NASM OPT for Pectoral Enhancement and Breast Firmness in Non-Athletic Women: An RCT

Efficacy of a 12-Week NASM Optimum Performance Training Program on Pectoral Muscle Strength, Breast Aesthetics, and Low Back Pain in Non-Athletic Women: A Randomized Controlled Trial

Status

Enrolling by invitation

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06977919

Acronym

BreastFirmne

Enrollment

120

Registered

2025-05-18

Start date

2025-05-01

Completion date

2025-09-30

Last updated

2025-05-18

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

Conditions

Low Back Pain, Muscle Weakness, Breast Sagging

Keywords

NASM OPT, Pectoral Muscles, Breast Firmness, Non-Athletic Women, Resistance Training

Brief summary

This RCT investigates a 12-week NASM OPT program targeting pectoral muscle strength, breast aesthetics (firmness, lift, chest circumference), and low back pain in 120 non-athletic women. The intervention group performed structured resistance training, while the control group engaged in general exercise. Outcomes included pectoral strength (dynamometer), aesthetic satisfaction (Likert scale), and functional performance (push-up test).

Detailed description

Participants were randomized to NASM OPT (3 weekly sessions: stabilization, strength, and hypertrophy phases) or general exercise (brisk walking/aerobics). Measurements at baseline and 12 weeks included pectoral strength, chest circumference, low back pain (VAS), and perceived breast aesthetics.

Interventions

BEHAVIORALNASM OPT Program

Three 60-minute weekly sessions for 12 weeks, progressing through stabilization (weeks 1-4), strength endurance (weeks 5-8), and hypertrophy (weeks 9-12) phases. Exercises included bench presses, chest flyes, and push-ups.

BEHAVIORALGeneral Exercise

Three 60-minute weekly sessions of brisk walking and light aerobics without targeted resistance training.

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

SINGLE (Outcomes Assessor)

Masking description

Single-blind (outcome assessors only; participants/instructors unblinded due to intervention nature).

Eligibility

Sex/Gender

FEMALE

Age

20 Years to 45 Years

Healthy volunteers

Yes

Inclusion criteria

* Non-athletic women (no exercise in prior 6 months). * Interest in improving chest aesthetics. * No musculoskeletal injuries.

Exclusion criteria

* Pregnancy * Chronic illness * Exercise contraindications

Design outcomes

Primary

Measure	Time frame	Description
Pectoral Strength	Baseline, 12 weeks	Kilogram (kg); handheld dynamometer
Perceived Breast Firmness/Lift	Baseline, 12 weeks	5-point Likert scale
Chest Circumference	Baseline, 12 weeks	Centimeter (cm)

Secondary

Measure	Time frame	Description
Aesthetic Satisfaction	Baseline, 12 weeks (post-intervention)	5-point Likert scale
Functional Performance	Baseline, 12 weeks (post-intervention)	30-second push-up test
Low Back Pain	Baseline, 12 weeks (post-intervention)	VAS, 0-10 cm

Countries

Iran

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026