The Combined Effects of Resistance Training and Flax Oil Supplementation Upon Inflammation in Older Adults
The specific aim is to determine the effect of progressive resistance training and
α-linolenic acid supplementation for decreasing markers of inflammation and improving muscle
mass and strength in older adults. This will be done by comparing older adults who will
participate in the same resistance training program while supplementing their diet with
either α-linolenic acid or placebo.
The hypotheses of this research are:
Resistance training combined with α-linolenic acid supplementation will decrease the
pro-inflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α),
and increase strength and muscle mass more than resistance training and placebo
supplementation in older individuals.
Sixty untrained males and females over 60 years of age will be recruited by newspaper ads.
Subjects will be matched for sex and age and randomly assigned to supplement with 15 g/day
α-linolenic acid (ALA) from flaxseed oil or placebo (corn oil) while participating in
resistance training, 3 times per week for 12 weeks. The 15 g dose was chosen because it was
effective for reducing pro-inflammatory cytokines in healthy adults over 4 weeks (Caughey et
al., 1996). Twelve weeks of resistance training was chosen because it is effective for
increasing muscle mass and strength in older adults (Chrusch et al., 2001). Our sample size
of 30 subjects per group will be sufficient for detecting the expected changes in cytokines
(Caughey et al., 1996) with a power of 80% and alpha level of 0.05. The primary dependent
variables will be the pro-inflammatory cytokines IL-6 and TNF-α. Secondary dependent
variables are chest press and leg press strength, lean tissue mass, and muscle thickness. A
2 (groups) x 2 (time, baseline and 12 weeks) ANOVA with repeated measures on the 2nd factor,
will be used for analyses with alpha level of 0.05.
Methodology: Exercise Training: The exercise training will consist of a progressive
resistance training program designed to increase skeletal muscle hypertrophy by having
participants complete 12 different machine-based resistance exercises. The exercises will
include: chest press, shoulder press, lat pulldown, bicep curl, triceps extension, leg
press, knee flexion, knee extension, hip flexion/extension, and hip abduction/adduction.
The subjects will complete between 3-4 sets of 6-12 repetitions at intensities between
65-80% of their 1 repetition maximum in a progressively overloaded fashion.
Biochemical Measures: Assessment of markers of inflammation will be done by biochemical
blood analysis at baseline and after 12 weeks supplementation combined with resistance
training. Blood will be drawn after an overnight night fast in the morning to account for
changes due to diurnal variation. Approximately 10 mL of blood will be drawn from the
antecubital vein of the arm. Serum will be assessed for the pro-inflammatory cytokines
interleukin-6 and tumor necrosis factor-alpha using ELISA.
Fitness Testing: One repetition maximum (RM) strength tests will be done using chest press
and leg press at baseline and 12 weeks. Subjects will complete a standardized warm-up of
cycling and stretching before the strength test. The testing protocol will allow subjects
to become familiar with the movement patterns of the resistance training machines before
initiating the strength testing trials. Subjects will be gradually progressed to the
maximal load that they can lift for the chest press and leg press. Once the subject is
unable to complete a full repetition, the last successful attempt will be recorded as their
Body Composition: Lean tissue and fat mass will be assessed by dual energy X-ray
absorptiometry, and muscle thickness of the extensors and flexors of the elbows and knees
will be determined by ultrasound at baseline and 12 weeks.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment
Interleukin-6 and tumor necrosis factor-alpha at 12 weeks
Philip D Chilibeck, Ph.D.
University of Saskatchewan
Canada: Health Canada