The Effect of Vitamin C-enriched Collagen Combined With Resistance Training on Muscle-tendon Unit Properties in Middle-aged Men and Women
Phase: NA
Conditions: Diet, Food, Nutrition
Sponsor: Liverpool John Moores University

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The Effect of Vitamin C-enriched Collagen Combined with Resistance Training on Muscle-
tendon Unit Properties in Middle-aged Men and Women 
 
Study protocol, statistical analysis plan and informed consent form. 
Document date: 04/22/2024 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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1. Participant Flow 
 
 
 
 
Figure 1. Flowchart of participant recruitment and intervention timeline (males). 
 
 
 
 
 

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Figure 2. Flowchart of participant recruitment and intervention timeline (females). 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Study Protocol 
Brief Summary:  
The aim of this clinical trial is to investigate the longitudinal effects of hydrolyzed collagen ingestion 
combined with resistance training on muscle-tendon unit structure and function in middle-aged males 
and females. 
 
The main research questions this clinical trial aims to answer are: 
 
1. Does resistance training with hydrolyzed collagen ingestion lead to greater changes in tendon 
properties than resistance training alone in middle-aged health men and women? 
 
2. Does resistance training with hydrolyzed collagen ingestion lead to greater changes in muscle 
size than resistance training alone? 
 
 
3. Does resistance training with hydrolyzed collagen lead to greater increases in strength and 
power compared to resistance training alone in middle-aged, healthy men and women? 
Participants will be randomly assigned to collagen or placebo groups. Participants will perform 24 
sessions of high intensity resistance training across 12-weeks. Alongside each training session, 
participants will consume a beverage containing hydrolyzed collagen or maltodextrin, with both 
beverages containing vitamin C. 
Researchers will compare the collagen and placebo groups to see if there would be beneficial effects 
on changes in muscle and tendon that are greater than resistance training alone. To achieve this, an 
dynamometry will be used to assess lower limb strength and ultrasound will be used to measure the 
morphological, mechanical, and material properties of the patellar tendon, as well the size and 
architecture of the vastus lateralis muscle. 
 
Detailed Description: 
 
Healthy, active, middle-aged men and women will ingest a beverage containing 30 g of hydrolyzed 
collagen with 50 mg of vitamin C or a calorie matched beverage (maltodextrin), also with 50 mg of 
vitamin C combined with high-volume, high-intensity resistance training for the lower body on 2 - 3 
occasions per week for 8-12 weeks. 
 
The aim of this study was to investigate the effect of combining hydrolyzed collagen with resistance 
training in middle-aged men and women.If supplementation with hydrolyzed collagen leads to a 
greater change in tendon size, stiffness, and Young's modulus than resistance training alone, this will 
allow us to recommend this type of intervention to young athletes seeking to improve tendon health 
and/or athletic performance. This is the first study to investigate the combination of hydrolyzed 
collage supplementation with resistance training in middle-aged men and women. If supplementation 
with hydrolyzed leads to greater improvements in tendon size, stiffness, strength and/or power, this 

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will allow us to recommend this type of intervention to middle-aged athletes/trainees seeking to 
improve tendon health, reduce injury risk, or enhance athletic performance. 
The experimental design of both arms will be the same, however Arm 1 will be health, middle-aged 
male participants and Arm 2 will be health, middle-aged female participants. 
 
Arm/Group Information 
Arm 1: 
Training and nutrition intervention for middle-aged male participants (aged 35 - 59 years) who 
consumed hydrolyzed collagen (HC) or a placebo beverage with progressive resistance training. 
Arm 1 Description: 
This arm was designed as a double-blind, randomized control study with parallel groups. Middle-aged, 
recreationally trained men, pair-matched by age, body mass, height and baseline strength, were 
randomly allocated to the collagen (COL) or placebo (PLA) group. 
During their initial laboratory visit, participants were screened and provided with a 3-day food diary 
and its completion instructions. Before undergoing baseline assessments, participants engaged in a 
warm-up routine that included 5 minutes of low-intensity jogging followed by 5 minutes of dynamic 
stretching. The baseline assessments of lower limb muscle-tendon unit properties, lower limb strength 
and power were conducted at the same time of day to mitigate any potential circadian effects. 
The 12-week progressive lower-limb resistance training program comprised a combination of 
supervised and home-based training sessions focused on overloading the quadriceps femoris muscle-
tendon unit. Training loads were adjusted weekly based on the prior session's performance using a 
linear progression model. 
Each session was accompanied by the consumption of a flavor matched beverage. This beverage 
contained either 0 or 30 grams of hydrolyzed collagen (HC), combined with vitamin C. The 0 g beverage 
also contained vitamin C and was matched with the 30 g beverage for caloric content by the inclusion 
of maltodextrin. 

