Skeletal Muscle

The goal of this study is to learn how different amounts of supervised indoor cycling training change gut health (gut bacteria, the substances gut bacteria make, and the gut barrier integrity), and how these changes relate to changes in fitness, muscle health, and signs of doing too much training (a state called 'overreaching'). The study includes healthy, recreationally active men aged 18 to 45 years. The primary questions, for which the study is powered (sufficient participants included), are: 1. Does moderate load training change blood and faecal levels of butyrate (a short-chain fatty acid made by gut bacteria) after eight weeks compared with a control group? 2. Compared to moderate load training, do higher training loads lead to different responses in blood and faecal levels of butyrate? Researchers will compare: * A control group that does not complete structured training; * A moderate-load training group that completes eight weeks of supervised cycling (4x/week); * A high-load training group that completes four weeks of moderate-load training followed by four weeks of higher training load (twice the number of training sessions). Participants will: * Be randomly assigned to one of the three groups; * Complete 8 weeks of supervised indoor cycling sessions if assigned to a training group; * Complete four study assessment periods (baseline, after week four, after week eight, and after a short taper (rest period); * Provide blood, stool, skeletal muscle, urine, saliva, and breath samples during the assessment periods; * Complete fitness and performance tests and questionnaires during the assessment periods.

The use of glucagon-like peptide receptor agonists (GLP-1 RAs) may have clinically important effects on skeletal muscle mass (SMM), and physical function. The effects of exercise training in conjunction with GLP-1 RA therapy on these outcomes has not been studied. Additionally, most people treated with GLP-1-based weight loss medications stop taking these medications within 1 year of initiating treatment. This is an important clinical concern because weight regain can occur after weight loss pharmacotherapy is stopped and the impact of stopping GLP-1 RA therapy on physical and metabolic function has not been studied. In this study, the investigators will conduct a 2-year randomized clinical trial to evaluate body composition, muscle physical and metabolic function, and muscle strength in response to GLP-1 RA therapy, with or without exercise training, and subsequent treatment cessation on muscle-related outcomes.

The purpose of this study is to evaluate the acute local skeletal muscle inflammatory response to thigh muscle (quadriceps) eccentric muscle actions. Eccentric muscle actions occur when the muscle is lengthening as it contracts. This is a pilot project to assess the degree of inflammatory biomarkers, called myokines, that are released locally in skeletal muscle tissue after an acute bout of resistance-exercise using a resistance-exercise machine called an isokinetic dynamometer.

This project adopts a prospective study design. It is scheduled to enroll 60 participants diagnosed with Head and Neck cancer in this hospital, of which 30 are in the experimental group and 30 are in the control group. The purpose of this research is to analyze the skeletal muscle mass changes on images in Head and Neck cancer patients after exercise training and the association with systemic inflammatory markers. Investigators would like to know whether these images and biomarkers predict the prognosis of Head and Neck cancer. Subjects enrolled in the trial will receive 36 times of exercise training after concurrent chemoradiotherapy. Before and after the completion of exercise training, investigators will arrange (1) dual energy X-ray absorptiometry (DXA) to measure the whole-body skeletal muscle mass and appendicular skeletal muscle mass and (2) blood tests for markers of systemic inflammation. In addition to DXA, computed tomography (CT) is another image modality for skeletal muscle mass evaluation. Positron emission tomography - CT or whole-body CT for cancer staging are considered as baseline studies. The routine follow-up CT images are used to analyze the changes after exercise training. If magnetic resonance imaging is also performed during the follow-up period, images will also be collected and assessed as an alternative.If the experimental group can maintain or even improve skeletal muscle mass and can be reflected in blood tests and prognosis, the result may be able to apply on cancer treatment and disease followup.

The purpose of this study is to evaluate if acute ingestion of L-arginine will enhance anaerobic exercise performance in young, healthy, and recreationally active adults.