Aerobic Adaptations With Various Training Methods

Study Overview
=================
Brief Summary
-----------------
The goal of this intervention study is to compare the adaptations after a 6-week training period between an intense continuous and a high-intensity interval training program performed under iso-effort conditions on aerobic performance parameters in young healthy adults. The main question it aims to answer are if the intense continuous and a high-intensity interval training programs will induce similar adaptations in maximal (VO2max and PTV) and submaximal (critical velocity, lactate threshold parameters and running economy) aerobic performance parameters. Participants will be ere randomly assigned either to an intense continuous training group (CON) or to a high-intensity interval training group (INT). The training program will comprise of 14 training sessions performed over a 6-week period.

Detailed Description
-----------------
The aim of this study was to compare the adaptations after a 6-week training period between the intense continuous and the high-intensity interval training methods performed under iso-effort conditions on maximal (VO2max and PTV) and submaximal (critical velocity, lactate threshold parameters and running economy) aerobic performance parameters. A parallel group research design was used in the present study. Initially, 26 participants (10 males and 16 females), using stratified randomization (gender was the variable of stratification) were randomly assigned (1:1), according to a random-number table, either to an intense continuous training group (CON) or to a high-intensity interval training group (INT). The INT group trained using the interval method. During the exercise sessions the participants ran each bout at an intensity corresponding to 90% of PTV. PTV was used to prescribe the exercise intensity at the INT group. The duration of the running-bouts was equal to ¼ of the individual time to exhaustion at 90% of PTV (determined during the CV testing) followed by passive rest equal to 2/3 of exercise duration. The duration of the exercise-bouts was individualized based on the time to exhaustion at 90% of PTV to reduce the between subject's variability. The participants terminated each exercise session when an RPE value of 17 was reached. Running bout duration and intensity were adjusted after 7 training sessions (during the 3rd week) following a reassessment of the time to exhaustion at 90% of the new PTV achieved during mid-testing as a result of training. The CONT group trained using the continuous method. During the training sessions the participants ran with an intensity corresponding to -2,5% of CV until they reported a rating of 17 at the 6-20 Borg's scale. Running velocity was adjusted after 7 training sessions (during the 3rd week) after reassessment of CV. CV was used to determine the exercise intensity in the CONT group to ensure that all individuals would ran at the heavy intensity domain and be able to complete at least 15 min of continuous running, and to minimize the high inter-individual variations in endurance time at intensities near the upper limit of the heavy intensity domain. Using PTV to determine the intensity in the CONT group, would increase the possibility for trainees to exercise at different exercise intensity domains. During the experiment, participants will not perform any other form of training besides of that applied in the current study. VO2max, PTV, oxygen consumptions, heart rates and the velocities corresponding to the 1st and the 2nd lactate thresholds (LT1 and LT2), the velocity at 4 mmol/L of blood lactate concentration (v4mmol), running economy, and critical velocity (CV) will be measured before, after 7 training sessions (3rd week, two days after the 7th training session), and after the completion of training program.

Official Title
-----------------
Aerobic Adaptations Following Two Iso-effort Training Programs: An Intense Continuous and a High-intensity Interval

Conditions
-----------------
Healthy

Intervention / Treatment
-----------------
* Other: Interval training
* Other: Continuous training


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion criteria All participants should have been involved in low intensity continuous training, All participants should have been training 1-3 times per week for 30-45 min for at least three months. Exclusion criteria Not familiar with aerobic training Any health issues that did not allow participation in regular exercise training.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: A parallel group research design was used in the present study. Initially, 26 participants (10 males and 16 females), using stratified randomization (gender was the variable of stratification) were randomly assigned (1:1), according to a random-number table, either to an intense continuous training group (CON) or to a high-intensity interval training group (INT).
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Interval training<br>The interval group trained using the interval trainining method. | Other: Interval training<br>* The interval training group trained using the interval method. During the exercise sessions the participants ran each bout at an intensity corresponding to 90% of PTV. PTV was used to prescribe the exercise intensity at the INT group. The duration of the running-bouts was equal to ¼ of the individual time to exhaustion at 90% of PTV (determined during the CV testing) followed by passive rest equal to 2/3 of exercise duration. The duration of the exercise-bouts was individualized based on the time to exhaustion at 90% of PTV to reduce the between subject's variability. The participants terminated each exercise session when an RPE value of 17 was reached. Running bout duration and intensity were adjusted after 7 training sessions (during the 3rd week) following a reassessment of the time to exhaustion at 90% of the new PTV achieved during mid-testing as a result of training.<br>|
| Experimental: Continuous training<br>The continuous group trained using the continuous training method. | Other: Continuous training<br>* The continuous group trained using the continuous method. During the training sessions the participants ran with an intensity corresponding to -2,5% of CV until they reported a rating of 17 at the 6-20 Borg's scale. Running velocity was adjusted after 7 training sessions (during the 3rd week) after reassessment of CV. CV was used to determine the exercise intensity in the CONT group to ensure that all individuals would ran at the heavy intensity domain and be able to complete at least 15 min of continuous running, and to minimize the high inter-individual variations in endurance time at intensities near the upper limit of the heavy intensity domain. Using PTV to determine the intensity in the CONT group, would increase the possibility for trainees to exercise at different exercise intensity domains.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in maximal oxygen consumption | Maximal oxygen consumption in ml/kg/min | At the beginning of the training program, the 3rd week of training (after 7 training sessions), and the 7th week after the start of the intervention (after the completion of 6 weeks of training, 14 training sessions) | 
| Changes in peak treadmill velocity | Peak treadmill velocity using a maximal incremental test to exhaustion on a treadmill in km/h | At the beginning of the training program, the 3rd week of training (after 7 training sessions), and the 7th week after the start of the intervention (after the completion of 6 weeks of training, 14 training sessions) | 
| Changes in running velocities at the 1st and the 2nd lactate thresholds | Running velocities (km/h) at the 1st and the 2nd lactate thresholds by measuring the changes in blood lactate concentration during a maximal incremental test to exhaustion on a treadmill. | At the beginning of the training program, the 3rd week of training (after 7 training sessions), and the 7th week after the start of the intervention (after the completion of 6 weeks of training, 14 training sessions) | 
| Changes in critical velocity | Critical velocity (km/h) determined by having the participants ran until exhaustion at velocities corresponding to 90, 100, and 110% of peak treadmill velocity. Using linear regression analyses, the relationship between the distance covered at each run and the time to exhaustion was calculated. Τhe slope of the linear regression line was the critical velocity. | At the beginning of the training program, the 3rd week of training (after 7 training sessions), and the 7th week after the start of the intervention (after the completion of 6 weeks of training, 14 training sessions) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in running economy | Running economy determined by measuring the oxygen consumption (ml/kg/min) while running for 10 min at a velocity corresponding to 70% of the pre-training peak treadmill velocity | At the beginning of the training program and the 7th week after the start of the intervention (after the completion of 6 weeks of training, 14 training sessions) | 
| Changes in running velocity at a blood lactate concentration of 4 mmol/L | Running velocity (km/h) at a blood lactate concentration of 4 mmol/L determined by the individual relationship between lactate concentrations and running velocities during an incremental test by applying a nonlinear regression model. | At the beginning of the training program and the 7th week after the start of the intervention (after the completion of 6 weeks of training, 14 training sessions) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
maximal oxygen consumption, exercise, endurance