Recovery of Performance, Muscle Damage and Neuromuscular Fatigue Following Muscle Power Training

Study Overview
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Brief Summary
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Muscle power is one of the most important parameters in almost every athletic action, and expresses the ability of the human muscle to produce great amounts of force with the greatest possible speed. Thus, muscle power is critical for high performance in athletic actions such as jumping, throwing, change of direction and sprinting. For enhancing their muscle power, athletes comprise several resistance training programs as part of their training. Muscle power training comprises of eccentric muscle actions, and the magnitude of these actions depend on the emphasis that is given on the concentric or eccentric action, respectively, of the muscles during the exercises. However, eccentric muscle action, especially when unaccustomed, can lead to exercise-induced muscle damage (EIMD), and deterioration of muscle performance. Despite the fact that muscle power training comprises eccentric muscle actions, and consequently can lead to muscle injury and muscle performance reduction during the following days, the recovery kinetics after acute muscle power training have not been adequately studied. However, information regarding the recovery of the muscles after a power training protocol, is critical for the correct design of a training microcycle, and the reduction of injury risk. The aim of the present study is to investigate the muscle injury provoked after acute muscle power training using three different power training exercise protocols. Additionally, we will examine the effect of these protocols on muscle performance and neuromuscular fatigue indices.

Detailed Description
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Muscle power is one of the most important parameters in almost every athletic action, and expresses the ability of the human muscle to produce great amounts of force with the greatest possible speed. Thus, muscle power is critical for high performance in athletic actions such as jumping, throwing, change of direction and sprinting. For enhancing their muscle power, athletes comprise several resistance training programs as part of their training. Core exercises as long as Olympic lifting has been used in muscle power training. The loads that are applied regarding the accomplishment of the most favorable power production are varying. Training load of 0% 1RM favored power production at the countermovement squat jump, while loads of 56% 1rm and 80% 1RM, favored the power production at squat and hang clean, respectively. Additionally, In the recent years, accentuated eccentric training has been proposed as a new training method for the enhancement of muscle power. This method emphasizes the eccentric component of the muscle contraction, and there is evidence supporting the greater production of muscle force after accentuated eccentric training compared with the typical resistance exercise training method. Taking the above into consideration, muscle power training comprises of eccentric muscle actions, and the magnitude of the eccentric component depends on the emphasis that is given on the concentric or eccentric action, respectively, of the muscles during the exercises. However, eccentric muscle action, especially when unaccustomed, can lead to exercise-induced muscle damage (EIMD). Although concentric and isometric exercise may also lead to muscle injury, the amount of damage after eccentric muscle contractions is greater. EIMD, amongst others, is accompanied by increased levels of creatine kinase (CK) into the circulation, increased delayed onset of muscle soreness (DOMS), reduction of force production, reduction of flexibility speed. Despite the fact that muscle power training comprises eccentric muscle actions, and consequently can lead to muscle injury and muscle performance reduction during the following days, the recovery kinetics after acute muscle power training protocols have not been adequately studied. However, information regarding the recovery of the muscles after a power training protocol, is critical for the correct design of a training microcycle, and the reduction of injury risk. The aim of the present study is to investigate the muscle injury provoked after muscle acute power training using three different power training exercise protocols. Additionally, the effect of these protocols on muscle performance and neuromuscular fatigue indices will be examined.

Official Title
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Investigation on the Recovery Kinetics of Performance, Muscle Damage and Neuromuscular Fatigue Indicators, Following Different Protocols for Muscle Power Development

Conditions
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Power Training Exercise Protocols

Intervention / Treatment
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* Other: Core exercises protocol
* Other: Structural exercises protocol
* Other: Accentuated eccentric load exercises protocol
* Other: Control condition


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: No recent history of musculoskeletal injury No use of ergogenic supplements and drugs No use of anti-inflammatory and antioxidant supplements (> 6 months) No participation at intense eccentric exercise for at least 3 days before protocols Exclusion Criteria: Recent history of musculoskeletal injury Use of ergogenic supplements and drugs Use of anti-inflammatory and antioxidant supplements (< 6 months) Participation at intense eccentric exercise for at least 3 days before protocols

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Each participant will perform in a random order all four different experimental conditions
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Core exercises protocol<br>Participants will perform 4 core exercises | Other: Core exercises protocol<br>* Participants will perform: Squats, 4 sets of 5 repetitions at 60% 1RM Deadlifts, 4 sets of 5 repetitions at 60% 1RM Lunges, 4 sets of 5 repetitions at 60% 1RM Step ups, 4 sets of 5 repetitions at 60% 1RM<br>|
| Experimental: Structural exercises protocol<br>Participants will perform 4 structural (Olympic lifting) exercises | Other: Structural exercises protocol<br>* Participants will perform: Snatch, 4 sets of 5 repetitions at 60% 1RM Hang clean, 4 sets of 5 repetitions at 60% 1RM Push jerk, 4 sets of 5 repetitions at 60% 1RM Split push jerk, 4 sets of 5 repetitions at 60% 1RM<br>|
| Experimental: Accentuated eccentric load exercises protocol<br>Participants will perform 4 exercises with eccentric loading | Other: Accentuated eccentric load exercises protocol<br>* Participants will perform: Deadlifts - squat jump, 4 sets of 5 repetitions at 30% body mass (BM) Step down - squat jump, 4 sets of 5 repetitions at 30% BM Step down - lunges, 4 sets of 5 repetitions at 30% BM Hip thrusts, 4 sets of 5 repetitions at 30% BM<br>|
| Other: Control condition<br>Participants will perform all the measurements that are comprised in the experimental conditions without performing any exercise protocol | Other: Control condition<br>* Participants will perform all the measurements that are comprised in the experimental conditions without performing any exercise protocol<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change on delayed onset of muscle soreness (DOMS), in the knee flexors (KF) and extensors (KE) of both limbs | Participants will perform three repetitions of a full squat movement, and rate their soreness level in knee flexors and extensors on a visual analog scale from 1 to 10 (VAS, with no pain at one end and extremely sore at the other), using palpation of the belly and the distal region of relaxed knee extensors and flexors. | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on countermovement jump (CMJ) height | CMJ height will be measured in 3 maximal efforts (the best jump will be recorded) on an Ergojump contact platform | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on isometric peak torque of the knee extensors (KE) | Isometric peak torque of the KE will be measured on an isokinetic dynamometer at 60◦/sec | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on isometric peak torque of the knee flexors (KF) | Isometric peak torque of the KF will be measured on an isokinetic dynamometer at 60◦/sec | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on concentric isokinetic peak torque of the knee extensors (KE) | Concentric peak torque of the KE will be measured on an isokinetic dynamometer at 60◦/sec | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on concentric isokinetic peak torque of the knee flexors (KF) | Concentric peak torque of the KF will be measured on an isokinetic dynamometer at 60◦/sec | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change one eccentric isokinetic peak torque of the knee extensors (KE) | Eccentric peak torque of the KE will be measured on an isokinetic dynamometer at 60◦/sec | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on eccentric isokinetic peak torque of the knee flexors (KF) | Eccentric peak torque of the KF will be measured on an isokinetic dynamometer at 60◦/sec | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on the concentration of plasma CK activity | Plasma CK activity will be measured with a biochemical analyzer | Prior to, immediately after, 1, 2, 3 days after the end of the experimental protocol | 
| Change on the concentration of blood lactate | Lactate will be measured with a portable lactate analyzer using capillary blood | Prior to, and immediately after the end of the experimental protocol |