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Recovery Following Acute Endurance Training

Not Applicable
Completed
Conditions
Continuous Running
High Intensity Interval Training
Control Condition
Interventions
Other: High Intensity Interval Training
Other: Control Trial
Other: Coninuous Running
Registration Number
NCT06043492
Lead Sponsor
University of Thessaly
Brief Summary

Aerobic capacity is critical for many athletes, especially for endurance athletes. Althgough several training methods are implemented by coaches to improve endurance performance, recovery following acute endurance training is not adequately studied. However, such information is crucial for coaches to effectively design the most favorable training program, to avoid muscle injuries and overtraining, and ultimately to improve performance of their athletes. This study aims to examine the acute effect of different continuous and HIIT training protocols on indices of metabolism, EIMD, neuromuscular fatigue and performance in middle- and long-distance runners.

Detailed Description

Aerobic capacity is critical for many athletes, especially for endurance athletes. Endurance training leads to cardiopulmonary and musculoskeletal adaptations, which in turn lead to improvement of endurance performance. Several training methods have been established for the improvement of aerobic capacity and performance, including long distance and low speed training, and high intensity interval training (HIIT). Training methods are used depending on the kind of endurance that aim to improve, and the specific characteristics and energy demands of the event. Especially regarding middle- and long-distance runners, the energy comes mainly from the oxidative system, however, the contribution of the glycolytic pathway is equally important. Thus, improvement mainly of the low-intensity endurance, but also high-intensity endurance is important for these athletes. Additionally, both continuous endurance and HIIT are effective training methods for improving cardiorespiratory and metabolic function, and athletic performance, while evidence also exists in favor of HIIT being more effective. Thus both training methods are used by coaches to improve aerobic capacity and performance of their athletes.

Coaches should be careful regarding the frequency of HIIT training during a microcycle, to provide adequate recovery between training sessions to avoid muscle injuries and overtraining. Existing evidence suggests that endurance exercise (continuous or HIIT) may result in exercise-induced muscle damage (EIMD), inflammatory responses, oxidative stress, and performance deterioration, yet, the timeframe of recovery of physiological and biochemical indices following different endurance training protocols has not been adequately studied. However, such information is crucial for coaches to effectively design the most favorable training program for their athletes.

This study aims to examine the acute effect of different continuous and HIIT training protocols on indices of metabolism, EIMD, neuromuscular fatigue and performance in middle- and long-distance runners.

According to a preliminary power analysis (a probability error of 0.05, and a statistical power of 80%), a sample size of 8 subjects per group was considered appropriate in order to detect statistically meaningful changes between groups. Thus, 10 men and female middle- and long-distance runners, will participate in the study.

The study will be performed in a randomized, cross over, repeated measures design. During their first 1st and 2nd visit, all participants will sign an informed consent form after they will be informed about all the benefits and risks of the study and they will fill in and sign a medical history questionnaire. Fasting blood samples will be collected in order to estimate muscle damage concentration markers. Participants will be instructed by a dietitian how to record a 7-days diet recalls to ensure that they do not consume to greater extent nutrients that may affect EIMD and fatigue (e.g. antioxidants, amino acids, etc.) and to ensure that the energy intake during the trials will be the same. Assessment of body mass and body height, body composition, and aerobic capacity (VO2max), will be performed. Using a photocells system, countermovement jump will be performed to assess jump height, and 30 sec Bosco test to assess mean jump height, peak power, mean power, and fatigue index. The peak concentric, eccentric and isometric isokinetic torque of the knee flexors and extensors, in both limbs will be evaluated on an isokinetic dynamometer at 60°/sec. Maximal voluntary isometric contraction (MVIC) of the knee extensors at 65o in both limbs, as well as the fatigue rate during MVIC through the percent drop of peak torque between the first and the last three seconds of a 10-sec MVIC, will also be evaluated. Afterwards, participants will be randomly assigned into, and perform one of the three different conditions of the study design: a) Continuous running (CT) for 40 min at lactic threshold, b) High intensity interval training (HIIT): 10x2min running at vVO2max with active recovery at 40% της VO2max (interval:recovery 1:1) with a load of 10% of body weight (BW), and c) control condition, no training (measurements only). The training protocols will be matched for mean power and total duration (Tschakert and Hofmann 2013). Prior and immediately after each experimental trial, delayed onset of muscle soreness (DOMS) in the knee flexors (KF) and extensors (KE) of both limbs, as well as blood lactate will be assessed. Additionally, DOMS of KF and KE, peak concentric, eccentric and isometric isokinetic torque, CMJ height, as well as mean jump height, peak power, mean power, and fatigue index during a 30 sec Bosco test, will be assessed 24h, 48h and 72h after the end of the trial. MVIC of the knee extensors of both limbs, as well as the fatigue rate during MVIC will also be assessed at 1h, 2h and 3h, as well as 24h, 48h, and 72h after the end of the trial. Creatine kinase will be assessed at 24h, 48h, and 72h after the end of the trial. The exact above procedures will be repeated by the participants during the remaining two experimental trials. A 2-weeks wash-out period will be implemented between trials.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
10
Inclusion Criteria
  • Middle- and long-distance runners
  • Absence of musculoskeletal injuries (≥ 6 months)
  • No use of drugs or ergogenic supplements (≥ 1 month)
  • Absense from eccentric exercise (≥ 3 days)
  • No alcohol or ergogenic drinks consumption before each training protocol
Exclusion Criteria
  • Musculoskeletal injury (< 6 months)
  • Use of drugs or ergogenic supplements (< 1 month)
  • Participation in eccentric exercise (< 3 days)
  • Alcohol or ergogenic drinks consumption before the training protocol

