Musculotendinous Adaptations to Strength and Endurance Training in Cyclists

NCT07658300 | Completed

• 1 other identifier: MNl-SVa(M)-2023-578
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

This study investigated whether adding strength training to regular endurance training improves performance and muscle function in competitive cyclists. Endurance training is essential for cycling performance, while strength training has been widely recognised as a complementary strategy that may enhance performance and reduce injury risk. However, in practice, strength training is often performed only during limited periods of the training season, and it remains unclear to what extent the adaptations achieved are maintained during subsequent phases of endurance-focused training. Male competitive cyclists were assigned to either a 10-week off-season combined strength and endurance training programme or an endurance-only training programme. The strength training group performed two weekly strength sessions in addition to their usual cycling training, while the control group continued with endurance training only. Participants were assessed at four time points: before the intervention, after the initial 10-week training period, after a high-volume endurance training camp, and during a competition preparation phase. Measurements included body composition, muscle strength, explosive force production, muscle and tendon structure, and cycling performance variables such as maximal power output and aerobic capacity. The primary aim of the study was to determine whether short-term strength training enhances neuromuscular performance and muscle-tendon characteristics in trained cyclists, and whether these adaptations are maintained or reduced when strength training is discontinued. A secondary aim was to examine how these changes interact with endurance adaptations across different phases of the training season. It was hypothesised that strength training would improve muscle strength, power, and muscle-tendon structure, but that these adaptations would be partially reduced during subsequent training phases without continued strength stimulus.

Conditions

Healthy Adult; Cyclists; Athletes

Keywords

strength training; endurance training; cycling performance; skeletal muscle; tendon

Outcome Measures

Primary Outcomes (5)

• Knee extensors strength - One repetition maximum (1RM) (kg)

  Maximal strength (kg) for the leg extension was estimated from a five-repetition maximum (5RM) test conducted according to National Strength and Conditioning Association guidelines in two exercises (barbell squat and leg press). The corresponding 1RM values were estimated using the ExRx.net calculator.

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Quadriceps muscles thickness (mm)

  Quadriceps muscle thickness (mm) (vastus lateralis, rectus femoris, vastus medialis) assessed using B-mode ultrasound imaging.

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Maximal voluntary isometric contraction (Nm)

  Isometric maximal voluntary contraction (MVC) of the knee extensors assessed using an isokinetic dynamometer (System 3; Biodex Medical Systems, Shirley, NY, USA). Following a 5-min warm-up on a cycle ergometer at a self-selected workload and cadence, participants were seated upright in the dynamometer chair with double shoulder straps securing the upper body and were verbally encouraged to exert maximal effort. Three MVC trials were performed at a knee joint angle of 70 o (full extension = 0 deg) and the highest peak torque (Nm) was used for analysis. Each trial was separated by 1 minute of rest, and two submaximal warm-up contractions were completed before testing.

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Isokinetic peak torque (Nm)

  Isokinetic concentric peak torque of the knee extensors assessed using an isokinetic dynamometer (System 3; Biodex Medical Systems, Shirley, NY, USA). Following a 5-min warm-up on a cycle ergometer at a self-selected workload and cadence, participants were seated upright in the dynamometer chair with double shoulder straps securing the upper body and were verbally encouraged to exert maximal effort. Three maximal concentric contractions performed at a knee joint angle of 70 deg (full extension = 0 deg) and at 60 deg/s, and the highest peak torque (Nm) was used for analysis. Each trial was separated by 1 minute of rest, and two submaximal warm-up contractions were completed before testing.

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Patellar tendon cross-sectional area (mm2)

  Patellar tendon morphological changes assessed using B-mode ultrasound imaging - cross-sectional area (square millimetres).

  Baseline (Week 0), Week 10, Week 14, and Week 18

Secondary Outcomes (9)

• Body mass (kg)

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Height (cm)

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Body mass index (BMI) (kg/m2)

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Body fat %

  Baseline (Week 0), Week 10, Week 14, and Week 18

• Maximal oxygen consumption (VO2max) (L/min, ml/min/kg)

  Baseline (Week 0), Week 10, Week 14, and Week 18

Study Arms (2)

Endurance Training (END)

ACTIVE COMPARATOR

Endurance training group, performing their classical training routine

Behavioral: Endurance training

Strength + Endurance Training (ST)

EXPERIMENTAL

Strength training group, performing 10-weeks off-season strength training (2 session/week) in addition to their endurance training routine.