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Post-intervention, participants returned to the laboratory 72 hours after their final training session to 
repeat all baseline assessments. 
Arm 2: 
Training and nutrition intervention for middle-aged female participants (aged 35 - 59 years), who 
consumed hydrolyzed collagen (HC) or a placebo beverage with progressive resistance training. 
Arm 2 Description: 
This arm was identical to Arm 1 (male cohort), however it was conducted in middle-aged females. 
1. Period 
Arm 1: Participants were recruited from university staff, and sports and leisure clubs. Recruitment 
began in June 2021 and data collection was completed in December 2021. 
Arm 2: Participants were recruited from university staff and sports clubs. Recruitment began in March 
2023 and data collection was completed in June 2023. 
2. Baseline Characteristics 
Arm 1: 20 middle-aged males (mean ± SD; age, 47 ± 5 years, body mass, 81 ± 12 kg; height 178 ± 7 cm) 
Arm 2: 22 middle-aged females (mean ± SD; age 37 ± 2 years, body mass, 69 ± 8 kg, 168 ± 4 cm) 
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Age 
o > 35 and < 59 years; 
• 
Sex 
o Male and female 
• 
Ethnicity 
o Race and ethnicity information not collected 
• 
Region of enrolment 
o Arm 1: Carlow, Ireland 
o Arm 2: Dublin, Ireland 
 

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3. Outcome measure information 
Table 1. Outcome measures by study arm 
  
Number of participants analyzed 
Description 
Time frame 
Primary 
42 (Arm1: 20; Arm 2: 22) 
m. vastus lateralis thickness (in millimeters)  
Data analyzed between January 
2022 & September 2023 
Primary 
43 (Arm1: 20; Arm 2: 22) 
m. vastus lateralis fascicle pennation  angle (in degrees)  
Data analyzed between January 
2022 & September 2023 
Primary 
43 (Arm1: 20; Arm 2: 22) 
Patellar tendon cross sectional area (in squared 
millimeters) at 3 regions along the tendon length 
Data analyzed between January 
2022 & September 2023 
Primary 
43 (Arm1: 20; Arm 2: 22) 
Bilateral vertical countermovement jump height (in 
centimeters) 
Data analyzed between January 
2022 & September 2023 
Primary 
Arm 1: 20 
Patellar tendon stiffness (in Newtons per millimeter) 
Data analyzed between January 
2022 & September 2023 

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Primary 
Arm 1: 20 
Knee extensor maximal isometric torque (in Newton 
meters)   
Data analyzed between January 
2022 & September 2023 
Primary 
Arm 1: 20 
Knee extensor rate of torque development (in Newton 
meters per second) 
Data analyzed between January 
2022 & September 2023 
Primary 
Arm 1: 20 
Barbell back squat 10-repetition maximum (in 
kilograms) 
Data analyzed between January 
2022 & September 2023 
Primary 
Arm 1: 20 
Bilateral horizontal broad jump distance (in 
centimeters) 
Data analyzed between January 
2022 & September 2023 
Primary 
Arm 2: 22 
Lower limb maximal isometric force (in Newtons) 
Data analyzed between July 
2023 & September 2023 
Primary 
Arm 2: 22 
Lower limb isometric rate of force development (in 
Newtons per second) 
Data analyzed between July 
2023 & September 2023 
Primary 
Arm 2: 22 
20-metre sprint time (in seconds) 
Data analyzed between July 
2023 & September 2023 
 

