Equivalent servings of free-range reindeer promote greater net protein balance compared to commercial beef.

Wild game consumption has been associated with health benefits but the acute influence on human protein metabolism remains unknown. We compared feeding-induced responses of equivalent amounts of free-range reindeer (FR) and commercial beef (CB) on protein kinetics using stable isotope methodology. Seven participants (age: 40 ± 14 years; body mass index: 24 ± 3 kg/m) completed two randomised studies, ingesting 2 oz of FR or CB.

Acute lysine supplementation does not improve hepatic or peripheral insulin sensitivity in older, overweight individuals.

Context: Lysine supplementation may have a positive influence on the regulation of glucose metabolism but it has not been tested in the geriatric population.

Objective: We evaluated the impact of acute lysine supplementation using three randomized experimental scenarios: 1) oral glucose alone (control), 2) oral glucose and low-dose lysine (2 grams), and oral glucose and high dose lysine (5 grams) lysine in 7 older (66 ± 1 years/age), overweight/obese (BMI = 28 ± 2 kg/m(2)) individuals.

Methods: We utilized a dual tracer technique (i.

Bed rest promotes reductions in walking speed, functional parameters, and aerobic fitness in older, healthy adults.

Context: The exact relationship between the bed rest-induced loss of skeletal muscle and reductions in muscle strength and physical performance in the older individuals is still unclear.

Objective: We examined the effect of 10 days of bed rest on changes in regional body composition, muscle strength, and functional status, and the relationship between these variables in older individuals.

Design, Participants, And Intervention: Regional body composition was measured using dual energy x-ray absorptiometry.

Bed rest worsens impairments in fat and glucose metabolism in older, overweight adults.

Background: The effects of bed rest on the dysregulation of fatty acid and glucose metabolism have not been addressed in the older population.

Objective: We examined the effect of 10 days of bed rest on fatty acid kinetics and hepatic and peripheral insulin resistance in aging.

Methods: We utilized an octreotide, basal glucagon replacement, multistage insulin infusion, and the concomitant infusion of [6,6 (2)H₂]glucose to derive insulin-mediated suppression of glucose production and insulin-stimulated glucose disposal in nine older, overweight individuals (body mass index 28.

The impact of exercise training compared to caloric restriction on hepatic and peripheral insulin resistance in obesity.

Context: It has been difficult to distinguish the independent effects of caloric restriction versus exercise training on insulin resistance.

Objective: Utilizing metabolic feeding and supervised exercise training, we examined the influence of caloric restriction vs. exercise training with and without weight loss on hepatic and peripheral insulin resistance.

EAA supplementation to increase nitrogen intake improves muscle function during bed rest in the elderly.

Background & Aims: Older individuals are more likely to experience extended hospitalization and become protein malnourished during hospitalization. The concomitant compulsory inactivity results in functional decline. Increasing protein intake in hospitalized patients improves nitrogen balance, but effects on function are unknown.

Influence of exercise intensity on abdominal fat and adiponectin in elderly adults.

To examine the influence of moderate-intensity (50% of VO(2peak)) exercise training (MI) versus high-intensity (75% of VO(2peak)) exercise training (HI) on regional fat distribution and plasma adiponectin, we randomized 18 overweight (body mass index [BMI] = 30 +/- 1 kg/m(2)) elderly (71 +/- 1 years) to HI, MI, or a control group (CON). Subjects enrolled in HI or MI completed a 12-week exercise training protocol designed to expend 1000 kcal/week. Body composition testing was completed prior to and following the exercise training using dual energy X-ray absorptiometry and a computed tomography scan.

Visceral fat and adiponectin: associations with insulin resistance are tissue-specific in women.

Body fatness and its distribution are strongly and independently associated with peripheral insulin action. However, these associations are limited in their ability to predict the independent nature of hepatic and peripheral insulin resistance, especially in obese women. To define the relationships more precisely between regional fat distribution and adiponectin, and hepatic and peripheral insulin resistance, we studied 22 obese (43 +/- 0.

Effects of an ad libitum, high carbohydrate diet and aerobic exercise training on insulin action and muscle metabolism in older men and women.

Background: Previous studies have demonstrated that aerobic exercise training and weight loss have independent effects on insulin-stimulated glucose disposal (ISGD). We hypothesized that ad libitum consumption of a high-carbohydrate diet would result in weight loss and improved ISGD, and that aerobic exercise training would facilitate greater improvements in ISGD compared with diet alone.

Methods: Older participants (13 women, 9 men; age = 66 +/- 1 year) with impaired glucose tolerance were randomly assigned to an ad libitum diet alone (18% fat, 19% protein, 63% carbohydrate) or this diet plus aerobic exercise training (4 d/wk, 45 min/d, 80% VO(2peak)) for 12 weeks.

Exercise-induced changes in insulin action and glycogen metabolism in elderly adults.

Purpose: Although data suggest that physical activity is associated with decreased insulin resistance, recommendations for exercise training are not specific for age or level of obesity. Therefore, we examined the influence of moderate-intensity (50% of VO2max) exercise training (MI) versus high-intensity (75% of VO2max) exercise training (HI) on insulin-stimulated glucose disposal (ISGD) in elderly individuals.

Methods: Following medical examinations, 21 overweight (body mass index = 29 +/- 1 kg x m(-2)) elderly (74 +/- 1 yr) subjects were randomized to 1) HI, 2) MI, or a 3) nonexercising control group.

Human soleus and vastus lateralis muscle protein metabolism with an amino acid infusion.

The calf muscles, compared with the thigh, are less responsive to resistance exercise in ambulatory and bed-rested individuals, apparently due to muscle-specific differences in protein metabolism. We chose to evaluate the efficacy of using amino acids to elevate protein synthesis in the soleus, because amino acids have been shown to have a potent anabolic effect in the vastus lateralis. Mixed muscle protein synthesis in the soleus and vastus lateralis was measured before and after infusion of mixed amino acids in 10 individuals (28 +/- 1 yr).