The present study is a randomized double-blind placebo controlled repeated measures design, with sampling of the cohorts on multiple occasions. Upon obtaining informed consent participants will be randomized into one of six groups:
Healthy younger males - n=20; Healthy older males - placebo n=10, supplement n=10; Sarcopenic older males, placebo, n=20, supplement n=20;
Take home resistance training program The older adult male groups will be provided with a progressive resistance training program which will use exercise bands (Therabands®, Akron, Ohio) and consist of six upper body and six lower body exercises, which will be performed three times per week for 12 weeks without supervision at home. Each session will consist of active warm-up (5min), resistance training with elastic tubing (45min), and cool down (5min). Briefly, the resistance exercises will be performed using elastic tubing for chair squats, hip flexions, leg extensions, leg flexions, ankle dorsiflexion, wall push-ups, back rows, shoulder abductions, triceps extensions, and forearm flexions. Ankle plantar-flexions and abdominal curl-ups will be performed using body weight as resistance. Each participant will be given an exercise instruction booklet and a set of five elastic tubes offering different resistances. Prior to beginning the program trained staff will meet with participants and will teach them how to properly perform exercises in addition to determining the starting elastic tubing size. Furthermore, participants will perform one set of each exercise during weeks 1 and 2, two sets of each exercise during weeks 3 and 4, and three sets of lower body and two sets of upper body exercises during the remaining weeks. Participants will be instructed to move to the next larger tubing size when they can perform 12 repetitions with good exercise form during their last set. This progression will be monitored by the project staff mid way through the study over the phone.
Study products Study products will be provided by Infinit Nutrition Canada (Windsor, Ontario) to all older male subjects, however the young males will only act as baseline controls. The composition of the study products is displayed above in the general experimental design. Both products are similar in taste and appearance and provide an energetic value of ∼200 kcal per serving in a volume of 200 mL. Participants will be asked to consume 1 serving daily of the study product throughout the 12-wk intervention period. Participants will consume their serving at approximately the same time of day, but preferably before breakfast. Participants will be instructed to consume the supplement as a single bolus within 5-10 min. Subjects will also also be provided an omega-3 supplement (or placebo, if they are assigned to the placebo arm) and be instructed to consume 2 teaspoons at the same time as their nutritional supplement. Participants will be instructed to record product intake in a diary to check compliance. To maintain the double-blind nature of the experiment, the placebos, which contains microcrystalline cellulose or safflower oil, will be matched in size and appearance.
Three day weighed food record Participants will be asked to record everything that they consumed for 3 nonconsecutive days: 2 week-days and either a Saturday or a Sunday. On completion of the food record, it will be analyzed using a commercially available computerized database software (Nutribase version 11.5, Cybersoft Inc., Phoenix, AZ, USA). Food items will be aggregated into the following categories: fruit (e.g., fresh/frozen, tinned, juice), vegetables (e.g., fresh/frozen, canned), dairy products (e.g., milk, yoghurt, cheese), breads and cereals (e.g., bread, breakfast cereal, rice, pasta), meats and alternatives (e.g., red meat, poultry, fish, pork, processed meat, tofu, eggs, nuts) and extra foods (e.g., hamburger, pizza, meat pies, chocolate, cake, ice cream, jam, biscuits, crackers, crisps, alcohol).
Pedometer Participants will be given a wearable activity tracker, and instructed on weight training days to aim for 5,000 steps and on all other days to try and reach 10,000. All participants will record their daily totals for subsequent analysis.
Dual X-ray absorptiometry (DXA) and blood pressure A DXA scan is a non-invasive procedure requiring the participant to only lay still on a padded table. It is a fast procedure that provides a variety of body composition variables (bone mass/area/density, fat mass, and fat free mass). The DXA scan exposes individuals to low levels of radiation, approximately 0.18 millirem. According to the United States Nuclear Regulatory Commission, Americans receive approximately 620 millirem each year, half of which is due to environmental background radiation. Radiation exposure can be due to medical treatments or procedures, like X-Ray or MRI's, food, sun exposure, etc. Any exposure to radiation can increase the risk of cancer. In the present study, body composition will be assessed using DXA scan (GE Lunar Prodigy, Madison, WI) and a software program for adults (encore Version 9.15.010). Fat free mass (FFM), fat mass (FM) and bone mineral density (BMD) of the entire body will be recorded. Arterial blood pressure (i.e., systolic \[SBP\] and diastolic \[DBP\]) will be measured during rest with a stethoscope (Marshall Nurse Stethoscope, Riverside, Ill., USA) and sphygmomanometer (MDF Instruments Direct Inc., Agoura Hills, Calif., USA).
