Changes in Muscle Mass and Strength During Follow-Up After One-Year Resistance Training Interventions in Older Adults.

Mertz, KH, Reitelseder, S, Rasmussen, MA, Bülow, J, Højfeldt, G, Jensen, M, Hjulmand, M, Lindberg, J, Kramer, MU, Bechshøft, R, and Holm, L. Changes in muscle mass and strength during follow-up after one-year resistance training interventions in older adults. J Strength Cond Res 37(10): 2064-2070, 2023-The aim of this study was to investigate if home-based resistance training compared with center-based resistance training was associated with better preservation of muscle mass and strength in older individuals, 6 months after the interventions ended.

Effect of 1-year daily protein supplementation and physical exercise on muscle protein synthesis rate and muscle metabolome in healthy older Danes: a randomized controlled trial.

Background: The skeletal muscle mass decreases with age and the responsiveness of aging muscles' protein synthesis rate (MPS) to protein intake seems to deteriorate.

Objective: This study investigated the impact of 12 months of protein supplementation with or without physical exercise training on the basal and postprandial MPS and the skeletal muscle metabolome of healthy older Danes (> 65 years, 29 females/37 males).

Methods: Subjects were randomized to follow one of five intervention groups: (1) carbohydrate, (2) collagen protein, (3) whey protein, (4) home-based light resistance training with whey protein, and (5) center-based heavy-load resistance training with whey protein.

Co-ingestion of cluster dextrin carbohydrate does not increase exogenous protein-derived amino acid release or myofibrillar protein synthesis following a whole-body resistance exercise in moderately trained younger males: a double-blinded randomized controlled crossover trial.

Purpose: This study investigates if co-ingestion of cluster dextrin (CDX) augments the appearance of intrinsically labeled meat protein hydrolysate-derived amino acid (D-phenylalanine), Akt/mTORC1 signaling, and myofibrillar protein fractional synthetic rate (FSR).

Methods: Ten moderately trained healthy males (age: 21.5 ± 2.

Human Fecal Metabolome Reflects Differences in Body Mass Index, Physical Fitness, and Blood Lipoproteins in Healthy Older Adults.

This study investigated how body mass index (BMI), physical fitness, and blood plasma lipoprotein levels are related to the fecal metabolome in older adults. The fecal metabolome data were acquired using proton nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry on 163 healthy older adults (65-80 years old, 80 females and 83 males). Overweight and obese subjects (BMI ≥ 27) showed higher levels of fecal amino acids (AAs) (valine, alanine, and phenylalanine) compared to normal-weight subjects (BMI ≤ 23.

Postprandial muscle protein synthesis rate is unaffected by 20-day habituation to a high protein intake: a randomized controlled, crossover trial.

Purpose: During the last decade more researchers have argued in favor of an increased protein intake for older adults. However, there is a lack of knowledge on the long-term effects of conforming to such a high protein intake with regards to the basal and postprandial muscle protein turnover. The purpose of this study was to compare the postprandial synthesis response in muscle proteins, and the abundance of directly incorporated food-derived amino acids following habituation to high vs.

The effect of daily protein supplementation, with or without resistance training for 1 year, on muscle size, strength, and function in healthy older adults: A randomized controlled trial.

Background: Protein supplementation alone or combined with resistance training has been proposed to be effective in counteracting age-related losses of muscle mass and strength.

Objectives: To investigate the effect of protein supplementation alone or combined with light-intensity or heavy-load resistance exercise on muscle size, strength, and function in older adults.

Methods: In a 1-y randomized controlled trial, 208 healthy older adults (>65 y) were randomly assigned to 1 of 5 interventions: 1) carbohydrate supplementation (CARB); 2) collagen protein supplementation (COLL); 3) whey protein supplementation (WHEY); 4) light-intensity resistance training 3-5 times/wk with whey protein supplementation (LITW); and 5) heavy resistance training 3 times weekly with whey protein supplementation (HRTW).

Divergent Anabolic Response to Exercise in Young and Older Adult Men-Dependency on Time Frame of Measurement.

Older adults' skeletal muscle has shown to be less responsive to anabolic stimuli as compared to young both in vitro, in short and controlled in vivo settings and in long-term training studies. However, to translate controlled mechanistic findings to long-term adaptations intermediate measures allowing daily life routines with regard to activity and diet would be useful to evaluate physiological interventions. The purpose of this study was to investigate the exercise effect in young and older adults with 2 independent methods to measure muscle protein synthesis rate.

Impact of habituated dietary protein intake on fasting and postprandial whole-body protein turnover and splanchnic amino acid metabolism in elderly men: a randomized, controlled, crossover trial.

Background: Efficacy of protein absorption and subsequent amino acid utilization may be reduced in the elderly. Higher protein intakes have been suggested to counteract this.

