Low-Intensity BFR Cycling: Impact on VO₂Max and Muscle Adaptations

NCT07114835 | Completed

• 1 other identifier: BFR-Cycling-2025
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the effects of low-intensity cycling exercise combined with blood flow restriction (BFR) on maximal oxygen consumption (VO₂max), muscle strength, and muscle thickness in sedentary adult males. Participants will be randomly assigned to three groups: (1) a cycling exercise group performing 40 minutes of cycling at 40% VO₂max, (2) a cycling with blood flow restriction group performing 15 minutes of cycling at 40% VO₂max with limb occlusion pressure at 60-80%, and (3) a control group following a shorter cycling protocol. Muscle thickness, isokinetic knee strength, and VO₂max will be measured before and after the 9-week intervention. The study is designed to evaluate whether short-duration, low-intensity cycling with BFR can induce physiological adaptations comparable to traditional longer-duration cycling protocols.

Conditions

Aerobic Capacity; Blood Flow Restriction (BFR) Training Effects; Blood Flow Restriction Exercise; Muscle Strengh; Isokinetic; VO2max

Keywords

Blood flow restriction; aerobic capacity; VO2max; muscle strength; muscle thickness

Outcome Measures

Primary Outcomes (2)

• Change in Maximal Oxygen Consumption (VO₂max, L/min)

  Absolute VO₂max will be measured during a graded cycling exercise test using a breath-by-breath gas analyzer.

  Baseline and Post-test (Week 9)

• Change in Relative VO₂max (ml/kg/min)

  VO₂max will also be reported relative to body weight using standard calculation: (VO₂max ÷ body weight).

  Baseline and Post-test (Week 9)

Secondary Outcomes (4)

• Change in Muscle Thickness (Rectus Femoris, Vastus Lateralis, Biceps Femoris)

  Baseline and Post-test (Week 9)

• Change in Peak Torque (Isokinetic Knee Strength, 60°/s and 180°/s)

  Baseline and Post-test (Week 9)

• Change in Respiratory Exchange Ratio (RER)

  Baseline and Post-test (Week 9)

• Change in Maximal Heart Rate (MHR)

  Baseline and Post-test (Week 9)

Study Arms (3)

Cycling Exercise - 40 min at 40% VO₂max

EXPERIMENTAL

Participants in this group perform low-intensity cycling exercise at 40% of their VO₂max for 40 minutes per session, three times per week, over a 9-week period. All sessions are conducted on an electronically braked Astrand cycle ergometer. This group does not receive blood flow restriction.

Procedure: Cycling Exercise (40 min at 40% VO₂max)

Control - 15 min Cycling at 40% VO₂max

ACTIVE COMPARATOR

Participants in the control group perform cycling exercise at 40% of their VO₂max for 15 minutes per session, three times per week for 9 weeks. The exercise is performed on an electronically braked Astrand cycle ergometer. No blood flow restriction or additional intervention is applied in this group.

Procedure: Short-Duration Cycling Control (15 min at 40% VO₂max)

Cycling + BFR - 15 min at 40% VO₂max with 60-80% LOP

EXPERIMENTAL

Participants in this group perform cycling exercise at 40% of their VO₂max for 15 minutes per session, three times per week for 9 weeks. During each session, pneumatic cuffs are applied to the proximal thighs to restrict blood flow, with individualized limb occlusion pressure (LOP) set at 60% in weeks 1-4, 70% in weeks 5-7, and 80% in weeks 8-9. The exercise is performed on an electronically braked Astrand cycle ergometer.

Procedure: Cycling with Blood Flow Restriction (15 min at 40% VO₂max with 60-80% LOP)

Interventions

Cycling with Blood Flow Restriction (15 min at 40% VO₂max with 60-80% LOP) PROCEDURE

This intervention involves low-intensity cycling exercise at 40% of VO₂max performed on an electronically braked Astrand cycle ergometer for 15 minutes per session. During each session, pneumatic cuffs (10 cm wide, manually adjustable) are applied to the upper thighs to restrict blood flow. Individualized limb occlusion pressure (LOP) is determined via Doppler ultrasound and set progressively at 60% (weeks 1-4), 70% (weeks 5-7), and 80% (weeks 8-9). Sessions are conducted three times per week over a 9-week period. The aim is to simulate the physiological effects of high-intensity training using a low-intensity protocol.