Behavioral: Strength training; Behavioral: Endurance training

Interventions

Strength training BEHAVIORAL

Participants allocated to the combined strength and endurance training group completed two supervised strength training sessions per week for 10 weeks in addition to their habitual cycling training. The strength programme targeted major lower-limb muscle groups (e.g., quadriceps, hip extensors) and was designed to improve maximal strength and explosive force production using multi-joint resistance exercises. Training variables (e.g., load, volume, progression) were adjusted throughout the intervention according to training phase. The endurance-only group continued their usual cycling training without additional strength training. Following the intervention, all participants performed endurance-only training during a high-volume training camp and a subsequent competition preparation phase.

Strength + Endurance Training (ST)

Endurance training BEHAVIORAL

The endurance-only group continued their usual cycling training without additional strength training. Following the intervention, all participants performed endurance-only training during a high-volume training camp and a subsequent competition preparation phase.

Also known as: Endurance only training

Endurance Training (END); Strength + Endurance Training (ST)

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Male competitive cyclist
• Aged 18 to 40 years
• Minimum of 3 years of structured cycling training experience
• Actively competing during the previous cycling season
• Following a structured training programme with planned competitions
• Able to participate in all training sessions and testing procedures
• Free from medical conditions contraindicating high-intensity exercise

You may not qualify if:

• Current musculoskeletal injury or pain affecting training or performance
• History of major lower-limb injury within the past 10 years
• Presence of any cardiovascular, neurological, or metabolic disease
• Use of medications that may affect physical performance or training adaptations
• Inability to comply with the training programme or testing schedule
• Participation in another structured strength training programme during the study period

Sponsors & Collaborators

• Lithuanian Sports University: lead

Study Sites (1)

Lithuanian Sports University

Kaunas, LT-44221, Lithuania

Location

Related Publications (7)

• Cesanelli L, Ammar A, Arede J, Calleja-Gonzalez J, Leite N. Performance indicators and functional adaptive windows in competitive cyclists: effect of one-year strength and conditioning training programme. Biol Sport. 2022 Mar;39(2):329-340. doi: 10.5114/biolsport.2022.105334. Epub 2021 Apr 21.

  PMID: 35309528 BACKGROUND

• Bini RR, Flores Bini A. Potential factors associated with knee pain in cyclists: a systematic review. Open Access J Sports Med. 2018 May 23;9:99-106. doi: 10.2147/OAJSM.S136653. eCollection 2018.

  PMID: 29872355 BACKGROUND

• Bohm S, Mersmann F, Arampatzis A. Human tendon adaptation in response to mechanical loading: a systematic review and meta-analysis of exercise intervention studies on healthy adults. Sports Med Open. 2015 Dec;1(1):7. doi: 10.1186/s40798-015-0009-9. Epub 2015 Mar 27.

  PMID: 27747846 BACKGROUND

• Ronnestad BR, Mujika I. Optimizing strength training for running and cycling endurance performance: A review. Scand J Med Sci Sports. 2014 Aug;24(4):603-12. doi: 10.1111/sms.12104. Epub 2013 Aug 5.

  PMID: 23914932 BACKGROUND

• Pallares JG, Barranco-Gil D, Rodriguez-Rielves V, de Pablos R, Buendia-Romero A, Martinez-Cava A, Franco-Lopez F, Sanchez-Redondo IR, Iriberri J, Revuelta C, Lillo-Bevia JR, Valenzuela PL, Lucia A, Hernandez-Belmonte A, Alejo LB. Cyclists do not need to incorporate off-bike resistance training to increase strength, muscle-tendon structure, and pedaling performance: Exploring a high-intensity on-bike method. Biol Sport. 2025 Feb 5;42(3):185-195. doi: 10.5114/biolsport.2025.146790. eCollection 2025 Jul.

  PMID: 40657002 BACKGROUND

• Mujika I, Ronnestad BR, Martin DT. Effects of Increased Muscle Strength and Muscle Mass on Endurance-Cycling Performance. Int J Sports Physiol Perform. 2016 Apr;11(3):283-9. doi: 10.1123/IJSPP.2015-0405.

  PMID: 27068517 BACKGROUND

• Vikestad V, Lyngstad IK, Dalen T. Strength training among professional UCI road cyclists: Practices, challenges, and rationales. PLoS One. 2025 Jul 10;20(7):e0328195. doi: 10.1371/journal.pone.0328195. eCollection 2025.

  PMID: 40638631 BACKGROUND

MeSH Terms

Interventions

Resistance Training; Endurance Training

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 1, 2026
• First Posted: June 18, 2026
• Study Start: September 1, 2023
• Primary Completion: June 1, 2024
• Study Completion: June 1, 2024
• Last Updated: June 18, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

LI (1)