---
title: Recovery From 50 Eccentric Biceps Curls in Young, Untrained Men and Women
nct_id: NCT05036239
overall_status: COMPLETED
phase: NA
sponsor: Norwegian School of Sport Sciences
study_type: INTERVENTIONAL
primary_condition: Recovery
countries: Norway
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT05036239.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT05036239"
ct_last_update_post_date: 2023-11-30
last_seen_at: "2026-05-12T06:27:31.914Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Recovery From 50 Eccentric Biceps Curls in Young, Untrained Men and Women

**Official Title:** Recovery After Exercise-Induced Muscle Damage

**NCT ID:** [NCT05036239](https://clinicaltrials.gov/study/NCT05036239)

## Key Facts

- **Status:** COMPLETED
- **Phase:** NA
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 15
- **Lead Sponsor:** Norwegian School of Sport Sciences
- **Collaborators:** Université de Nantes, Oslo University Hospital, University of Oslo, Syddansk Universitet, Denmark, University of Copenhagen
- **Conditions:** Recovery, Muscle Damage, Muscle Stiffness, Cell Structure Alteration, Calcium Cycling
- **Start Date:** 2019-12-03
- **Completion Date:** 2020-12-20
- **CT.gov Last Update:** 2023-11-30

## Brief Summary

The purpose of the study is to investigate muscle stiffness in relation to muscle damaging work and to investigate how well the change in muscle stiffness correlates with the degree of muscle damage (myofibrillar disruption and necrosis). To date, the reduction in force-generating capacity is the best non-invasive marker of muscle damage. It is already established that muscle stiffness correlates well with the decline in force-generating capacity after damaging exercise. However, the correlation between degree of muscle damage and muscle stiffness has not yet been investigated. The main focus of the study is therefore to investigate the relationship between muscle stiffness and muscle damage. Further, the researchers aim to investigate how calcium cycling is affected by damaging work, and if impaired calcium cycling may partially explain the observed reduction in force-generating capacity.

## Detailed Description

Regardless of whether an individual is in rehabilitation or exercise for general health or athletic performance, resistance exercise is an essential form of exercise when the goal is to increase muscle mass, strength and function. Although, resistance exercise primarily is associated with positive effects it may also result in muscle damage when the exercise is of high intensity and/or unaccustomed. This is known as exercise-induced muscle damage (EIMD) and is reflected by a substantial decrease in force-generating capacity and often accompanied by intracellular swelling and delayed onset muscle soreness. On a cellular level, EIMD include myofibrillar disruption, inflammatory response and in severe cases of EIMD; myofibre necrosis. While EIMD with its symptoms clearly is evident, its underlying mechanisms are still to be fully elaborated.

One interesting hypothesis regarding the molecular basis of decreased muscle strength as a result of EIMD, is related to the strain of this exercise mode causing "popped" sarcomeres. When sarcomeres are stretched beyond actin-myosin overlap, some sarcomeres may over-stretch. This results in overload of membranes, leading to opening of stretch-activated channels, and subsequently influx of Ca2+. High levels of cytoplasmic Ca2+ may cause degradation of contractile proteins or Excitation-Contraction coupling proteins mediated through increased calpain activity. However, a recent study by Cully and colleagues (2017) suggest a protective mechanism post heavy-load strength training related to Ca2+-handling. Cully et al. observed formation of vacuoles in longitudinally connecting tubules post exercise when exposing fibers to 1.3 μM \[Ca2+\] in the cytoplasma. These vacuoles provide an enclosed compartment where Ca2+ can be accumulated, preventing Ca2+ from initiating damage to the muscle. The role of Ca2+-regulation in recovery of muscle function warrants further investigation and clarification.

To the best of the investigators knowledge, the most valid method for estimating EIMD is by investigating myofibrillar disruption, and in some cases necrosis, in muscle biopsies. This requires many resources and is rather expensive. Currently, the best non-invasive marker of muscle damage is the force deficit observed at 48 hours post exercise. However, a measurement estimating muscle damage immediately post exercise is warranted because force deficit immediately post exercise will be confounded by muscle fatigue.

A novel study performed by Lacourpaille et al. (2017) showed a strong negative correlation (-0.80) between stiffness of the muscle tissue, shear modulus, measured 30 minutes post exercise and peak isometric force measured at 48 hours post exercise and therefore a strong relationship between the decline in force production capacity and increased stiffness post exercise, suggesting a possible method to predict EIMD immediately after exercise. However, direct evidence of this association is warranted, with measurements of shear modulus and EIMD biomarkers, such as the proportion of disrupted fibers and sarcoplasmic Ca2+ regulation.

The ability to predict EIMD after training is of great interest to athletes, but also patients suffering from e.g. muscular dystrophies. Being able to predict EIMD quickly and non-invasively after exercise will help employ optimal recovery.

The aim of this project is to investigate the link between exercise-induced muscle damage (EIMD) as changes in shear modulus by ultrasound shear wave elastography, and muscle damage as observed in the analysis of muscle biopsies. The hypothesis is that there is a strong relationship between muscle stiffness acute post exercise and degree of muscle damage observed in muscle biopsies. A secondary aim is to further the understanding of cellular mechanisms causing EIMD and the role of Ca2+ in the recovery of muscle function.

## Eligibility

- **Minimum age:** 18 Years
- **Maximum age:** 35 Years
- **Sex:** ALL
- **Healthy Volunteers:** Yes

```
Inclusion Criteria:

\- 18 to 35 years of age

Exclusion Criteria:

* Injury to the muscle-skeletal system
* Other conditions causing inability to perform heavy-load resistance exercise
* Having engaged in resistance exercise targeting the m. biceps brachii once a week or more over the past year
```

## Arms

- **Exercised** (EXPERIMENTAL) — One bout of 50 eccentric biceps curls
- **Control** (NO_INTERVENTION) — No eccentric biceps curls

## Interventions

- **Eccentric biceps curls** (OTHER) — 10 x 5 repetitions of eccentric biceps curls, interspaced by 30 seconds of rest.

## Primary Outcomes

- **Change in muscle strength** _(time frame: Baseline, and 5 minutes, 3 hours, 24 hours, 48 hours, 72 hours, and 96 hours after eccentric biceps curls)_ — Recovery of arm flexion torque
- **Change in muscle stiffness** _(time frame: Baseline, and 50 minutes, 3 hours, 24 hours, 48 hours, 72 hours, and 96 hours after eccentric biceps curls)_ — Muscle stiffness measured with shear wave elastography as mean young modulus in different conditions (static and dynamic)
- **Change in muscle damage** _(time frame: 2 hours, 48 hours, and 96 hours after eccentric biceps curls)_ — Development of myofibrillar disruption and necrosis observed in skeletal muscle biopsies with electron and confocal microscopy
- **Change in calcium cycling** _(time frame: 2 hours, 48 hours and 96 hours after eccentric biceps curls)_ — Calcium cycling in muscle single fibers and Sarcoplasmic reticulum-homogenate

## Secondary Outcomes

- **Change in organization of the tubular system in skeletal muscle** _(time frame: 2 hours, 48 hours and 96 hours after eccentric biceps curls)_

## Locations (1)

- Norwegian School of Sport Sciences, Oslo, Norway

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `sponsor.collaborators` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.norwegian school of sport sciences|oslo||norway` — added _(2026-05-12)_

---

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*Source data (authoritative): https://clinicaltrials.gov/study/NCT05036239*  
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