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
High Intensity Interval TrainingHigh Intensity Interval TrainingThe participants will perform an acute bout of high intensity interval training
Control TrialControl TrialThe participants will not perform any endurance exercise protocol
Coninuous RunningConinuous RunningThe participants will perform an acute bout of continuous running
Primary Outcome Measures
NameTimeMethod
Changes in peak power during a 30 sec Bosco testBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Peak power will be measured with a photocells system.

Changes in DOMSBaseline (pre), post-, 24 hours post-, 48 hours post-, 72 hours post-trial

DOMS of knee extensors and knee flexors of both lower extremities will be measured during palpation of the muscle belly and the distal region after performing three repetitions of a full squat.

Changes in Creatine kinase (CK)Baseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

CK will be measured in plasma using a Clinical Chemistry Analyzer with commercially available kits.

Changes in blood lactateBaseline (pre), 4 minutes post-trial

Lactate will be measured in capillary blood with a hand-portable analyzer.

Changes in squat jump heightBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Squat jump height will be measured with a photocells system.

Changes in mean jump height during a 30 sec Bosco testBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Mean jump height will be measured with a photocells system.

Changes in peak concentric torqueBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Concentric torque of the knee extensors and knee flexors will be measured on an isokinetic dynamometer.

Changes in peak eccentric torqueBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Eccentric torque of the knee extensors and knee flexors will be measured on an isokinetic dynamometer.

Changes in mean power during a 30 sec Bosco testBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Mean power will be measured with a photocells system.

Changes in maximal voluntary isometric contraction (MVIC)Baseline (pre), 1 hour post-, 2 hours post-, 3 hours post-, 24 hours post-, 48 hours post-, 72 hours post-trial

MVIC of the knee extensors and knee flexors will be measured on an isokinetic dynamometer.

Changes in fatigue rate during a 30 sec Bosco testBaseline (pre), 24 hours post-, 48 hours post-, 72 hours post-trial

Fatigue rate will be estimated through the persent drop in mean jump height between the first 5 jumps and the last 5 jumps.

Secondary Outcome Measures
NameTimeMethod
Body fatBaseline

Body fat will be measured by using Dual-emission X-ray absorptiometry.

Maximal oxygen consumption (VO2max)Baseline

VO2max will be measured by open circuit spirometry via breath by breath method during a graded treadmill running protocol.

Body weightBaseline

Body weight will be measured on a beam balance with stadiometer.

Body heightBaseline

Body height will be measured on a beam balance with stadiometer.

Body mass index (BMI)Baseline

BMI will be calculated from the ratio of body mass/ body height squared.

Lean body massBaseline

Lean body mass will be measured by using Dual-emission X-ray absorptiometry.

Dietary intakeBaseline

Dietary intake will be assessed using 7-day diet recalls.

Trial Locations

Locations (1)

Department of Physical Education and Sport Science, Uninersity of Thessaly

🇬🇷

Trikala, Thessaly, Greece

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