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Statistical Analyses Plan (SAP) 
In Arm 1, data from 20 male participants were analyzed and in Arm 2, data from 22 female 
participants were analyzed. The analyses of data collected from each arm were performed 
independently. All variables were ratio data, and normal distribution was assessed using the Shapiro-
Wilk test, along with visual inspections of histograms, Q-Q plots, and box plots. All data met the 
assumptions of the parametric statistical analyses used in the study. Independent t-tests were used 
to assess differences between groups (COL, collagen and PLA, placebo) at baseline for all measures. 
The two-way analysis of variance (ANOVA) was performed on all measures taken at baseline and after 
the intervention to assess the main effects of group (COL vs PLA), time (pre- vs post- intervention), 
and any group × time interactions. The only exceptions to this were for patellar tendon cross-sectional 
area, and rate of torque/force development. For the patellar tendon cross-sectional, a three-way 
ANOVA was used to assess main effect of location (along the length of the tendon), and any 
interactions between location, time (pre- to post- intervention) and group (COL vs PLA). Likewise for 
rate of torque/force development, a three-way ANOVA was used to assess main effect of time-window 
(0 – 50, 50 – 100, 100 – 150 ms after the onset of torque/force), time (pre- to post- intervention) and 
group (COL vs PLA) and any interactions between time-window, time and group. When significant 
main effects or interaction effects were observed, paired t-tests were used for post hoc pairwise 
comparisons. The level of statistical significance was set at P < 0.05 
4. Adverse Event Information  
During data collection period, any adverse event such as all-cause mortality or serious adverse 
event did not occur. 
5. Certain Agreements  
Are all PIs Employees of Sponsor? Yes 
Results Disclosure Restriction on PI(s)? 
No 

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6. Results Point of Contact  
Dr Rob Erskine Research Institute for Sport and Exercise Sciences, Liverpool John Moores 
University Tel: +44 (0)151 904 62; E-mail: R.M.Erskine@ljmu.ac.uk 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

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Informed Consent Form 
Please note that this contains legacy information, as the institution granting ethical approval (Institute 
of Technology, Carlow) is now known as South East Technological University. Ethical approval for this 
study was granted on 03/24/2021. 
 
CONSENT TO PARTICIPATE IN RESEARCH 
The Effect of Vitamin C-enriched Collagen Combined with Resistance Training on Muscle-tendon 
Unit Properties in Middle-aged Men and Women 
 
You are being invited to participate in a research study about the adaptations that occur in our body 
after 10 weeks of resistance exercise combined with Vitamin C-enriched Collagen supplementation. 
We will be observing the effect of a progressive resistance intervention combined with vitamin c 
enriched collagen supplementation on changes in lower limb strength measured by dynamometry, as 
well as muscle and tendon properties measured using ultrasound. This study is being conducted by 
Christopher Nulty, Lecturer from the Department of Health and Sport Sciences at Institute of 
Technology Carlow (herein referred to as IT Carlow).  Kieran Phelan, Masters by research student in 
the department, will assist in conducting this study as part of a MSc dissertation.  
Your participation in this study is entirely voluntary. Please read the information below and ask 
questions about anything you do not understand, before deciding whether to participate. 
You have been asked to participate in this study because this research is specifically looking at the 
effects of collagen supplementation with resistance training in middle-aged adults. You have met the 
criteria outlined in the participant information sheet and expressed interest. 
 
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PURPOSE OF THE STUDY 
The purpose of this study is to investigate the changes that occur in the middle-aged muscle and 
tendon when supplementing with vitamin C-enriched collagen throughout a progressive resistance 
exercise program.  
 
 
 

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PROCEDURES 
 
If you volunteer to participate in this study, you will be asked to be available and perform the 
following: 
Familiarization & Baseline 
testing 
 
 
Training 
Intervention 
 
 
Post-training 
follow-up 
 
  
  
 
 
  
  
Visit 
1 
~ 
45 
mins, 
familiarization 
with 
measurements below 
Visit 2 ~90 mins, Baseline 
assessment 
of 
measures 
below 
 
 
 
  
24 training sessions, ~ 30 
mins per session 
 
2 times 
per week 
 
 
Final visit  ~ 90 mins 
 
Repeat all measures from 
visit 2 
Anthropometric 
measurements 
Muscle size 
Tendon size and stiffness 
Lower limb strength test 
 
 
 
12-week 
Resistance  
Training focused on lower 
body compound exercises 
 
 
 
 
Figure 1. An overview of the study intervention periods and measurements. For further information 
please consult the participant information sheet 
 
 
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POTENTIAL RISKS AND DISCOMFORTS 
 
You will learn the correct technique for each exercise during the familiarization session. A standard 
warm-up, sufficient rest periods and controlled range of motion will be provided. The exercises will 
be immediately ceased if participants feel uncomfortable. You are likely to experience mild discomfort 

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and stiffness known delayed onset muscle soreness (DOMS) in 24 – 72 hours after the first training 
session. This is a normal response to resistance exercise and should lessen over time.  
In the event of physical and/ or mental injury resulting from participation in this research project, IT 
Carlow does not provide any medical, hospitalization or other insurance for participants in this 
research study, nor will IT Carlow provide any medical treatment or compensation for any injury 
sustained as a result of participation in this research study, except required by law. 
 
