composed of type I collagen, tendons also contain smaller proportions of type III collagen, proteoglycans, elastin, and water, all of which contribute to their viscoelastic properties.
There are over 4,000 tendons in the human body, each playing a role in facilitating movement by connecting muscles to bones. However, as a track and field coach, you don't need to know all of them! It's far more practical and beneficial to focus on understanding and monitoring key tendons directly relevant to your athletes' events.
Use the interactive model below to see how tendons interact with muscles in the lower limb.
Ask Yourself
Which key tendons are most relevant to the events you coach?
Do you or your team consider your athletes' tendon health and function, or is it something you’ve assumed takes care of itself?
Need help answering these questions? Try asking our the AI Assistant by tapping the little icon in the bottom right hand corner. Try asking it “I’m a Coach, What are the key tendons I should know about for the long jump?” or try asking it about your favourite event.
Elasticity and Energy Storage
The defining physiological characteristic of tendons is their ability to store and efficiently release elastic energy. During dynamic activities such as sprinting, jumping, or throwing, tendons cyclically stretch (eccentric phase) and then rapidly shorten (concentric phase)—a process known as the stretch-shortening cycle. Importantly, the effectiveness and efficiency of this cycle are largely dependent on tendon function, as tendons act as elastic springs that store energy when stretched and subsequently release it to enhance movement efficiency and explosive power. Athletes with optimally adapted tendons can therefore execute more powerful and efficient movements.
You should already be very familiar with this key concept from the Level 2 Development Coach program! If you need a refresher, complete Module 3a: Introduction to Conditioning and Plyometrics on the Athletics Learning Centre.
Tendons can be Trained: Adaptability to Loading
Tendons are responsive tissues that significantly adapt when exposed to regular mechanical loading. In simple terms, this means that different forms of training can improve the ability of an athlete’s tendons to perform their function.
· Mechanical (such as stiffness),
· Material (changes quality and organisation of collagen fibres), and
· Morphological (increase in the cross-sectional area).
These adaptations allow tendons to perform more efficiently and cope more effectively with increased stress and strain, contributing positively to overall athletic performance and injury resilience. Specifically, tendons subjected to higher-intensity loads (>70% MVC or 1RM) show the most pronounced increases in stiffness and resilience, highlighting the importance of carefully designed resistance and plyometric programs.
Coaches should understand that mechanical (stiffness) and material (collagen quality and alignment) adaptations occur more quickly and readily than morphological adaptations (increases in tendon cross-sectional area). While structural growth of tendons can take several months to become measurable, improvements in tendon stiffness and underlying material properties often occur within 8 weeks of targeted training.
Ask Yourself
Are your training interventions specifically targeting tendon adaptations, or are they primarily focused on muscular development?
How could you better structure training to enhance both?
Need help answering these questions? Try asking our the AI Assistant by tapping the little icon in the bottom right hand corner. Try asking it “How can I ensure that strength training for my sprinters improves muscular development and also tendon stiffness?”
Blood Supply, Recovery, and the Importance of Training Duration
Tendons have a relatively limited blood supply compared to muscle tissue, meaning they adapt and repair at slower rates compared to muscular tissues. The sparse vascularisation, particularly within certain regions such as the mid-portion of the Achilles tendon, can affect tendon healing and adaptation timelines. Understanding this is critical for coaches to design training programs with adequate recovery intervals, promoting optimal tendon adaptation without inducing overuse injuries.
When considering tendon adaptation, the duration of training interventions plays a critical role. Research indicates that while measurable tendon changes can begin to emerge within approximately eight weeks, adaptations become more significant and robust when training extends beyond twelve weeks. Longer-term interventions (≥12 weeks) result in more pronounced improvements in tendon mechanical properties, particularly stiffness, and the underlying material characteristics. From a coaching perspective, this implies that patience and consistency are crucial—athletes may experience initial functional improvements relatively quickly, but the deeper structural adaptations that provide greater resilience and efficiency in energy transfer take more extended periods of sustained loading to fully develop.
Consequently, training aimed at eliciting substantial tendon adaptations should occur across multiple consecutive training blocks and ideally be scheduled earlier in an athlete’s season, well in advance of the athlete’s intended peak performance period.
| Training Duration | Adaptations | Practical Implications |
|---|---|---|
| 0-4 Weeks | Initial neuromuscular adaptations; minor changes in tendon stiffness | Athletes may not notice major changes; focus on progressive overload |
| 4-8 Weeks | Increased collagen synthesis; early improvements in tendon material properties | Tendons becoming more resilient; continue gradual intensity progression |
| 8-12 Weeks | Notable increases in tendon stiffness; improved energy storage capacity | Athletes may experience improved force transmission; maintain structured loading |
| 12+ Weeks | Significant tendon remodeling; maximal stiffness and structural adaptations | Tendon adapts to high loads; peak performance phase readiness |
Ask Yourself
Do you allow sufficient time for tendon adaptations to occur in your training blocks?