Also known as: BFR Cycling, Low-Intensity Cycling + BFR, CBFR

Cycling + BFR - 15 min at 40% VO₂max with 60-80% LOP

Cycling Exercise (40 min at 40% VO₂max) PROCEDURE

This intervention involves standard low-intensity cycling exercise at 40% of the participant's VO₂max, performed for 40 minutes per session on an electronically braked Astrand cycle ergometer. Sessions are conducted three times per week for a total duration of 9 weeks. This group does not receive any blood flow restriction or external loading. The aim is to observe the effects of traditional low-intensity, long-duration aerobic exercise on VO₂max, muscle strength, and muscle thickness.

Also known as: CEG, Standard Low-Intensity Cycling, Long-duration Cycling

Cycling Exercise - 40 min at 40% VO₂max

Short-Duration Cycling Control (15 min at 40% VO₂max) PROCEDURE

This intervention involves low-intensity cycling exercise at 40% of VO₂max performed for 15 minutes per session, using an electronically braked Astrand cycle ergometer. Participants exercise three times per week for 9 weeks. No blood flow restriction is applied. The aim of this control condition is to match the duration of the BFR intervention while omitting the occlusion component, to isolate the effect of BFR.

Also known as: Control Group Cycling, CG Short Cycling, No BFR

Control - 15 min Cycling at 40% VO₂max

Eligibility Criteria

• Age: 18 Years - 24 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Individuals aged between 18-24 years,
• Individuals without any health problems,
• Individuals who do not actively participate in sports,
• Individuals who marked all items as no on the H+cuff participant information form,
• Individuals who have not had a sports injury that would prevent them from participating in sports in the last 6 months,

You may not qualify if:

• history of lower extremity injury, respiratory disorders and refusal to participate

Sponsors & Collaborators

• Kahramanmaras Sutcu Imam University: lead

Study Sites (1)

Faculty of Sport Science

Kahramanmaraş, Onikişubat, 46050, Turkey (Türkiye)

Location

Related Publications (5)

• Bennett H, Slattery F. Effects of Blood Flow Restriction Training on Aerobic Capacity and Performance: A Systematic Review. J Strength Cond Res. 2019 Feb;33(2):572-583. doi: 10.1519/JSC.0000000000002963.

  PMID: 30531417 BACKGROUND

• Gao Z, Li Y, Zhang J, Li L, Wang T, Wang X, Wang H. Effects of aerobic training with blood flow restriction on aerobic capacity, muscle strength, and hypertrophy in young adults: a systematic review and meta-analysis. Front Physiol. 2025 Jan 7;15:1506386. doi: 10.3389/fphys.2024.1506386. eCollection 2024.

  PMID: 39839525 BACKGROUND

• Zeng Q, Wang L, Zhang Y, Wei H, He Z. Effects of blood flow restriction cycling training on body composition and blood lipids in overweight male college students. Front Physiol. 2022;12:792756. doi:10.3389/fphys.2021.792756 22.

  BACKGROUND

• Abe T, Kearns CF, Sato Y. Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training. J Appl Physiol (1985). 2006 May;100(5):1460-6. doi: 10.1152/japplphysiol.01267.2005. Epub 2005 Dec 8.

  PMID: 16339340 RESULT

• Abe T, Fujita S, Nakajima T, Sakamaki M, Ozaki H, Ogasawara R, Sugaya M, Kudo M, Kurano M, Yasuda T, Sato Y, Ohshima H, Mukai C, Ishii N. Effects of Low-Intensity Cycle Training with Restricted Leg Blood Flow on Thigh Muscle Volume and VO2MAX in Young Men. J Sports Sci Med. 2010 Sep 1;9(3):452-8. eCollection 2010.

  PMID: 24149640 RESULT

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Asisst. Prof.

Model Details: Initially, 30 male volunteers who were not actively engaged in sports were recruited for the study. After applying the exclusion criteria, which included a history of lower extremity injury (n = 4), respiratory disorders (n = 1) and refusal to participate (n = 1), a total of six individuals were excluded in the initial phase. Thus, the study commenced with 24 male participants. Each group consisted of eight participants who completed the protocol and final post-tests were conducted and analysed accordingly. All participants were healthy individuals who did not engage in regular physical activity. The study involved three exercise groups: The Control Group (CG); the Cycling with Blood Flow Restriction Group (CBFRG); Cycling Exercise Group (CEG)

Study Record Dates

• First Submitted: June 30, 2025
• First Posted: August 11, 2025
• Study Start: December 1, 2023
• Primary Completion: March 5, 2024
• Study Completion: March 5, 2024
• Last Updated: August 11, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL

Locations

TU (1)