The Effects of Whey Protein Supplements on Markers of Exercise-induced Muscle Damage in Resistance-trained Individuals

Study Overview
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Brief Summary
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Intense exercise can bring about various side effects to one's body. Less range of motion, increased pain sensitivity, increased muscle swelling, and decreased muscle strength can occur immediately after exercise. These side effects can be referred to exercise induced muscle damage (EIMD) and can sometimes last many days. This study's goal is to evaluate the effects of various protein supplements on EIMD symptoms as well as on blood vessel health during the recovery period after muscle damaging exercise.

Detailed Description
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Eccentric exercise can result in exercise induced muscle damage (EIMD), which can cause an abundance of ultrastructural muscular disruption and pro-inflammatory and pro-oxidant activity in the body, leading to an impairment of muscular force production and range of motion, along with elevated pain sensitivity, increased swelling, and arterial stiffness. Pasture-raised dairy products, obtained from strictly grass-fed cows, have been shown to possess more anti-inflammatory-, antioxidant-, and antihypertensive-like biochemicals compared with conventional products (i.e., with a different nutrient composition from a diet rich in grains versus grasses). However, human research trials on these products, such as whey protein concentrate (WPC), are neglected. This study addresses this gap, with a double-blind, randomized, placebo-controlled trial that compares the effect of conventional WPC versus WPC supplementation reported to be derived from pasture-raised cows on vascular function and indirect markers of muscle damage and inflammation in response to eccentric EIMD in healthy, young, resistance-trained women and men. Thirty resistance-trained individuals will complete an intense EIMD bout consisting of eccentric barbell back squats and then will be assessed 24, 48, and 72 hours post-EIMD for muscle soreness, range of motion, maximal isometric voluntary contraction, peripheral fatigue via magnetic stimulation, countermovement jump, barbell back squat velocity, and vascular function (i.e., arterial stiffness via carotid femoral pulse wave velocity). Subjects will be grouped into a conventional WPC, pasture-raised WPC, and placebo supplementation group and consume their respective supplementation thrice daily immediately post-EIMD until the study's completion.

Official Title
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The Effects of Pasture-raised Versus Conventional Whey Protein Supplementation on Vascular Function and Markers of Exercise-induced Muscle Damage and Inflammation in Resistance-trained Individuals

Conditions
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Muscle Damage, Muscle Soreness

Intervention / Treatment
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* Dietary Supplement: Pasture-raised whey protein
* Dietary Supplement: Conventional whey protein
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women 18-40 years old ≥3 months uninterrupted training of ≥3 days/week of resistance training Self-reported to be healthy Exclusion Criteria: Not within defined age range History of allergy to dairy products History of experiencing pain while exercising in the lower extremities (i.e., hips/knees) Current use of anti-inflammatory/anti-pain medication (i.e., nonsteroidal anti-inflammatory drugs (NSAIDs) such as Tylenol, Advil, or Aleve Are pregnant or could possibly be pregnant by self-report People who answer 'yes' to any of the pre-participation screening questions on the PAR-Q questionnaire.

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

Sexes Eligible for Study
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All

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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pasture-raised whey protein<br>whey protein from strictly grass fed cows | Dietary Supplement: Pasture-raised whey protein<br>* 25 grams of protein delivered 3 times daily<br>* Other names: Premium Blend Protein, Pasture Raised, Grass Fed, unflavored, Muscle Feast, Nashport, OH, USA;|
| Experimental: Conventional whey protein<br>whey protein from conventional animal feeding operation | Dietary Supplement: Conventional whey protein<br>* 25 grams of protein delivered 3 times daily<br>* Other names: 100% Whey Protein Powder, unflavored, TGS Nutrition, Las Vegas, NV, USA;|
| Placebo Comparator: Placebo<br>Maltodextrin given in iso-caloric amounts to protein | Dietary Supplement: Placebo<br>* Iso-caloric placebo taken 3 times daily like the protein supplementation<br>* Other names: Maltodextrin, Bulk Supplements, Henderson, NV, USA;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Titin | Muscle damage assessment via urinary titin via ELISA (MBS2881644, Human Titin ELISA® Kit, MyBioSource.com, Inc., San Diego, USA). Units: pmol | Four days | 
| Isometric torque | Isometric torque assessment of right leg extensors will be conducted at a knee angle of 90 degrees using a calibrated load cell (model Z Tension Load Cell; Dillon, Fairmont, MN) Units: Nm | Four days | 
| Range of motion | Hamstring flexibility and stiffness will be measured using a sit-and-reach box (Lafayette Instrument Company, Lafayette, IN) test. Units: cm | Four days | 
| delayed onset muscle soreness | Visual analog scale of muscle soreness (delayed onset muscle soreness; DOMS) - Knee extensor soreness will be assessed using a visual analogue scale with no soreness indicated at one end (score 0) and unbearably painful at the other (score 100). Units: arbitrary units | Four days | 
| Pain pressure threshold | Muscle tenderness, known as pain pressure threshold, will be quantified using a digital algometer (Force One, Wagner Instruments, Greenwich, CT) on pre-marked sites at two specific points on the quadriceps (rectus femoris-RF and vastus lateralis-VL) and one on the calf (gastrocnemius-GM). Units: percentage change from baseline | Four days | 
| Peripheral Fatigue | Peripheral fatigue will be assessed via magnetic stimulation (Magstim 200-2; Jali Medical, Newton, MA, USA) of the femoral nerve, which will be used to elicit a quadriceps twitch. Units: Nm | Four days | 
| Countermovement Jump | A linear position transducer (GymAware Powertool; Kinetic Performance Technology, Canberra, Australia) interfaced with an iPad (Apple, CA, USA) will be used to calculate countermovement jump (CMJ) height. Units: cm | Four days | 
| Barbell back squat velocity | The mean velocity of the barbell will be measured using the linear position transducer as per the load velocity profile relationship. Units: m/s | Four days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial Stiffness | Utilizing carotid femoral pulse wave velocity via applanation tonometry, considered the non-invasive gold standard of central arterial stiffness, the ATCOR SphygmoCor® (Naperville, IL, USA) device will be utilized. Units: m/sec | Four days |