An observational study in Overweight and Obese Adults, sponsored by University of Birmingham. Recruiting at 1 site in United Kingdom. Open to participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-19.
Sponsored by University of Birmingham · Observational
It is well known that individuals living with overweight or obesity are not able to activate skeletal muscle growth processes to the same extent as lean individuals following activities such as weightlifting (resistance exercise) or protein ingestion. However, the underlying cell signalling pathways which may be regulating these impairments are not fully understood. This study aims to understand if skeletal muscle signalling responses to resistance exercise and protein intake differ between lean individuals and those living with overweight or obesity. The investigators will recruit a cohort of lean individuals and a cohort of individuals living with overweight/obesity who will undertake a bout of single-leg resistance exercise and consume a protein-rich drink. Before and after this, muscle samples will be obtained from each leg of participants at different timepoints to understand the effects of exercise and feeding combined (exercised leg) and feeding alone (rested leg) on different cellular processes which regulate muscle growth. This will allow the investigators to understand if their are specific pathways within skeletal muscle which could be targeted in future interventions to overcome impaired protein metabolism in those living with overweight/obesity.
As skeletal muscle is a major contributor to basal metabolic rate and glucose control, increasing the quality of skeletal muscle in those living with obesity could improve the long-term success of subsequent weight loss programs. There are two main activities which are often recommended to improve skeletal muscle quality, resistance exercise (i.e. weightlifting) and adequate protein intake, however, recent research has suggested that individuals living with obesity do not respond as well to these activities as a non-obese person. This research project aims to investigate if certain processes within muscle cells, which regulate muscle size and quality, are reduced in people living with obesity following a single session of resistance exercise and a protein-rich drink. This will hopefully identify processes we can target specifically to improve skeletal muscle quality. The project involves participants attending the lab and completing a session of single-leg resistance exercise and ingesting a protein drink. Before and after this the investigators will take a number of blood samples and small pieces of muscle from each thigh to understand how muscle reacts to exercise/feeding and whether this differs between individuals with and without obesity. Following the visit investigators will the conduct a variety of laboratory analysis on these samples to understand the responses. Overall, this project has the potential to help design future programmes which can improve skeletal muscle quality in those living with obesity, improving general health and increasing success of weight loss interventions.
To date, the acute effects anabolic stimulation by resistance exercise and protein ingestion in individuals with obesity have been shown to be blunted. However, the mechanisms responsible for this have scarcely been investigated. We intend to build on current evidence by identifying what causes this blunted response to anabolic stimulation in individuals with obesity.
This project aims to determine whether individuals with obesity exhibit differential mTORC1-lysosomal translocation in response to anabolic signaling following a single bout of resistance exercise combined with protein ingestion.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's planned enrollment of 24 is below the median of 114 across 2,154 observational studies indexed under Obesity.
Browse Obesity studies →University of Birmingham is the lead sponsor of 182 studies on the registry; 29 are open to participants now.
Compared within Obesity, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Overweight. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Participants will be recruited from around the West Midlands area via recruitment media.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
This cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of 18.5-25.9kg/m2. They will also have been weight-stable (\<5% bodyweight change in previous 6 months).
Procedure: Skeletal muscle biopsy · Procedure: venous blood sampling · Dietary Supplement: Protein-Rich Beverage · Other: Single-leg resistance exercise · Radiation: Dual-Energy X-ray Absorptiometry (DEXA) Scan · Other: Maximal Strength Testing
This cohort will be aged between 18-45yrs and have a Body Mass index (BMI) of \>28kg/m2. They will also have been weight-stable (\<5% bodyweight change in previous 6 months).
Procedure: Skeletal muscle biopsy · Procedure: venous blood sampling · Dietary Supplement: Protein-Rich Beverage · Other: Single-leg resistance exercise · Radiation: Dual-Energy X-ray Absorptiometry (DEXA) Scan · Other: Maximal Strength Testing
On five occasions throughout the experimental visit, skeletal muscle biopsies will be obtained from the vastus lateralis of participants (3 in rested leg, 2 in exercised leg). These will be completed under local anaesthetic using the Bergstrom needle technique, modified for suction.
Upon arrival at the experimental visit, participant will have a cannula inserted into their antecubital vein for repeated blood sampling. 12 blood samples will then be taken throughout the course of the experimental trial from which both plasma and serum will be isolated.
Following completion of the acute, single-leg resistance exercise bout, participants will consumed a protein-rich beverage containing 0.25g/kg bodyweight whey protein (dissolved in 300ml water).
During the experimental visit, participants will complete an acute bout of single-leg knee extensions on a randomised leg. This will be comprised of 6 sets of knee extensions at 80% of participants pre-determined 1 repetition maximum (1RM), with each set completed to volitional failure separated by a 2 minute rest interval.
During Visit 1 of the study, participants will undergo a whole-body DEXA scan to assess body composition (body fat and fate-free mass). This short, painless scan exposes participants to a small amount of radiation which is equivalent to the amount exposed to during a transatlantic flight.
During Visit 1 of the study, participants will undergo maximal knee extension strength testing using a randomised leg (which will complete exercise during experimental trial). This will involve increasing the weight on the knee extension machine until the participant can no longer complete a single repetition. This weight will then be used to calculate the workload at which the participant will complete the exercise bout during the experimental trial.
Also known as: 1RM testing
mTORC1-lysosomal translocation
The translocation of the mTORC1-lysosomal complex toward the cell periphery following resistance exercise and/or protein ingestion will be assessed in skeletal muscle cross sections via immunofluorescence microscopy.
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
mTORC1 activation
Markers of mTORC1 activation (phosphorylation of downstream signalling targets) will be assessed via immunoblotting on homogenised skeletal muscle samples.
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Autophagic Flux
Skeletal muscle autophagic flux will be assessed on skeletal muscle samples using a novel ex vivo assay followed by immunoblotting.
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Lysosomal Content
Skeletal muscle lysosomal content will be assessed via immunoblotting for markers of the lysosome on homogenised skeletal muscle samples
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Circulating Amino Acids Concentrations
Amino acid concentrations will be assessed via high performance liquid chromatography to determine how much of the protein ingested arrives in circulation
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Circulating Hormone Concentrations
Hormones associated with glycaemic control (glucose \& insulin) will be assessed in plasma/serum samples via colorometric assay or ELISA
Time frame: From completion of experimental testing/biosample collection until end of study, an average of 1 year.
Plan to share: Yes — IPD used in publications arising from the project will be shared upon request
Supporting information: Study protocol
Time frame: IPD will be available upon request following publication of the IPD with no end date
Access criteria: Qualified researchers with an approved scientifically sound research proposal from recognized academic, clinical, or commercial institutions can request IPD from the principal investigator. In such cases, the de-identified data long with the study protocol will be provided via a secure cloud-based research environment.
No publications or documents are linked to this record.
Started Apr 2026 (actual). Primary completion is estimated for Dec 2026, 8 months after the start.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.