Effects of Polarized and Threshold Intensity Distribution Models on Race Time and Body Composition in Recreational Runners Aged 20-45 Years.

Universidad Pedagogica Nacional, Colombia

Status: Invitation-only

Conditions: Running Endurance; Running Performance; Physical Activity; Physical Activity in Adults; Physical Activity Intensity; Running

Treatments: Other: Threshold intensity distribution model; Other: Polarized intensity distribution model

Study type: Interventional

Funder types: Other

Identifiers

NCT07498608

340ETIC-020-2026

Details and patient eligibility

About

This study aims to compare the effects of two intensity distribution training (TID) models-polarized and threshold-on 5-km race time and body composition in recreational runners aged 20 to 45 years. Participants will be randomly assigned to one of two groups and will complete a 12-week structured training program. The primary outcome will be 5-km race time, while secondary outcomes will include changes in body composition. Assessments will be conducted before and after the intervention period.

Full description

This randomized controlled trial will investigate the effects of two different intensity distribution training (TID) models: polarized (POL) and threshold (THR), on race time and body composition in recreational runners.

A total of 40 participants aged between 20 and 45 years will be randomly assigned to either the POL group or the THR group. Both groups will complete a 12-week training intervention. The polarized model will emphasize a high volume of low-intensity training (Zone 1) with small amounts of high-intensity work (Zone 3), while the threshold model will include a greater proportion of training at moderate intensity (Zone 2).

The primary outcome will be 5-km race time measured in minutes/seconds. Secondary outcomes will include body composition variables such as body fat percentage and lean mass.

Assessments will be conducted at baseline and after the 12-week intervention. The study aims to determine whether polarized training produces superior improvements compared to threshold training in recreational runners.

Enrollment: 20 estimated patients

Sex: All

Ages: 20 to 45 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age between 20 and 45 years.
• 1 to 3 years of experience.
• Men's race time between 25:00 and 40:00.
• Women's race time between 28:00 and 43:00.
• Must reside in Bogotá or surrounding municipalities at an altitude of 2,640 meters above sea level.
• Must have a GPS device.

Exclusion criteria

• Having a chronic noncommunicable disease.
• Smoking or drinking alcohol.
• Having a musculoskeletal injury.
• Failing to sign the informed consent form.
• 10% attendance rate at training sessions.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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20 participants in 2 patient groups

Control

Active Comparator group

Treatment:

Other: Polarized intensity distribution model

Experimental

Experimental group

Treatment:

Other: Threshold intensity distribution model