Could a better understanding of tendon recovery help you plan more effective long-term athlete development?
Need help answering these questions? Try asking our the AI Assistant by tapping the little icon in the bottom right hand corner. Try asking it “How long does it take for tendons to adapt to different types of training, and what factors influence the rate of adaptation?”
Tendon Stiffness and Compliance
Stiffness and Compliance
Tendon stiffness refers to the resistance offered by the tendon to deformation under load. High tendon stiffness is advantageous in explosive track and field events, such as sprinting or jumping, because it facilitates rapid force transmission and shorter ground contact times.
Conversely, compliance describes the tendon's ability to stretch under load, beneficial in endurance events requiring greater energy conservation over repetitive actions.
Research indicates both plyometric and resistance training elicits distinct adaptations within tendons, notably changes in tendon stiffness, improved collagen synthesis, and enhanced energy storage and release capacities. Understanding these adaptations is essential for targeted interventions to optimise athlete performance.
Optimal Tendon Stiffness vs. Compliance in Track and Field
It’s important for all coaches to understand that the optimal balance of tendon stiffness and compliance is event-specific. Unfortunately, there isn't absolute agreement on exact values or thresholds for tendon stiffness or compliance across event types. Instead, the concept of an optimal "zone" is generally accepted—where too stiff or too compliant can both be problematic, depending on context.
Ask Yourself
Have you considered whether your athletes’ tendons are too stiff or too compliant for their event demands?
Without access to equipment, how can a coach practically estimate their athlete’s tendon stiffness?
Need help answering this questions? Try asking our the AI Assistant by tapping the little icon in the bottom right hand corner. Try asking it “How can an athletics coach estimate their athlete’s tendon stiffness?”
Increasing Tendon Stiffness with Plyometrics Training
Research consistently highlights certain plyometric training as highly effective in increasing tendon stiffness, essential for explosive events such as sprints and jumps. Key exercises include:
Depth Jumps and Drop Jumps: Studies indicate these exercises, performed at appropriate heights (typically 30-60 cm), significantly enhance tendon stiffness by rapidly loading tendons during eccentric and concentric contractions.
Reactive Bounding and Hopping Drills: Regular integration of bounding sequences or hurdle hops has shown measurable increases in tendon stiffness and enhanced reactive strength index (RSI), positively impacting sprint and jump performance.
Single-Leg Plyometrics: Implementing unilateral plyometric drills such as single-leg bounding or hop series induces asymmetric loading, beneficially stressing tendons and prompting stiffness adaptations, thereby improving unilateral performance and injury resilience.
The study by Burgess et al. (2007) specifically utilised maximal one-legged straight-legged drop jumps over a 6-week training period, progressively increasing the volume from 2 sessions per week (3 sets of 15 repetitions) in the initial week to 3 sessions per week (4 sets of 20 repetitions) by the final week. These plyometric exercises resulted in a 29.4% increase in medial gastrocnemius tendon stiffness, demonstrating significant tendon adaptation and improved tendon mechanical properties.
Find a suggested plyometrics progression series in the video below.
Increasing Tendon Stiffness with Resistance Training
Research highlights that resistance training, especially at high loads (≥70% of 1RM), significantly increases tendon stiffness—critical for explosive track and field events. Key resistance training approaches include:
Heavy Slow Resistance (HSR):
Exercises performed with heavy loads and controlled tempos (e.g., 3–5 second eccentric and concentric phases) significantly enhance tendon stiffness. Movements like back squats, leg presses, and heavy calf raises effectively stress tendon structures, leading to notable stiffness adaptations beneficial for events such as sprints and jumps.Isometric Training:
High-intensity isometric holds (e.g., isometric mid-thigh pulls or static calf raises at near-maximal efforts) have been demonstrated to effectively improve tendon stiffness, offering controlled and safe loading that maximises tension without high joint impact.Eccentric Overload Training:
Resistance training that emphasises the eccentric phase (such as Nordic hamstring curls or single-leg eccentric calf lowers) maximises tendon load and strain, resulting in measurable increases in tendon stiffness and resilience against injury.
A controlled clinical trial investigated the effects of a 12-week high-loading intervention on individuals with Achilles tendinopathy. The study found significant improvements in several parameters exclusively in the high-loading group (Radovanovic et al., 2022):
Plantar Flexor Maximum Voluntary Contraction (MVC): Increased by 7.2% ± 9.9% (p = 0.045).
