Supplementation
Randomized Controlled Trial
2015
Collagen peptide supplementation in combination with resistance training improves body composition and increases muscle strength in elderly sarcopenic men
By Denise Zdzieblik and Steffen Oesser
British Journal of Nutrition, 114(8), pp. 1237-1245
<h2>Abstract</h2>
<p>This <a href="/terms/randomized-controlled-trial/" class="term-link" data-slug="randomized-controlled-trial" title="randomized controlled trial">randomized controlled trial</a> by Zdzieblik and Oesser (2015) investigated the effects of collagen peptide supplementation combined with resistance training on body composition, muscle strength, and functional capacity in elderly sarcopenic men. Fifty-three men (mean age 72 years) with age-related muscle loss were assigned to either 15g of collagen peptides or placebo daily for 12 weeks, with both groups participating in a standardized resistance training program three times per week.</p>
<p>The collagen peptide group demonstrated significantly greater increases in <a href="/terms/lean-body-mass/" class="term-link" data-slug="lean-body-mass" title="fat-free mass">fat-free mass</a> (+4.2 kg vs. +2.9 kg), greater decreases in fat mass (-5.4 kg vs. -3.5 kg), and superior gains in muscle strength compared to placebo [1]. These findings suggest that collagen peptide supplementation provides meaningful benefits beyond resistance training alone in this population — a clinically important finding given the public health burden of sarcopenia.</p>
<p>The proposed mechanisms include collagen peptides providing specific amino acids (glycine, proline, hydroxyproline) that serve as substrates for collagen synthesis in muscle <a href="/terms/connective-tissue/" class="term-link" data-slug="connective-tissue" title="connective tissue">connective tissue</a>, tendons, and cartilage, potentially enhancing the mechanical transmission of force and reducing exercise-related joint discomfort that may otherwise limit training intensity [2].</p>
<p><strong>Keywords</strong>: collagen peptides, sarcopenia, resistance training, body composition, elderly, connective tissue, lean mass</p>
<h2>Introduction</h2>
<p>Sarcopenia — the progressive loss of skeletal muscle mass and strength with aging — represents one of the most consequential physiological changes accompanying advancing age. Affecting an estimated 10-40% of older adults depending on diagnostic criteria, sarcopenia is associated with falls, fractures, functional decline, loss of independence, and increased mortality [1]. Resistance training is the most evidence-supported intervention for attenuating sarcopenic muscle loss, but nutritional co-interventions that amplify training-induced adaptations are of considerable practical interest.</p>
<p>Collagen is the most abundant protein in the human body, constituting approximately 30% of total body protein and forming the structural matrix of tendons, ligaments, cartilage, bone, and the extracellular components of skeletal muscle. Unlike globular proteins such as <a href="/terms/whey-protein/" class="term-link" data-slug="whey-protein" title="whey">whey</a> or <a href="/terms/casein/" class="term-link" data-slug="casein" title="casein">casein</a> that are enriched in <a href="/terms/essential-amino-acids/" class="term-link" data-slug="essential-amino-acids" title="essential amino acids">essential amino acids</a>, collagen has a distinctive amino acid composition dominated by glycine (approximately 33%), proline (approximately 22%), and hydroxyproline (approximately 14%), with relatively low content of essential amino acids including very low <a href="/terms/leucine/" class="term-link" data-slug="leucine" title="leucine">leucine</a> [2].</p>
<p>This compositional profile initially led researchers to discount collagen protein as a nutritionally inferior source for <a href="/terms/muscle-protein-synthesis/" class="term-link" data-slug="muscle-protein-synthesis" title="muscle protein synthesis">muscle protein synthesis</a> compared to leucine-rich complete proteins. However, this perspective may underestimate collagen's role in the <a href="/terms/connective-tissue/" class="term-link" data-slug="connective-tissue" title="connective tissue">connective tissue</a> matrix that supports skeletal muscle function. Muscle force transmission to the skeleton requires intact myotendinous junctions and fascial networks, and the rate of collagen synthesis in these structures is sensitive to <a href="/terms/mechanical-tension/" class="term-link" data-slug="mechanical-tension" title="mechanical loading">mechanical loading</a> — and potentially to precursor amino acid availability.</p>
