Journal of Adolescent Health 46 (2010) 352–358

Original article

Does Resistance Training Improve the Functional Capacity and Well

Being of Very Young Anorexic Patients? A Randomized Controlled Trial

Marıa Fernandez del Valle, B.Sc.a, Margarita Perez, M.D., Ph.D.a, Elena Santana-Sosa, B.Sc.a,Carmen Fiuza-Luces, B.Sc.a, Natalia Bustamante-Ara, B.Sc.a, Cristian Gallardo, B.Sc.a,

Angel Villasenor, Ph.D.b, Montserrat Graell, M.D.b, Gonzalo Morande, M.D.b,Gabriel R. Romo, Ph.D.c, Luis M. Lopez-Mojares, M.D., Ph.D.a, Jonatan R. Ruiz, Ph.D.d,

and Alejandro Lucıa, M.D., Ph.D.a,*aUniversidad Europea de Madrid, Spain

bServicio de Psiquiatrıa, Hospital Infantil Universitario Nino Jesus, Madrid, SpaincINEF, Universidad Politecnica de Madrid, Spain

dDepartment of Biosciences and Nutrition at NOVUM, Unit for Preventive Nutrition, Karolinska Institutet, Huddinge, Sweden

Manuscript received June 1, 2009; manuscript accepted September 9, 2009

Abstract Purpose: We determined the effects of a 3-month low–moderate-intensity strength training program

No author received

produce the manuscrip

*Address correspo

Europea de Madrid, 2

E-mail address: al

1054-139X/10/$ – see

doi:10.1016/j.jadoheal

(2 sessions/week) on functional capacity, muscular strength, body composition, and quality of life

(QOL) in 22 young (12–16 yrs) anorexic outpatients.

Methods: Patients were randomly assigned to a training or control group (n¼ 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.

Results: 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 3 time) effect was found (p¼ .009) was the 6RM seated lateral row test.

Conclusions: Low–moderate-intensity strength training does not seem to add major benefits to

conventional psychotherapy and refeeding treatments in young anorexic patients. � 2010 Society

for Adolescent Medicine. All rights reserved.

Keywords: Resistance training; Anorexia nervosa; Strength tests

Anorexia nervosa (AN) is a life-threatening complex

psychiatric disorder that involves the ‘‘relentless pursuit of

thinness’’ [1] by restricting energy intake while increasing

energy expenditure with exercise [2]. Whether regular, super-

vised exercise can be incorporated into the therapeutic arma-

mentarium against AN is a subject of current debate.

Controversy arises from the fact that excessive exercise has

any honorarium, grant, or other form of payment to

t.

ndence to: Alejandro Lucia, M.D., Ph.D., Universidad

8670 Villaviciosa de Odon, Madrid, Spain.

ejandro.lucia@uem.es

front matter � 2010 Society for Adolescent Medicine. All

th.2009.09.001

been postulated as a causal factor of AN, and it can be asso-

ciated with a poor evolution of the established disorder [3,4].

Earlier reports showed several exercise-related benefits in

anorexic patients. A refeeding program allowing exercise

practice was more acceptable to the patients with no differ-

ences in rate of weight gain compared with a more strict

program [5]. Vandereycken et al [6] recommended the use

of recreational, group activities such as yoga, Tai Chi, or

dance to help patients improve their self image. A controlled

trial including patients between the ages of 17 and 45 years

did not show significant differences in quality of life

(QOL)–related outcomes between a training and control

group after a 3-month period of stretching, resistance, and

rights reserved.

M.F. del Valle et al. / Journal of Adolescent Health 46 (2010) 352–358 353

aerobic exercises [7]. Tokomura et al [8] reported no adverse

effects on weight, recovery of menstruation, or eating

disorder recurrence in anorexic women after a 6- to 12-month

aerobic cycle–ergometry program. Their intervention was

well tolerated and contributed to reduce emotional stress in

the patients.

One important, often under-recognized, health problem

associated with AN is metabolic myopathy, which is likely

secondary to severe protein malnutrition and is characterized

by selective type-2 fiber atrophy and reduced levels of

strength [9]. Thus, resistance training seems the most clini-

cally appropriate type of exercise program for anorexic

patients. In this type of training, muscles contract against

an external resistance with the expectation of increases in

strength, tone, mass, and/or endurance, for example, using

barbells, elastic bands, weight training machines, or own

body weight. Szabo and Green [10] showed that, compared

with a nonexercising group, the changes in body composition

observed in hospitalized anorexic women (mean age, 23

years) during a refeeding protocol were unaffected by an

8-week light resistance training program. The intervention

induced significant increases in the knee extensors’ peak

force of the exercisers compared with controls [11]. One

benefit of resistance compared with aerobic training is that

caloric expenditure is usually lower [12]. Another benefit is

the greater effect on bone density [13]. A question of prac-

tical applicability that remains to be answered is whether

the potential benefits of resistance training in anorexic

patients result in improved functional capacity during muscle

tasks of daily living (e.g., climbing stairs, standing up from

the lying or sitting position). It would be also clinically useful

to determine whether young anorexic patients (�16 years)

benefit from resistance training interventions. This would

support the notion that resistance exercises have a therapeutic

value even in the youngest populations. Recent research

showed the benefits of resistance training interventions in

pediatric cancer patients with myopathy associated with

bone marrow transplantation [14]. Finally, it remains to be

determined whether, in anorexic outpatients, an easily appli-

cable program (e.g., two sessions/week after psychological

therapy) is sufficient to induce health and functional benefits.

