Immediate, Residual, and Cumulative Effects of Fartlek, Hill Circuit, and Roll-On Training in Long-Distance Runners (IRCT-LDR)

Immediate, Residual, and Cumulative Effects of Fartlek, Hill Circuit, and Roll-On Training Modalities: A Comprehensive Examination of Conditioning in Long-Distance Runners

This randomized controlled trial will compare Fartlek, hill circuit, and roll-on training in well-trained long-distance runners. Twenty-one eligible runners will be randomly assigned to one of three training groups and will complete a 12-week intervention comprising 24 prescribed training sessions. The study will evaluate immediate responses to conditioning, 24-hour recovery responses, and cumulative changes in running performance, aerobic fitness, and training-related responses. Outcomes will include heart rate, blood lactate concentration, rating of perceived exertion, delayed-onset muscle soreness, recovery and wellness indicators, internal training load, 5-km time-trial performance, and VO₂max. The findings will provide evidence regarding the comparative responses to these three conditioning modalities in well-trained long-distance runners.

Study Overview

• Status: Not yet recruiting
• Conditions: Long Distance Running
• Intervention / Treatment: Behavioral: Fartlek training; Behavioral: Hill Circuit; Behavioral: Roll-On

Detailed Description

Long-distance running places substantial physiological and mechanical demands on athletes. Appropriate conditioning is therefore important for developing the capacity to tolerate training stress, recover effectively, and maintain or improve running performance. Different conditioning modalities may impose distinct physiological and mechanical demands, which may result in differences in immediate exercise responses, post-exercise recovery, training load, and longer-term adaptation.

This randomized controlled trial will compare three conditioning modalities. Fartlek training, hill circuit training, and roll-on training in well-trained long-distance runners. Twenty-one eligible runners will be randomly allocated to one of three parallel training groups: the Fartlek Training Group, Hill Circuit Training Group, or Roll-On Training Group. Each group will complete its assigned conditioning modality for 12 weeks, comprising 24 prescribed training sessions.

The study will examine three dimensions of response to conditioning. Immediate responses will include physiological and perceptual responses measured during or immediately after training. Residual responses will focus on recovery-related responses during the 24 hours following conditioning sessions. Cumulative responses will examine changes that develop over repeated exposure to the training intervention, including changes in running performance and aerobic fitness.

Repeated measurements will be collected throughout the intervention to characterize responses to the three conditioning modalities. Measures will include heart rate, blood lactate concentration, rating of perceived exertion, delayed-onset muscle soreness, recovery and wellness indicators, internal training load, 5-km time-trial performance, and VO₂max. Training-load measures will be derived from session rating of perceived exertion and session duration and will be used to characterize the training demands accumulated during the intervention.

The study will compare the response patterns among the three intervention groups to determine whether Fartlek, hill circuit, or roll-on training produces different immediate, residual, and cumulative responses in well-trained long-distance runners. The findings are intended to contribute evidence for the selection and progression of conditioning modalities while considering training stimulus, recovery, and performance-related responses.

• Study Type: Interventional
• Enrollment (Estimated): 21
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Awoke Tibebu, MSc.; Phone Number: +251912073305; Email: awoket27@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

Male long-distance runners aged 18-25 years VO₂max greater than 60 mL/kg/min Weekly training volume of at least 60 km Training experience of at least 4 years Mercier score greater than 600 Currently engaged in regular long-distance running training Willing to participate in the 12-week training intervention Able to complete all required testing and monitoring procedures Provides written informed consent to participate in the study

Exclusion Criteria:

Current musculoskeletal injury that prevents participation in training or testing Known cardiovascular, respiratory, metabolic, or other medical condition that limits strenuous exercise Current illness or condition that prevents participation in the intervention Use of medication or other treatment that may substantially affect exercise performance or physiological responses Failure to meet the required training or eligibility criteria Planned absence that would prevent adequate participation in the intervention Withdrawal of informed consent Any condition identified by the research team that makes continued participation unsafe

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Fartlek Training Group (FTG); A structured Fartlek running training intervention administered for 12 weeks to trained long-distance runners. The intervention consists of planned variable-intensity running bouts with prescribed duration, repetitions, running intensity, recovery periods, and progressive workload according to the study protocol. Training sessions will be supervised and standardized across participants.	Behavioral: Fartlek training; A structured variable-intensity running intervention administered for 12 weeks to trained long-distance runners. Each prescribed session includes standardized warm-up and cool-down periods, alternating faster and slower running at prescribed intensities, and prescribed recovery periods. Running duration, intensity, repetitions, recovery intervals, and workload progression are standardized according to the study protocol. Training sessions are supervised, and exercise intensity is monitored using heart rate, rating of perceived exertion, running pace, and prescribed workload.
Experimental: Hill Circuit Training Group (HCTG); Participants assigned to the Hill Circuit Training Group (HCTG) will receive the prescribed Hill Circuit training intervention during the 12-week randomized controlled trial. The intervention consists of structured hill-running and circuit-based training designed for trained long-distance runners. Training intensity, duration, repetitions, recovery periods, and progression will be prescribed according to the study protocol.	Behavioral: Hill Circuit; A structured hill-running and circuit-based training intervention administered for 12 weeks to trained long-distance runners. Each prescribed session includes standardized warm-up and cool-down periods, repeated uphill running bouts, running-based circuit exercises, and prescribed recovery intervals. Hill gradient, running duration, repetitions, exercise intensity, recovery intervals, and workload progression are standardized according to the study protocol. Exercise intensity is monitored using heart rate, rating of perceived exertion, running pace, and prescribed workload.
Experimental: Roll-On Training Group (ROTG); Participants assigned to the Roll-On Training Group (ROTG) will receive the prescribed Roll-On training intervention during the 12-week randomized controlled trial. The intervention consists of structured progressive running sessions designed for trained long-distance runners. Training intensity, duration, repetitions, recovery periods, and progression will be prescribed according to the study protocol.	Behavioral: Roll-On; A structured progressive running intervention administered for 12 weeks to trained long-distance runners. Each prescribed session includes standardized warm-up and cool-down periods, controlled running with planned gradual increases and decreases in running speed, and prescribed recovery periods where applicable. Running duration, speed progression, intensity, repetitions, recovery intervals, and workload progression are standardized according to the study protocol. Exercise intensity is monitored using heart rate, rating of perceived exertion, running pace, and prescribed workload.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
5-km Time-Trial Performance	Change in 5-km time-trial completion time from baseline to Week 6 and Week 12, comparing the Fartlek Training Group (FTG), Hill Circuit Training Group (HCTG), and Roll-On Training Group (ROTG).	Baseline week 6 and Week 12