<p>The hypothesis underlying the Zdzieblik and Oesser study was that supplemental collagen peptides might provide enhanced substrate for connective tissue remodeling in response to resistance training, improving both the structural integrity of the musculoskeletal system and potentially reducing exercise-related joint discomfort that can limit training adherence and intensity in older adults with pre-existing joint degeneration [3].</p>
<p>Collagen peptides (hydrolyzed collagen) represent a processed form in which collagen is partially hydrolyzed into smaller peptides of 2-10 kDa, enhancing gastrointestinal absorption compared to intact collagen protein. Specific bioactive collagen peptides have been identified in plasma after oral ingestion, suggesting that some peptide sequences survive digestion and may have direct biological effects on chondrocytes and fibroblasts beyond simple amino acid provision [4].</p>
<h2>Methods</h2>
<h3>Study Design</h3>
<p>This double-blind, <a href="/terms/randomized-controlled-trial/" class="term-link" data-slug="randomized-controlled-trial" title="randomized controlled trial">randomized controlled trial</a> enrolled 53 elderly men (mean age 72 ± 5 years) who met diagnostic criteria for sarcopenia based on the European Working Group on Sarcopenia in Older People (EWGSOP) definition: low skeletal muscle mass index combined with low muscle strength or low physical performance. Participants were randomized to either 15g of specific collagen peptides (BODYBALANCE, Gelita AG) dissolved in non-caloric fluid or a calorie-matched placebo daily for 12 weeks [1].</p>
<h3>Resistance Training Protocol</h3>
<p>All participants completed a standardized resistance training program three sessions per week for the full 12 weeks. The program included compound lower body exercises (leg press, leg extension, leg curl, calf raise) and upper body exercises (bench press, lat pulldown, seated row) performed at 60-80% of <a href="/terms/one-repetition-maximum/" class="term-link" data-slug="one-repetition-maximum" title="one-<a href="/terms/repetition-maximum/" class="term-link" data-slug="repetition-maximum" title="repetition maximum">repetition maximum</a>">one-repetition maximum</a> (1RM). <a href="/terms/progressive-overload/" class="term-link" data-slug="progressive-overload" title="Progressive overload">Progressive overload</a> was applied as participants adapted. This controlled training stimulus was critical for isolating the supplementation effect, as it ensured both groups received identical <a href="/terms/mechanical-tension/" class="term-link" data-slug="mechanical-tension" title="mechanical loading">mechanical loading</a> [2].</p>
<h3>Supplement Timing</h3>
<p>The collagen peptide supplement was consumed 30-60 minutes prior to each resistance training session on <a href="/terms/training-frequency/" class="term-link" data-slug="training-frequency" title="training days">training days</a>. On non-training days, supplementation was taken at a consistent time with a meal. Total daily dose was 15g, delivered as a single serving. The protocol was designed to maximize the local availability of collagen precursor amino acids at the time of mechanically stimulated <a href="/terms/connective-tissue/" class="term-link" data-slug="connective-tissue" title="connective tissue">connective tissue</a> synthesis.</p>
<h3>Outcome Measures</h3>
<table>
<thead>
<tr>
<th>Measure</th>
<th>Assessment Tool</th>
<th>Timepoint</th>
</tr>
</thead>
<tbody>
<tr>
<td><a href="/terms/lean-body-mass/" class="term-link" data-slug="lean-body-mass" title="Fat-free mass">Fat-free mass</a></td>
<td>DXA (dual-energy X-ray absorptiometry)</td>
<td>Baseline, 12 weeks</td>
</tr>
<tr>
<td>Fat mass</td>
<td>DXA</td>
<td>Baseline, 12 weeks</td>
</tr>
<tr>
<td>Leg press strength</td>
<td>1RM test</td>
<td>Baseline, 12 weeks</td>
</tr>
<tr>
<td>Leg extension strength</td>
<td>1RM test</td>
<td>Baseline, 12 weeks</td>
</tr>
<tr>
<td>Physical function</td>
<td>Timed Up-and-Go (TUG) test</td>
<td>Baseline, 12 weeks</td>
</tr>
</tbody>
</table>
<h3>Statistical Analysis</h3>
<p>Between-group differences in changes from baseline were analyzed using mixed-model repeated measures ANOVA with treatment group and time as factors. Effect sizes were calculated as <a href="/terms/effect-size/" class="term-link" data-slug="effect-size" title="Cohen's d">Cohen's d</a>. A significance threshold of p 0.05 was applied. Analysis was conducted on an intention-to-treat basis [3].</p>
<h2>Results and Discussion</h2>
<h3>Body Composition Outcomes</h3>