Objectives: We aimed to elucidate how habituated amounts of protein intake affect the fasted state of, and the stimulatory effect of a protein-rich meal on, protein absorption, whole-body protein turnover, and splanchnic amino acid metabolism.

Effects of Prolonged Whey Protein Supplementation and Resistance Training on Biomarkers of Vitamin B12 Status: A 1-Year Randomized Intervention in Healthy Older Adults (the CALM Study).

We investigated the effect of long-term whey supplementation on biomarkers of B12 status in healthy older adults subjected to different schemes of supplements and exercise. The total study population examined at baseline consisted of 167 healthy older adults (age ≥ 65 year) who were randomized to 1-y intervention with two daily supplements of (1) whey protein (3.1 µg B12/day) (WHEY-ALL), (2) collagen (1.

Physical fitness in community-dwelling older adults is linked to dietary intake, gut microbiota, and metabolomic signatures.

When humans age, changes in body composition arise along with lifestyle-associated disorders influencing fitness and physical decline. Here we provide a comprehensive view of dietary intake, physical activity, gut microbiota (GM), and host metabolome in relation to physical fitness of 207 community-dwelling subjects aged +65 years. Stratification on anthropometric/body composition/physical performance measurements (ABPm) variables identified two phenotypes (high/low-fitness) clearly linked to dietary intake, physical activity, GM, and host metabolome patterns.

Development of a Mobility Diet Score (MDS) and Associations With Bone Mineral Density and Muscle Function in Older Adults.

Reduced bone mineral density (BMD) and muscle function is associated with increased risk of multiple health related issues. Diet may play a role in sustaining BMD and muscle function throughout old age, but much is still to be learned with regards to which specific food groups and dietary patterns that are important for such outcomes. The aim of the current study was to identify food groups important for both BMD and muscle function.

Contrast-enhanced ultrasound using bolus injections of contrast agent for assessment of postprandial microvascular blood volume in human skeletal muscle.

Methods capable of measuring blood flow in a tissue-specific manner are needed. The purpose of this study was to investigate whether contrast-enhanced ultrasound (CEUS) using bolus injections of SonoVue is an useful method for assessing postprandial changes in microvascular perfusion in the vastus lateralis muscle. Ten healthy, young subjects were recruited for this study.

Effect of Losartan on the Acute Response of Human Elderly Skeletal Muscle to Exercise.

Purpose: To investigate the effect of blocking the angiotensin II Type I receptor (AT1R) upon the response to acute heavy-resistance exercise in elderly human skeletal muscle. The hypothesis was that AT1R blocking would result in a superior myogenic response accompanied by down-regulation of transforming growth factor-beta and up-regulation of insulin-like growth factor-1 signaling.

Methods: Twenty-eight healthy elderly men (+64 yr) were randomized into two groups, consuming either AT1R blocker (losartan, 100 mg·d) or placebo for 18 d before exercise.

Effect of light-load resistance exercise on postprandial amino acid transporter expression in elderly men.

An impaired amino acid sensing is associated with age-related loss of skeletal muscle mass. We tested whether light-load resistance exercise (LL-RE) affects postprandial amino acid transporter (AAT) expression in aging skeletal muscle. Untrained, healthy men (age: +65 years) were subjected to 13 h of supine rest.

Light-load resistance exercise increases muscle protein synthesis and hypertrophy signaling in elderly men.

The present study investigated whether well-tolerated light-load resistance exercise (LL-RE) affects skeletal muscle fractional synthetic rate (FSR) and anabolic intracellular signaling as a way to counteract age-related loss of muscle mass. Untrained healthy elderly (>65-yr-old) men were subjected to 13 h of supine rest. After 2.

No additional effect of different types of physical activity on 10-hour muscle protein synthesis in elderly men on a controlled energy- and protein-sufficient diet.

Purpose: The elderly lose skeletal muscle mass with age, which may be detrimental for function and quality of life. Both inactivity and heavy resistance exercise are known to have marked but opposite effects upon muscle mass. However, the potential effects of daily physical activity upon muscle protein synthesis (MPS) are less investigated.

The single-biopsy approach in determining protein synthesis in human slow-turning-over tissue: use of flood-primed, continuous infusion of amino acid tracers.

Muscle protein synthesis (MPS) rate is determined conventionally by obtaining two or more tissue biopsies during a primed, continuous infusion of a stable isotopically labeled amino acid. The purpose of the present study was to test whether tracer priming given as a flooding dose, thereby securing an instantaneous labeling of the tissue pools of free tracee amino acids, followed by a continuous infusion of the same tracer to maintain tracer isotopic steady state, could be used to determine the MPS rate over a prolonged period of time by obtaining only a single tissue biopsy. We showed that the tracer from the flood prime appeared immediately in the muscle free pool of amino acids and that this abundance could be kept constant by a subsequent continuous infusion of the tracer.