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.