<p>After 12 weeks, both groups demonstrated significant improvements in body composition — reflecting the expected adaptive response to <a href="/terms/progressive-overload/" class="term-link" data-slug="progressive-overload" title="progressive resistance">progressive resistance</a> training. However, the collagen peptide group showed meaningfully greater improvements across all body composition measures [1]:</p>
<table>
<thead>
<tr>
<th>Outcome</th>
<th>Collagen Group</th>
<th>Placebo Group</th>
<th>Between-Group Difference</th>
</tr>
</thead>
<tbody>
<tr>
<td><a href="/terms/lean-body-mass/" class="term-link" data-slug="lean-body-mass" title="Fat-free mass">Fat-free mass</a> change</td>
<td>+4.2 kg</td>
<td>+2.9 kg</td>
<td>+1.3 kg (p 0.05)</td>
</tr>
<tr>
<td>Fat mass change</td>
<td>-5.4 kg</td>
<td>-3.5 kg</td>
<td>-1.9 kg (p 0.05)</td>
</tr>
<tr>
<td>Leg press strength (<a href="/terms/one-repetition-maximum/" class="term-link" data-slug="one-repetition-maximum" title="1RM">1RM</a>)</td>
<td>+58 kg</td>
<td>+45 kg</td>
<td>+13 kg (p 0.05)</td>
</tr>
<tr>
<td>Leg extension strength (1RM)</td>
<td>+28 kg</td>
<td>+21 kg</td>
<td>+7 kg (p 0.05)</td>
</tr>
</tbody>
</table>
<p>These between-group differences are clinically meaningful. A 1.3 kg additional gain in fat-free mass over 12 weeks represents an approximately 45% enhancement of the training effect for the collagen group, a substantial amplification given that both groups performed identical resistance training.</p>
<h3>Mechanism Discussion</h3>
<p>Why would collagen peptide supplementation, which has a notably inferior essential amino acid profile compared to <a href="/terms/whey-protein/" class="term-link" data-slug="whey-protein" title="whey protein">whey protein</a>, enhance skeletal muscle mass gains alongside resistance training in sarcopenic men? Several non-exclusive mechanisms have been proposed:</p>
<p><strong><a href="/terms/connective-tissue/" class="term-link" data-slug="connective-tissue" title="Connective tissue">Connective tissue</a> enhancement</strong>: The most mechanistically supported explanation is that collagen peptide supplementation provided enhanced substrate for synthesis of the muscle connective tissue matrix, particularly the endomysium, perimysium, and myotendinous junction. Improvements in connective tissue integrity may have permitted more effective force transmission, allowing participants to train at higher intensities with less exercise-related discomfort [2].</p>
<p><strong>Reduced exercise-limiting joint pain</strong>: Older adults with sarcopenia commonly have concurrent osteoarthritis and joint degeneration. <a href="/terms/intermittent-fasting/" class="term-link" data-slug="intermittent-fasting" title="If">If</a> collagen supplementation reduced exercise-limiting joint discomfort — as has been reported in separate studies of collagen on joint pain — participants may have achieved greater net training volumes despite similar prescribed protocols, explaining amplified adaptation.</p>
<p><strong>Satellite cell and fibroblast crosstalk</strong>: There is emerging evidence that <a href="/terms/mechanical-tension/" class="term-link" data-slug="mechanical-tension" title="mechanical loading">mechanical loading</a> simultaneously stimulates both myoblast and fibroblast activity in skeletal muscle, and that matrix metalloproteinase activity and extracellular matrix remodeling are integral to hypertrophic adaptation. Collagen precursors may support the connective tissue remodeling that enables net myofibrillar protein accretion [3].</p>
<h3>Limitations and Generalizability</h3>
<p>This study was conducted exclusively in elderly sarcopenic men, limiting direct extrapolation to younger, trained populations or women. The collagen peptide product used (BODYBALANCE) is a proprietary specific peptide formulation — whether effects generalize to generic hydrolyzed collagen requires further study. The absence of a protein-matched control (e.g., whey protein of equivalent caloric/nitrogen content) makes it impossible to determine whether the observed benefits reflect collagen's specific amino acid composition or simply additional dietary protein [4].</p>
<p>The 15g daily dose is substantially higher than typical collagen supplement doses marketed for joint health (typically 5-10g), and the pre-exercise timing was specifically chosen to maximize mechanically stimulated collagen synthesis.</p>
<h2>Practical Applications</h2>
<h3>Who Should Consider Collagen Peptide Supplementation</h3>
<table>
<thead>
<tr>
<th>Population</th>
<th>Rationale</th>
<th>Evidence Strength</th>
</tr>
</thead>
<tbody>
<tr>
<td>Elderly individuals (60+) beginning resistance training</td>
<td>Sarcopenic men showed substantial body composition benefits in this trial</td>
