Evaluation of Serum Autophagic Biomarkers in the Acute Response to Walking and Cycling in Healthy Male Individuals

NCT07536659 | Enrolling By Invitation

• 1 other identifier: GOKAEK- 2026/192
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 2

Brief Summary

Physical exercise (walking and cycling) is a potent physiological stimulus that simultaneously alters energy balance, mechanical loading, and metabolic demands in the organism. Autophagy is recognized as a fundamental mechanism in the regulation of acute cellular responses to such stimuli, playing a critical role in maintaining cellular homeostasis, removing damaged proteins and organelles, and ensuring metabolic adaptation \[1\]. Experimental and translational studies have demonstrated that particularly moderate-intensity and controlled mechanical loading can activate autophagic pathways, thereby supporting structural and functional adaptation in muscle, bone, and connective tissues \[2-4\]. In the current literature, the relationship between autophagy and exercise has largely been evaluated through experimental animal models and a limited number of human studies \[5\]. Although animal studies have clearly shown that physiological loading such as walking and running increases molecular signals associated with autophagy, the direct assessment of autophagy at the tissue level in humans is limited due to ethical and feasibility concerns, as it requires invasive methods (e.g., muscle biopsy) \[3\]. Therefore, recent human studies have increasingly focused on indirect evaluation of autophagy through peripheral blood mononuclear cells and circulating biomarkers \[6\]. Indeed, recent human studies have reported that proteins associated with autophagy may exhibit changes in peripheral blood cells or circulation in response to acute exercise, and that this response may vary depending on the type, intensity, and mechanical characteristics of the exercise \[6\]. These findings suggest that autophagy is not merely a tissue-specific process but can also be monitored at the systemic level as part of physiological adaptation \[7\]. However, there is a limited number of human studies that comparatively investigate the acute effects of different exercise modalities with distinct mechanical loading profiles (such as walking and cycling) on serum biomarkers related to autophagy. In this context, the present project aims to evaluate the acute effects of two common aerobic exercise modalities with different mechanical loading characteristics-walking and cycling-on serum biomarkers associated with autophagy in healthy male individuals. In this study, Beclin-1, LC3, and ATG3 levels will be considered not as direct indicators of autophagic flux in tissues, but as circulating biomarkers associated with the initiation and maintenance of autophagy. By examining changes in the serum levels of these proteins following acute exercise, it is aimed to obtain indirect yet biologically meaningful data regarding exercise-induced cellular adaptation mechanisms without the need for invasive procedures. In conclusion, this study aims to contribute to an important gap in the current literature by safely and ethically demonstrating the acute physiological responses related to autophagy in humans across exercise modalities with different mechanical characteristics, thereby enhancing our understanding of the exercise-autophagy relationship.

Conditions

Effects of Walking and Cycling on Serum Physiological Biomarkers

Keywords

Biomarkers, walking, cycling

Outcome Measures

Primary Outcomes (3)

• Beclin-1

  AUTOPHAGY

  1 WEEK

• LC3

  AUTOPHAGY-

  1 WEEK

• ATG3

  AUTOPHAGY

  1 WEEK

Study Arms (1)

walking

cycling

Other: WALKİNG

Interventions

WALKİNG OTHER

Data collection will be carried out in two separate 30-minute exercise sessions, scheduled one week apart. In the first session, participants will perform 30 minutes of walking on a treadmill at a predetermined target heart rate. In the second session, conducted one week later, participants will cycle on a bicycle ergometer for 30 minutes at a similar target heart rate. Apart from the 30-minute exercise modality, all other procedures will be identical in both data collection sessions. To avoid diurnal variations, participants will be asked to attend the laboratory at the same time of day for each session. A minimum one-week rest period will be provided between sessions to minimize potential carryover effects. Upon arrival at the laboratory, an indwelling venous catheter will be inserted into the cubital fossa of either the right or left arm of the participant. To minimize the potential effects of prior physical activity on biomarker concentrations, participants will rest in a supine po

walking

Eligibility Criteria

• Age: 18 Years - 35 Years
• Gender Eligibility Details: HEALTY MALE
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

A total of 20 healthy male volunteers aged between 18 and 35 years, who engage in physical activity at least 2-3 days per week for a minimum of 30 minutes and have no known health problems, will be included in the study. To avoid the effects of previous medical conditions, individuals with acute or chronic injuries in the bilateral/unilateral lower extremities, musculoskeletal disorders, or a history of surgical intervention to the hip and/or knee joints will be excluded from the study. Participants will be instructed to minimize all sports activities 48 hours prior to the assessment days; however, normal daily activities such as walking and stair climbing will be permitted. In addition, participants will be advised to maintain their usual daily routines and to consume the same types of food on the assessment days.

You may qualify if:

• Healthy male volunteers aged 18-35
• Engaging in physical activity at least 2-3 days per week for a minimum of 30 minutes
• Having no known health problems

You may not qualify if:

• Individuals with acute or chronic injuries in the bilateral/unilateral lower extremities
• Individuals with musculoskeletal disorders in the bilateral/unilateral lower extremities
• Individuals who have undergone surgical intervention to the hip and/or knee joint
• Individuals with cardiopulmonary problems that would prevent them from performing exercise

Sponsors & Collaborators

• Kocaeli University: lead
• Sakarya University of Applied Sciences: collaborator

Study Sites (2)

Kocaeli University Faculty of Medicine Hospital

Kocaeli, Turkey (Türkiye)

Location

Sakarya University of Applied Sciences Physiotherapy and Rehabilitation Research Center

Sakarya, Turkey (Türkiye)

Location

MeSH Terms

Interventions

Walking

Intervention Hierarchy (Ancestors)

Locomotion; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise; Motor Activity

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assoc. Prof.

Study Record Dates

• First Submitted: April 11, 2026
• First Posted: April 17, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): October 30, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: April 21, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (2)