Influence of Menstrual Cycle Phase on Adaptations to Sprint Interval Training

NCT06744517 | Recruiting

• 1 other identifier: HSREB50581
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

Sprint interval training improves endurance performance and induces metabolic adaptations in muscle. Most research demonstrating these responses has been conducted in males, with limited studies evaluating changes to endurance performance and skeletal muscle oxidative capacity in females. Moreover, it is currently unknown if training in specific phases of the menstrual cycle influences adaptations to training. Thus, the purpose of the present study is to compare adaptations to 2 weeks of sprint interval training performed in the follicular vs. luteal phase of the menstrual cycle in healthy, eumenorrheic women.

Conditions

Healthy

Keywords

exercise; women

Outcome Measures

Primary Outcomes (1)

• Endurance performance

  Time to completion and average power output during a 250kJ time trial

  Before and after 2 weeks of exercise training

Secondary Outcomes (7)

• Skeletal muscle mitochondrial content

  Before and after 2 weeks of exercise training

• Skeletal muscle mitochondrial enzyme activity

  Before and after 2 weeks of exercise training

• Skeletal muscle capillarization

  Before and after 2 weeks of exercise training

• Skeletal muscle lipid content

  Before and after 2 weeks of exercise training

• Skeletal muscle protein synthesis

  Before and after 2 weeks of exercise training

Study Arms (2)

Follicular Phase Training

ACTIVE COMPARATOR

Exercise training in the follicular phase (\~days 1-14) of the participant's menstrual cycle

Other: Sprint Interval Training

Luteal Phase Training

EXPERIMENTAL

Exercise training in the luteal phase (\~days 15-28) of the participant's menstrual cycle

Other: Sprint Interval Training

Interventions

Sprint Interval Training OTHER

6 sessions of sprint interval training over 2 weeks. Each session involves 4-6 x 30 second Wingate sprints with 4 minutes of recovery in between on a stationary bike

Follicular Phase Training; Luteal Phase Training

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Participating in 150 min of moderate-vigorous physical activity/week
• VO2peak of 'good' or above based on American College of Sport Medicine (ACSM) normative values(greater than 35.0ml/kg/min)
• Body mass index (BMI) between 18-27 kg/m2
• Performing 2-4 structured exercise sessions/week.
• Weight stable (within ± 2kg for at least 6 months)
• Non-smoker
• Menstrual cycle length of 27-35 days
• Minimal menstrual cycle length variability (less than 3 days)
• Ovulating monthly evidenced by a positive urinary luteinizing hormone surge
• Blood progesterone concentration greater than 16 nmol/L.

You may not qualify if:

• Hormonal contraceptive use within the last 3 months
• Polycystic ovarian syndrome (PCOS) or endometriosis
• Failure to meet MC verification criteria.
• Diagnosed with cardiovascular or metabolic disease, hyper- or hypogonadism, and/or PCOS
• The use of medication for managing blood glucose or lipid metabolism
• Current use of oral contraceptives or use within the last 3 months
• Irregular menstrual cycles (\<27 days or \>35 days)
• Pregnant or post-partum in the last 12 months, lactating or breast feeding within 3 months of the start of study, or menopausal
• Recreational smoking tobacco
• Inability to perform the study exercise protocols or follow the pre-trial dietary or physical activity controls
• Taking medications affecting substrate metabolism (corticosteroids or nSAIDs)
• Actively engaging in a low-carbohydrate diet (e.g., ketogenic, Atkins)

Sponsors & Collaborators

• University of Toronto: lead

Study Sites (1)

Goldring Centre for High Performance Sport

Toronto, Ontario, M5S 2C9, Canada

RECRUITING

MeSH Terms

Conditions

Motor Activity

Interventions

High-Intensity Interval Training

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Central Study Contacts

Jenna Gillen Assistant Professor, PhD

CONTACT

4169783244; jenna.gillen@utoronto.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: December 16, 2024
• First Posted: December 20, 2024
• Study Start: January 1, 2025
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026
• Last Updated: April 29, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)