Musculotendinous Adaptations in High and Low- Performance Triathletes

This study aims to investigate the musculotendinous adaptations in the Achilles tendon and the muscles composing the triceps surae induced by triathlon training and competitions in high-performance and low-performance athletes. Twenty high-performance triathletes, twenty low-performance triathletes, and twenty physically active and healthy individuals of both genders will be recruited to constitute the research groups. Ultrasonography will be employed as the assessment method for the structures of the Achilles tendon and the muscular architecture of the triceps surae. The quality and portability of ultrasonography, coupled with its real-time information capabilities, make it the appropriate choice for this evaluation. The VISA-A scale (Victorian Institute of Sport Achilles Assessment) will be used to measure pain and function of the Achilles tendon. The reliability of ultrasonography measures will be obtained by evaluating images of individuals using the intraclass correlation coefficient, allowing for the analysis of result reproducibility. Data analysis will involve comparisons among the high-performance, low-performance, and physically active groups, aiming to identify differences in musculotendinous adaptations related to performance and injury predisposition. Structural changes occurring in these structures and their potential association with sports performance and/or injury predisposition will be explored. Overall, this study utilizes a comparative cross-sectional research design, where different groups are assessed regarding musculotendinous adaptations in the Achilles tendon and triceps surae through ultrasound-derived measures. The use of the VISA-A scale and the assessment of measure reliability will provide additional data on pain, function, and result reproducibility.

Introduction: Triathlon is a growing sport worldwide, accompanied by a range of injuries primarily linked to the running component, with calcaneal tendinopathy standing out prominently due to the significant demands placed on this structure in both running and cycling. While numerous studies have assessed the architecture of triceps surae muscles and the Achilles tendon in athletes from various sports, exploring both positive and negative adaptations, as well as characteristics associated with improved performance or injury predisposition, there is a notable absence of research specifically investigating these tissues in triathletes. Understanding the architecture of the Achilles tendon and triceps surae muscles in this specific population is crucial for elucidating structural alterations related to performance and injurious changes in these structures. Ultrasound imaging emerges as the standard examination for evaluating these structures due to its quality, portability, and real-time information provision.

Objective: This study aims to identify musculotendinous adaptations in the Achilles tendon and muscles composing the triceps surae induced by triathlon training and competitions in both high-performance and low-performance athletes. These adaptations may be related to injury predisposition and could explain differences in sports performance between groups.

Methods: Twenty high-performance triathletes, twenty low-performance triathletes, and twenty physically active, healthy individuals of both genders will be screened through anamnesis to determine the research groups. Pain and function of the Achilles tendon will be measured using the VISA-A scale (Victorian Institute of Sport Achilles Assessment). The structure of the Achilles tendon and the muscular architecture of the triceps surae will be assessed through ultrasound imaging. The reliability of ultrasound measures will be determined by evaluating images of individuals using the intraclass correlation coefficient.

Eligibility Criteria:
Inclusion Criteria:

High and Low-Performance Triathlete Groups:

* Be a triathlete practicing the sport for more than one year.
* Have participated in and completed at least two triathlon events.
* Maintain regular training at least 4 times per week.
* Be between 17 and 52 years old.

Control Group:

* Be between 17 and 52 years old.
* Engage in regular physical activity (minimum 3 times per week).

Exclusion Criteria:

High and Low-Performance Triathlete Groups:

* Have any disease or injury limiting training and competitions at the time of assessment.
* Not have been training regularly in the last 2 weeks prior to assessment.
* Present acute inflammation, acute pain, or delayed onset muscle soreness on the assessment day.
* Use anabolic steroids.
* Have used steroidal anti-inflammatories in the last 4 weeks before assessment.
* Have used Fluoroquinolone antibiotics in the last 4 weeks before assessment, as they may alter collagen synthesis and induce tendinopathies (ALVES; MENDES; MARQUES, 2019).
* Engage in regular practice of another sport.

Control Group:

* Have any disease or injury limiting physical activity.
* Regularly engage in street running (run at least 20km per week).
* Present acute inflammation, acute pain, or delayed onset muscle soreness on the assessment day.
* Use anabolic steroids.
* Have used steroidal anti-inflammatories in the last 4 weeks before assessment.
* Have used Fluoroquinolone antibiotics in the last 6 months before assessment, as they may alter collagen synthesis and induce tendinopathies (ALVES; MENDES; MARQUES, 2019).
* Have regularly practiced street running at any point in life.