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
VO₂max	Change in maximal oxygen uptake (VO₂max), measured in mL/kg/min, from baseline to Week 6 and Week 12, comparing FTG, HCTG, and ROTG.	Baseline, Week 6, and Week 12
Blood Lactate Concentration	Change in blood lactate concentration, measured in mmol/L, immediately following prescribed conditioning sessions to characterize the acute physiological response to Fartlek, Hill Circuit, and Roll-On training.	Immediately pre-training and post-training during intervention sessions in Weeks 1-12
Rating of Perceived Exertion (RPE)	Session rating of perceived exertion will be measured using the OMNI perceived-exertion scale immediately following each conditioning session.	Immediately after each training session during Weeks 1-12
Heart Rate Response	Change in average and maximum heart rate during prescribed conditioning sessions to characterize the acute cardiovascular response to Fartlek, Hill Circuit, and Roll-On training.	During each training session during Weeks 1-12
Complete Blood Count (CBC)	Change in selected hematological parameters, including hemoglobin, hematocrit, red blood cell count parameters.	Baseline, Week 6, and Week 12
5-km Performance Score	Change in performance score calculated using the applicable World Athletics scoring table based on 5-km time-trial performance from baseline to Week 12, comparing FTG, HCTG, and ROTG.	Baseline and Week 12

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Delayed-Onset Muscle Soreness (DOMS)	Change in self-reported muscle soreness following each prescribed conditioning session to assess post-exercise muscular recovery.	Immediately post-training and 24 hours after each conditioning session during Weeks 1-12
Recovery and Wellness	Change in recovery and wellness indicators, including sleep duration, sleep quality, fatigue, stress, mood, and overall wellness score, assessed following conditioning sessions.	Before and 24 hours after each conditioning session during Weeks 1-12
Acute Training Load	Weekly acute internal training load calculated from accumulated session training loads, where session training load is calculated as session duration multiplied by session rating of perceived exertion (sRPE).	Weeks 1-12
Chronic Training Load	Chronic internal training load calculated as the rolling 4-week average of weekly training load during the intervention.	Weeks 4-12
Training Monotony	Weekly training monotony calculated as the mean daily training load divided by the standard deviation of daily training load within each training week.	Weeks 1-12
Training Strain	Weekly training strain calculated as weekly training load multiplied by training monotony during the 12-week intervention.	Weeks 1-12
Freshness Index	Weekly freshness index calculated as chronic training load minus acute training load to characterize changes in training readiness during the intervention.	Weeks 1-12
Acute:Chronic Workload Ratio (ACWR)	Weekly acute:chronic workload ratio calculated as acute training load divided by chronic training load during the intervention.	Weeks 4-12

Collaborators and Investigators

• Sponsor: Debre Markos University
• Collaborators: Bahir Dar University
• Investigators: Study Director: Alemayehu, PHd, University of Gonder; Study Chair: Gashaw, PHd, Bahir Dar University

Study record dates

Study Major Dates

• Study Start (Estimated): September 21, 2026
• Primary Completion (Estimated): September 24, 2026
• Study Completion (Estimated): November 26, 2026

Study Registration Dates

• First Submitted: August 17, 2026
• First Submitted That Met QC Criteria: August 20, 2026
• First Posted (Actual): August 25, 2026

Study Record Updates

• Last Update Posted (Actual): August 26, 2026
• Last Update Submitted That Met QC Criteria: August 25, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Fartlek Training; Hill Circuit Training; Roll-On Training
• Other Study ID Numbers: IRERC-19-2025; bdu1500226 (Other Identifier: Bahir Dar University)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: State that de-identified individual participant data and supporting information will be available upon reasonable request, subject to ethical approval and protection of participant confidentiality.
• IPD Sharing Time Frame: After publication of the primary results.
• IPD Sharing Access Criteria: Access to individual participant data (IPD) and supporting information will be provided to qualified researchers whose proposed use is scientifically sound and consistent with the informed consent and ethical approvals of the study. Researchers may request access to de-identified IPD, the study protocol, statistical analysis plan (SAP), informed consent form (ICF), clinical study report (CSR), and analytic code, as applicable. Requests will be reviewed by the study investigators and/or the responsible institutional research ethics authority. Approved data will be shared through a secure data-sharing mechanism following execution of an appropriate data-use agreement. Data will not include direct participant identifiers.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No