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POTENTIAL BENEFITS TO SUBJECTS AND/ OR TO SOCIETY 
 
This study will provide you the opportunity to partake in a supervised exercise program designed by 
sport scientists. It is expected that your strength and muscle size will be increased, and your tendon 
health improved regardless of whether you are in the collagen group or not. As the training will be 
performed in groups, there may be benefits to mental health, stress and anxiety and you may make 
social connections with people of similar interests. The findings of this study will be made available 
through scientific communication, and will be of benefit to middle-aged trainees seeking to improve 
tendon health, reduce injury risk, and or enhance exercise performance 
 
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CONFIDENTIALITY 
 
Any information that is obtained in connection with this study and that can be identified with you will 
remain confidential and will be disclosed only with your permission or as required by law. Each 
participant will be allocated a personal ID. The only place the participants name and code will be 
together will be on the Informed Consent and an electronic spreadsheet (Excel). This spreadsheet will 
be stored in the IT Carlow G-drive storage facility with password-controlled access. All data will be 
deleted from other storage devices once transferred to a password-controlled IT Carlow computer. 
The researcher will deliver and collect the questionnaires and consent form on a one-to-one basis. 
Any data for the consent forms be only shared with my supervisors. The only identifiable information 
will be the consent form, which will be kept in a locked filing cabinet within the IT Carlow Research 
Office and an electronic (Excel) spreadsheet stored only in the IT Carlow G-drive storage facility with 
password-controlled access.. Confidentiality may be broken if there is a strong belief that there is a 
serious risk of harm or danger to either the participant or another individual (e.g. physical, emotional 
or sexual abuse, concerns for child protection, rape, self-harm, suicidal intent or criminal activity) or if 
a serious crime has been committed. 
 
The Institute of Technology Carlow is committed to protecting the rights and privacy of individuals 
with respect to the processing of their personal data. A copy of the Institute’s Privacy notice is 
available on the Institute’s website (https://www.itcarlow.ie/resources/data-protection.htm ). This 
website also contains further information relating to your rights regarding subject access requests, 
records retention and data protection in general. Any further queries in relation to the GDPR can be 
addressed to the Institute’s Data Protection Oversight Group (e-mail: gdpr@itcarlow.ie)  
 

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• 
PARTICIPATION AND WITHDRAWAL 
 
Participation is entirely voluntary. If you volunteer to be in this study, you can withdraw at any time 
by informing the investigators without giving a reason and without it affecting your rights/any future 
treatment/service you receive. 
The investigator(s) may withdraw you from this research if circumstances arise which warrant doing 
so. This situation may arise if there is a strong belief that there is a serious risk of harm or danger to 
either the participant or another individual (e.g. physical, emotional or sexual abuse, concerns for child 
protection, rape, self-harm, suicidal intent or criminal activity) or if a serious crime has been 
committed. Additionally, you may be withdrawn if you do not adhere to the study protocol. If you do 
decide to take part, you will be asked to sign this consent form. 
 
• COMPENSATION FOR PARTICIPATION  
You will not receive any payment or other compensation for participation in this study. There is also 
no cost to you for participation. 
 
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IDENTIFICATION OF INVESTIGATORS 
If you have any questions about the study, please do not hesitate to contact: 
Christopher Nulty  
Lecturer, Dept. of Science & Health 
South East Technological University  
Christopher.nulty@setu.ie; c.nulty@2019.ljmu.ac.uk 
 
Dr. Robert M. Erskine 
Research Institute for Sport and Exercise Sciences,  
Liverpool John Moores University 
Tel: +44 (0)151 904 62; E-mail: R.M.Erskine@ljmu.ac.uk 
 
Kieran Phelan 
Researcher 
Dept. of Science & Health 
Institute of Technology Carlow 
Kieran.phelan@itcarlow.ie 

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•  RIGHTS OF RESEARCH PARTICIPANTS 
IT Carlow’s Research Ethics Committee has reviewed and approved our request to conduct this project 
(Approval no. 300).  If you have any concerns about your rights in this study, please contact the Chair 
of the Research Ethics Committee, Dr. Brian Jackson (Brian.Jackson@setu.ie)  
I understand the procedures described above. My questions have been answered to my satisfaction, 
and I agree to participate in this study. I have been given a copy of this form. 
 
________________________________________ 
 
 _________________________ 
Printed Name of Participant 
 
 
 
 
 
Date 
________________________________________ 
 
_________________________ 
Signature of Participant 
 
 
 
 
 
Date 
________________________________________ 
 
_________________________ 
Signature of Researcher 
 
 
 
 
 
Date