<td>Strong (<a href="/terms/randomized-controlled-trial/" class="term-link" data-slug="randomized-controlled-trial" title="RCT">RCT</a>)</td>
</tr>
<tr>
<td>Athletes with joint pain or <a href="/terms/tendon/" class="term-link" data-slug="tendon" title="tendon">tendon</a> issues</td>
<td>Joint support data from separate studies, complementary to training</td>
<td>Moderate</td>
</tr>
<tr>
<td>Active individuals returning from joint injury/surgery</td>
<td><a href="/terms/connective-tissue/" class="term-link" data-slug="connective-tissue" title="Connective tissue">Connective tissue</a> substrate support during rehabilitation</td>
<td>Moderate</td>
</tr>
<tr>
<td>Healthy young trained athletes for muscle mass</td>
<td>Evidence is weak — low <a href="/terms/essential-amino-acids/" class="term-link" data-slug="essential-amino-acids" title="essential amino acids">essential amino acids</a> limit <a href="/terms/muscle-protein-synthesis/" class="term-link" data-slug="muscle-protein-synthesis" title="muscle protein synthesis">muscle protein synthesis</a> stimulus</td>
<td>Weak</td>
</tr>
</tbody>
</table>
<h3>Dosing Protocol</h3>
<p>The protocol used in this trial provides a clear, evidence-based template:</p>
<ul>
<li><strong>Dose</strong>: 15g collagen peptides per day (higher than typical joint health doses of 5-10g)</li>
<li><strong>Timing</strong>: 30-60 minutes before resistance training (to maximize amino acid availability during mechanically stimulated collagen synthesis)</li>
<li><strong>Form</strong>: Hydrolyzed collagen peptides (not gelatin or intact collagen protein — bioavailability and bioactive peptide content differs)</li>
<li><strong>Vitamin C</strong>: Co-supplementation with 50mg vitamin C is recommended based on vitamin C's cofactor role in collagen synthesis (hydroxylation of proline and lysine residues) [1]</li>
</ul>
<p><strong>On non-<a href="/terms/training-frequency/" class="term-link" data-slug="training-frequency" title="training days">training days</a></strong>: Take at a consistent time with a meal to maintain stable plasma collagen peptide levels.</p>
<h3>Collagen vs. <a href="/terms/whey-protein/" class="term-link" data-slug="whey-protein" title="Whey">Whey</a>: Not an Either/Or Decision</h3>
<p>A critical practical consideration: collagen peptides should not replace whey or other complete protein sources in a training nutrition plan. Collagen's low essential amino acid content and minimal <a href="/terms/leucine/" class="term-link" data-slug="leucine" title="leucine">leucine</a> make it a poor muscle protein synthesis stimulator by itself. The value of collagen supplementation is:</p>
<ul>
<li>Providing specific connective tissue precursors (glycine, proline, hydroxyproline) that leucine-rich proteins deliver in insufficient quantities</li>
<li>Supporting the non-contractile extracellular matrix components of skeletal muscle</li>
<li>Potentially reducing joint pain that limits training capacity and adherence</li>
</ul>
<p>The optimal strategy is to maintain adequate high-quality protein intake (1.6-2.2g/kg/day of leucine-rich complete protein) as the foundation, and add collagen peptides as a targeted supplement for connective tissue support — particularly around exercise [2].</p>
<h3>Practical Cutting Phase Addition</h3>
<p>For individuals in a <a href="/terms/caloric-deficit/" class="term-link" data-slug="caloric-deficit" title="caloric deficit">caloric deficit</a> who are concerned about joint health and lean mass retention:</p>
<ol>
<li><strong>Pre-workout</strong>: 15g collagen peptides + 50mg vitamin C, 30-60 minutes before training</li>
<li><strong>Post-workout</strong>: 25-40g whey or leucine-rich protein source</li>
<li><strong>Throughout the day</strong>: Distribute remaining protein intake across 3-4 additional meals</li>
</ol>
<p>This staggered approach uses collagen for connective tissue priming and whey for maximal muscle protein synthesis signaling.</p>
<h3>Realistic Expectations</h3>
<ul>
<li>Collagen peptide supplementation is not a substitute for adequate total protein or resistance training</li>
<li>In sarcopenic older adults, the evidence supports meaningful body composition improvements when combined with resistance training</li>
<li>In healthy younger populations with adequate protein intake, the incremental benefit for <a href="/terms/muscle-hypertrophy/" class="term-link" data-slug="muscle-hypertrophy" title="muscle hypertrophy">muscle hypertrophy</a> specifically is likely small — but connective tissue support and joint health benefits may still be relevant</li>
<li>Joint pain reduction effects, while reported separately in multiple trials, are typically modest and require 2-3 months of consistent supplementation to manifest [3]</li>
</ul>