Tendon Stiffness: Enhanced by 20.1% ± 20.5% (p = 0.049).
Mean Cross-Sectional Area (CSA): Expanded by 8.98% ± 5.8% (p < 0.001).
Maximum Tendon Strain: Reduced by 12.4% ± 10.3% (p = 0.001)
Increasing Tendon Compliance
In contrast, events requiring prolonged repetitive actions (e.g., distance running and race walking) can benefit from increased tendon compliance. Enhanced compliance allows greater energy conservation over repetitive movements and reduces injury risks associated with chronic loading. Methods include:
Submaximal Repetitive Plyometric Drills: Lower-intensity plyometric exercises, such as continuous skipping or repetitive low-height jumps, gradually improve compliance and tendon resilience over extended loading durations.
Moderate-Load High-Volume Training:
Resistance exercises using moderate loads (50–65% 1RM) and higher repetitions (e.g., 15–25 reps per set) promote moderate tendon adaptation, increasing compliance gradually and safely over time.Eccentric Training: Incorporating slow, controlled eccentric training exercises (e.g., heel drops for the Achilles tendon) promotes structural tendon adaptations, enhancing compliance and resilience against chronic tendon overload.
Kubo et al. (2021) showed how plyometric exercises performed at a lower intensity with multiple repetitions can induce greater maximal tendon elongation, making tendons slightly more extensible and enhancing elastic energy storage capacity.
Balancing Performance and Injury Prevention
The Relationship Between Stiffness and Injury
A critical aspect of plyometric training is balancing performance enhancements with injury prevention. Enhanced tendon stiffness, while beneficial for explosive performance, has a complex relationship with injury risk. Excessive stiffness may lead to increased susceptibility to tendon injuries, such as tendinopathies, due to decreased shock absorption capacity and higher peak loads on tendon structures.
Research indicates a correlation between high tendon stiffness and increased incidence of Achilles and patellar tendinopathy in athletes undergoing intense plyometric training programmes without sufficient recovery periods. Conversely, implementing a structured plyometric regimen with controlled progressions and adequate recovery has been demonstrated to significantly reduce injury rates.
On the other side of the equation, tendons that are excessively compliant may also predispose athletes to injury, as they fail to adequately transfer force and store elastic energy, thereby increasing muscular demands and potentially causing muscular overload injuries. Optimal tendon function therefore involves a delicate balance between stiffness (for effective force transmission) and compliance (for sufficient energy absorption and dissipation) based on the athlete’s unique training and performance demands.
Coaches should therefore employ meticulous load monitoring and progressive overload strategies, incorporating rest and recovery periods tailored to athlete responses. Additionally, integrating complementary training methods, such as resistance training and eccentric conditioning, further mitigates injury risks by ensuring balanced tendon adaptations.
Ultimately, an evidence-informed approach to plyometric training emphasising gradual progression, recovery, and individual athlete adaptation is essential for maximising performance while minimising injury risks.
Emerging Perspectives
Can Collagen Peptides Improve Tendon Function and Recovery?
Some emerging evidence suggests that supplementation with collagen peptides may positively influence tendon function and recovery, especially when combined with targeted exercise interventions. A pilot study investigated the effects of specific collagen peptides (TENDOFORTE®) combined with a calf-strengthening programme over six months in patients with chronic mid-portion Achilles tendinopathy. This study reported significant improvements in tendon function and reduced pain, as measured by the Victorian Institute of Sports Assessment–Achilles (VISA-A) questionnaire, indicating that collagen peptides may enhance the therapeutic effects of exercise-based rehabilitation in tendon pathologies.
Similarly, a randomised, placebo-controlled trial exploring the effects of specific collagen peptide supplementation alongside 14 weeks of resistance training demonstrated a notably greater increase in Achilles tendon cross-sectional area (+11.0%) compared to the placebo group (+4.7%). This highlights the potential role of collagen peptides in promoting tendon hypertrophy and suggests that supplementation could help tendons more effectively withstand mechanical loading, potentially benefiting tendon performance and resilience.
Summing Up
The debate continues regarding the ideal tendon stiffness levels, highlighting the necessity for a tailored approach based on the athlete’s event, performance goals, and injury history. Coaches should remain mindful of these varying perspectives, actively monitoring athlete responses to plyometric loads and adjusting accordingly.
Coaches must consider the nuanced relationship between their athlete’s needs, tendon adaptations, and principles of loading to maximise performance benefits and minimise injury risks, adopting evidence-informed progressions tailored to their athletes' individual needs.
Ask Yourself
What is one key change you could make in your training programs to optimise tendon function?
How will you implement this change in the next training cycle?
