Anorexia: Light Weightlifting is all but Worthless

Does resistance training improve the functional capacity and well being of very young anorexic patients? A randomized controlled trial. del Valle MF, Pérez M, Santana-Sosa E, Fiuza-Luces C, Bustamante-Ara N, Gallardo C, Villaseñor A, Graell M, Morandé G, Romo GR, López-Mojares LM,Ruiz JR, Lucía A. J Adolesc Health. 2010 Apr;46(4):352-8.

We determined the effects of a 3-month low-moderate-intensity strength training program (2 sessions/week) on functional capacity, muscular strength, body composition, and quality of life (QOL) in 22 young (12-16 yrs) anorexic outpatients.

Patients were randomly assigned to a training or control group (n=11 [10 females] each). Training sessions were of low intensity (loads for large muscle groups ranging between 20%-30% and 50%-60% of six repetitions maximum [6RM] at the end of the program). We measured functional capacity by the time up and go and the timed up and down stairs tests. Muscular strength was assessed by 6RM measures for seated bench and leg presses. We estimated percent body fat and muscle mass. We assessed patients’ QOL with the Short Form-36 items.

The intervention was well tolerated and did not have any deleterious effect on patients’ health, and did not induce significant losses in their body mass. The only studied variable for which a significant interaction (group x time) effect was found (p=.009) was the 6RM seated lateral row test.

Low-moderate-intensity strength training does not seem to add major benefits to conventional psychotherapy and refeeding treatments in young anorexic patients.

My comments

This is one of those studies and subsequent findings, where any strength coach would look at it and say, “duh.” However, it’s interesting to see the outcomes quantified and compared to the same authors more recent paper, where intense/heavy weight training had very beneficial performance outcomes in patients with anorexia.

The researchers chose reasonably good exercises; bench press, shoulder press, leg extension, leg press, leg curl, abdominal crunch, low back extension, arm curl, elbow extension, seated row, and lat pulldowns, which were essentially the same exercises as the newer paper. The main difference was that in the study that worked, they did 3 sets of 8-10 reps (very similar to what a lot of strength would do) while this study did only one set of 15 reps with 20-60% of the 6 RM (a 6 RM being only ~85% of a 1 RM to begin with) nothing anyone who knows how to lift would recommend.

The big caution, apparently, being girls with anorexia have weakened bones and muscles and thus can’t handle heavy weights. However, what I think should have been apparent is that when you are basing intensities off of a RM (repetition maximum, 1 rep, 6 or whatever) a weakened person is going to have a lower max, and thus percents of it are already going to be lower, such that the safety is already built in. Working 20-60% of a 6 RM (which is already only 85% of a 1 RM) is just too light to do anybody any good, which is exactly what they found.

I still like this paper in context with the other. This paper shows that higher intensity weights not only work as per the primary authors later study, but they are necessary, because lighter weights just don’t cut it. There were similar results with intense lifting recently being found in elderly women with osteoporosis, or pretty much anybody training for fitness. Weights are supposed to be heavy, that’s why they call them weights.

As always, if you have any further questions or need for clarifications, please don’t hesitate to ask. Being aware that some of my blog ideas are contentious and occasionally a bit out of the field of my expertise, I encourage my readers to come forth with any questions/comments that are of interest or concern. Your comments are valued and welcomed.

Chad Reilly is a licensed physical therapist, located in North Phoenix, practicing science based medicine with treatment protocols unique and effective enough to proudly serve patients from Phoenix, Scottsdale, Mesa, Chandler, Tempe, Peoria, and Glendale.

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