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Cluster Training With Blood Flow Restriction in Competitive 200-m Freestyle Swimmers

Cluster Training With Blood Flow Restriction and 200-m Freestyle Performance, FGF-2, and VEGF-A Responses in Competitive Swimmers: A Matched Controlled Study

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07786129
Acronym
BFR-CLUSTER-SW
Enrollment
20
Registered
2026-08-25
Start date
2026-01-15
Completion date
2026-06-15
Last updated
2026-08-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Athletic Performance, Exercise Training

Keywords

Blood Flow Restriction, Cluster Training, Competitive Swimming, 200-m Freestyle, FGF-2, VEGF-A

Brief summary

This study evaluated whether adding blood flow restriction (BFR) to cluster-based training could improve swimming performance and selected physiological responses in competitive swimmers. Twenty competitive swimmers were assigned using a matched, non-randomized design to either an experimental group performing cluster training combined with BFR or a control group performing the same cluster training without BFR. The intervention lasted 8 weeks, with five training sessions per week. The primary outcome was 200-m freestyle performance time. Secondary outcomes included serum concentrations of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor-A (VEGF-A), standing long jump performance, mean 50-m split time during a 150-m swimming test, and repetitions completed during a cadence-controlled Burpee test. The study was designed to determine whether BFR provided additional performance and physiological benefits beyond cluster training alone.

Detailed description

Blood flow restriction (BFR) training is a training method in which pneumatic cuffs are applied proximally to the limbs to partially restrict vascular flow during exercise. Cluster training divides traditional exercise sets into smaller clusters of repetitions separated by short intra-set recovery periods. Combining these two approaches may increase the physiological stimulus of training while allowing repeated high-quality exercise efforts. This controlled, non-randomized matched-intervention study included 20 competitive 200-m freestyle swimmers. Participants were matched according to baseline 200-m freestyle performance, sex, and standing long jump distance and were assigned to one of two groups. The experimental group completed cluster training combined with BFR, whereas the control group completed cluster training without BFR. The training intervention lasted 8 weeks and consisted of five 90-minute training sessions per week. Sessions included a standardized warm-up, a main training component, and a cool-down. Overall cardiovascular training intensity was prescribed relative to individual maximal heart rate, and cluster-based resistance exercises incorporated short intra-set recovery intervals. BFR was applied only in the experimental group during selected dry-land cluster exercises using pneumatic cuffs positioned proximally on the upper arms and thighs. The cuffs remained inflated during exercise execution and short intra-set recovery periods and were deflated during the main inter-set recovery periods. The primary outcome was change in 200-m freestyle performance time from baseline to the end of the 8-week intervention. Secondary outcomes included serum FGF-2 and VEGF-A concentrations, standing long jump distance, mean 50-m split time during a maximal 150-m swimming test, and performance in a cadence-controlled Burpee test. Blood samples were collected under standardized resting conditions to assess serum FGF-2 and VEGF-A concentrations. The main objective was to determine whether the addition of BFR to cluster training was associated with greater improvements in swimming performance, selected physical-performance outcomes, and serum angiogenesis-related biomarkers compared with cluster training alone.

Interventions

BEHAVIORALCluster Training With Blood Flow Restriction

An 8-week cluster-training program performed five sessions per week, with blood flow restriction applied during selected dry-land cluster exercises using pneumatic cuffs positioned proximally on the upper arms and thighs.

BEHAVIORALCluster Training Alone

An 8-week cluster-training program performed five sessions per week without blood flow restriction.

Sponsors

Saif Rasheed Ghanim
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE

Intervention model description

Participants were assigned to two parallel groups using a non-randomized matched-allocation approach. The experimental group received cluster training combined with blood flow restriction, whereas the control group received cluster training alone.

Eligibility

Sex/Gender
ALL
Age
17 Years to 20 Years
Healthy volunteers
Yes

Inclusion criteria

Competitive 200-m freestyle swimmers aged 17-20 years. At least 2 years of structured swimming training experience. Free from musculoskeletal injury for at least 6 months before enrollment. No previous regular experience with blood flow restriction training. Willing and able to complete the 8-week training intervention and all study assessments.

Exclusion criteria

History of cardiovascular, metabolic, thrombotic, or other vascular conditions that could contraindicate blood flow restriction exercise. Current use of medications known to affect vascular tone or blood coagulation. Musculoskeletal injury or medical condition preventing participation in maximal swimming or dry-land training. Attendance below 85% of the scheduled intervention sessions.

Design outcomes

Primary

MeasureTime frameDescription
Change in 200-m Freestyle Performance TimeBaseline and post-intervention at 8 weeksPerformance was assessed during a maximal 200-m freestyle swim in a standard 50-m pool using an electronic timing system with a precision of 0.01 s. Lower values indicate faster performance. The primary outcome was the change in performance time from baseline to the end of the 8-week intervention.

Countries

Iraq

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 27, 2026