Muscle biopsies Participants will arrive in the morning in the fasted state and rest quietly in the supine position for 10 minutes. A muscle biopsy will then be taken from the vastus lateralis using local anaesthetic. Samples will be dissected free of connective tissue and immediately partitioned for subsequent analysis (\~ 25 mg) for RNA, a small piece (\~ 10 mg) will be placed into chilled glutaraldehyde for subsequent electron microscopic evaluation, \~ 20 mg will be frozen for mtDNA deletions, and \~ 50 mg will be frozen for enzyme and protein analysis. The investigators will measure muscle anabolic signaling as previously reported.
Blood sampling A total of 100 mL blood will be taken from the antecubital vein and drawn into evacuated tubes with heparin used for plasma collection and non-treated tubes will be used to collect serum.
Waist and hip circumference measures For waist circumference measurement, the participant will stand with arms at the sides, feet together, and abdomen relaxed. Using a Gulick tape measure, a horizontal measure will be taken at the narrowest part of the torso (above the umbilicus and below the xiphoid process). Obtaining a horizontal measure directly above the iliac crest enhances standardization according to The National Obesity Task Force. For hip circumference measurement, the participant stands erect and feet together, a horizontal measure is taken at the maximal circumference of buttocks.
Physical performance battery A total of four functional tasks will be performed once using a stopwatch that records times to an accuracy 1/100 of a second. First, the 6-minute walk test will involve participants walking as fast as possible around a 20m track for 6 minutes and distance will be measured to the closest meter. Next, the standard 4-stair climb test will involve participants climbing 4 stairs as fast as possible. A 5x sit-to-stand test will involve participants performing a series of consecutive rising and sitting positions from a sturdy, armless plastic chair secured against a wall and with arms crossed at the chest. Finally, the chair rise-and-walk test will involve participants starting from a seated position, standing up and walking as quickly as possible in a predetermined straight line to a pylon 9.14m, while going around the pylon, and returning to their original seated position.
Leg press 1RM Assessment procedures for determining lower body strength using leg press exercise equipment (Cybex Eagle ®, Medway, MA) will require the participant to sit in the leg press machine with the right foot and left foot on the weight platform. The seat and back pad will be adjusted so that feet are flat on the platform hip-width apart, toes slightly angled out, and legs parallel to each other. The interviewer will then instruct the participant to grasp the handles or sides of the seat and extend their legs leaving just a slight bend in the knee. Next, the participant will remove the racking mechanism from the platform and grasp the handles or seat again. The participant will begin with a selected weight that is within their perceived ability, approximately 60 to 80% of maximum capacity (make an educated guess). The participant will lower the platform slowly and controlled towards the chest, keeping the hips and buttocks on the seat, and the back flat against the back pad. Once the thighs are parallel to the platform the participant will extend the legs, pushing the weight back to the start position as hard and as fast as possible. The participant will be instructed to not allow their hips to shift to one side, the buttocks to rise, or knees to move inward or outward during this exercise. The interviewer will also instruct the participant to keep heels flat and not allow the knees to go beyond the toes. Once the repetitions are completed, the participant will replace the racking mechanism and exit the leg press. These procedures were adapted from procedures described by the National Strength and Condition Association (2008) and the American College of Sports Medicine (2013).
Hand grip strength (MVIC) Hand grip strength will be measured using an isometric dynamometer (JAMAR®, Sammons, Bolingbrook, IL). The grip width will be adjusted to hand size and with arm flexed at 90°, the participant will perform three X 5 s efforts with a one min rest between trials.
Knee extension (MVIC) Isometric knee extension will be measured by mechanical dynamometry (Biodex System 3, Biodex Medical Systems, Shirley, NY). Participants will be positioned into the machine with the knee flexed at 90° and perform three X 5s maximal voluntary contractions with 30s rest between each trial.
SF-36 Quality of health Questionnaire The RAND 36-Item Health Survey (Version 1.0) taps eight health concepts: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. It also includes a single item that provides an indication of perceived change in health.
