None listed
Conditions
Brief summary
In accentuated eccentric strength training (AEST), the eccentric (lengthening) contraction phase is accentuated with heavier weights than during the concentric phase, which has shown to result in greater improvements in body composition compared to traditional resistance training methods. However, previous studies have been limited because AEST typically requires another individual to help support the heavier eccentric weight, leading to undesirable lag time and increased risk of injury during the exchange of weights. This preliminary study aims to assess accentuated eccentric strength training, using machines specifically developed for this type of training. Measures of improved body composition, muscle strength, and metabolic health will be taken before and after eight weeks of training in adults between 18 and 65 years. We will examine the effects of AEST coupled with a low-calorie high protein diet on body fat and lean tissue, muscle strength, and long-term glycaemic control, in a community gym setting in adults of three different age groups. Participants will be placed on a low-calorie, high-protein diet to minimise the effects of the expected differences in diets usually followed by our participants. This pilot study aims to obtain data that will allow us to confidently design future rigorous studies to test the hypothesis that AEST improves body composition.
Interventions
Only one cohort will be recruited. Although anecdotal reports suggest that responses to accentuated eccentric strength training differ between three broad age-groups of the adult lifespan, there are insufficient published data to calculate three age-group cutoff points. This preliminary study is expected to determine within-subject changes, and whether age-group differences are detectable. From anecdotal experience, we expect our data will at least reveal a trend towards differences in the exten
Only one cohort will be recruited. Although anecdotal reports suggest that responses to accentuated eccentric strength training differ between three broad age-groups of the adult lifespan, there are insufficient published data to calculate three age-group cutoff points. This preliminary study is expected to determine within-subject changes, and whether age-group differences are detectable. From anecdotal experience, we expect our data will at least reveal a trend towards differences in the extent of physiological responses between a young, middle, and older age group. Specific details of the interventions follow. Accentuated eccentric strength training Performed on proprietary equipment (trade name X-Force) designed to safely conduct accentuated eccentric strength training of upper and lower limb and torso muscles. Procedures consist of a participant "warming up" on a stationary cycle for 5 minutes. An assigned trainer then guides the participant through a short set of 5 to 8 repetitions to the point of momentary muscular failure (MMF), which is the point at which they cannot complete a full repetition after attempting to contract on the concentric phase for 5s. Each participant will do this on each of the nine X-Force machines. Each machine is designed to exercise a single muscle or functionally similar group during a defined range and extent of movement, e.g., knee extension through 90 degrees, elbow flexion through a full range of movement. Experienced strength trainers (minimum of 1 year of training members) who specialise in eccentric strength training will be assigned to the study. The frequency of training sessions will be no more than twice per week, each session will take 20-30 minutes. Training will be conducted in the BodyTech gym located in Nugent St Auckland. A unique feature of the X-Force machines is that positional settings and initial movement resistance can be adjusted to each individual, thereby minimising undesired forces being applied to joints and muscles. Importantly, the resistance to concentric and eccentric muscle contraction movements is adjusted so that the resistance applied during eccentric contraction is 40% higher than the resistance applied during concentric contraction. Research indicates accentuated eccentric training of muscles improves muscle strength and mass, as well as metabolic measures such as blood pressure, and blood glucose. Hypocaloric Diet: During the 8-week training programme, all the participants will be following the same hypocaloric, high protein diet which they will complete at home. Each participant will be given a digital “Clean Eating Plan” eBook which is a complete reduced-calorie diet (hypocaloric diet) designed to work in conjunction with a high-intensity strength training programme. Each participant will be shown how to use the programme and adhere to the diet by one of the Personal Trainers or one of the experimenters (Jessica Cadenhead, Peter Rana, Sarah Peek) at BodyTech Gym. The recipes have been expertly devised by a registered nutritionist and lecturer in nutrition (Nicola Page, Registered Nutritionist) and apply the latest scientific evidence for best nutritional practices and strategies. The Clean Eating Plan consists of easily implemented guidelines to help you create a workable personal eating plan, which includes a week-by-week caloric intake schedule. For females, the daily caloric intake is 1,300kcal/day on a non-workout day and then 1,500kcal/day on the two workout days. For males, the daily caloric intake is 1,500kcal/day on a non-workout day and then 1,700kcal/day on the two workout days. The additional calories on the workout days account for a post-workout protein supplement (protein shake) which is key to this eating plan. The plan also includes how much protein the participant should be consuming based on their ideal weight and age. For those under 40 years old, it is recommended to consume 1.2g/kg of protein per day and for those over 40 years old, it is recommended to consume 1.5g/kg due to the aging effect of utilizing amino acids for muscle building processes. The participants will be asked to complete food diaries for 3 days of each week to ensure they are complying with the diet. Participants will also be asked questions at the beginning of each strength training session by one of the personal trainers regarding diet adherence. Adherence to both strength training and diet in this preliminary study will be documented to assist the design of a future controlled clinical trial.
Sponsors
University of Auckland
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 69 Years
Healthy volunteers
Yes
Inclusion criteria
Inclusion: Men and women aged 18-69 years old who are members of BodyTech Gym.
Exclusion criteria
People who have a known health condition or injury that will prevent them from exercising to momentary muscular failure on all training equipment, or who have been advised not to engage in resistance exercise or any exercise training by their primary health care physician. Excluded conditions include people with uncontrolled hypertension, chronic heart failure, musculoskeletal disorders, or cancer. Participants who are currently on a reduced-calorie diet will also be excluded, for example, Weight Watchers or Jenny Craig programmes.
Outcome results
None listed