The purpose of this randomized controlled trial was to

determine the effects of a 3-month resistance training program

(two sessions/week) on the functional capacity, muscle

strength, body composition, and QOL of young anorexic

outpatients (�16 years).

Table 1

Anthropometric characteristics since diagnosis by group

Control (n¼ 11) Training (n¼ 11)

Lowest weight since diagnosis (kg) 41.1 (4.4) 39.3 (9.1)

Lowest BMI since diagnosis (kg/m2) 15.5 (1.0) 14.7 (1.4)

Weight gain since diagnosis (kg) þ5.9 (3.2) þ8.4 (3.4)

BMI at the start of the study 18.2 (1.5) 18.7 (1.7)

Data are means (SD).

BMI¼ body mass index.

All p > .1 for group comparisons.

Methods

Participants

We obtained written informed consent from all partici-

pants and their parents. The research protocol was reviewed

and approved by the Children’s Hospital Nino Jesus (Madrid,

Spain). The present randomized control trial was performed

between January and March 2007, following the guidelines

of the Declaration of Helsinki, last modified in 2000. We

registered the study in www.clinicaltrials.gov (ID:

NCT00829946).

From the database of the Children’s Hospital Nino Jesus(Madrid, Spain), we contacted 35 Spanish (Caucasian) young

outpatients of both genders with restrictive AN. They all met

the following inclusion criteria: (i) diagnosis of restrictive

AN [15] in the aforementioned hospital; (ii) age �16 years;

(iii) undergoing intrahospital psychotherapy and dietary

counseling (two visits/week) in this hospital; and (iv) body

mass index (BMI) >14.0 kg/m2 [16]. A total of 22 outpa-

tients (20 female [Tanner stage II–IV], 2 male [Tanner stage

IV]; age 12–16 years) agreed to participate in the study. They

were randomly assigned with a block on gender and Tanner

stage for females (II or III–V) to either a training or control

group (n¼ 11 [10 females] each). The participant randomiza-

tion assignment followed an allocation concealment process

[17,18].

The mean age (standard deviation, range) in the training

and control group was 14.7 (0.6, 14–16) years and 14.2

(1.2, 12–16) years. The number of girls in Tanner stages III

and IV was 2 and 8 in the training group and 3 and 7 in the

controls, respectively. Time elapsed since initial diagnosis

was 42 (11) and 72 (31) days in the training and control

group, respectively. The main anthropometric characteristics

of the participants since the time of diagnosis are shown in

Table 1.

Physical activity and dietary intake assessment

Participants in the nonexercise control group were required

to maintain their level of physical activity (PA) during the

study period. To ensure that the level of PA apart from training

sessions was similar in the two groups, we assessed the PA

levels in all participants during the intervention period

(excluding training sessions) using a uniaxial accelerometer

(Actigraph MTI, model GT1 M, Manufacturing Technology

Inc., Fort Walton Beach, FL). Details on this methodology

are provided elsewhere [19]. At least 7 days of recording

(Monday–Sunday) with a minimum of 10-hour registration

per day was set as an inclusion criterion. The time sampling

interval (epoch) was set at 60 seconds. A measure of average

PA intensity was expressed as the sum of recorded counts per

epoch divided by total daily registered time (i.e., counts per

minute [cpm]). The time engaged in low, light, moderate,

M.F. del Valle et al. / Journal of Adolescent Health 46 (2010) 352–358354

vigorous, and very vigorous PA was calculated upon the cut-

off limits published elsewhere [19,20].

We recorded calorie intake (kcal/kg/day) in all partici-

pants using 3-day food records at the start and end of the

intervention period. Daily calorie intake was in the range of

2000–2500 kcal/day depending on patients’ weight. Energy

intake consisted of w55% carbohydrate, w30% protein,

and w15% fat.

Intervention

Participants in the intervention group were enrolled in two

training sessions per week for 12 weeks. Each session lasted

60–70 minutes and started at w11:30 AM, after the intraho-

spital psychotherapy session. The program was individually

supervised (one instructor for every three participants).

Each session started and ended with a low-intensity warm-

up and cool-down period (10–15 minutes each), each con-

sisting of stretching exercises involving all major muscle

groups. The core portion of the session included 11 strength

exercises engaging the major muscle groups, that is, bench

press, shoulder press, leg extension, leg press, leg curl,

abdominal crunch, low back extension, arm curl, elbow

extension, seated row, and lateral pull-down. The participants

performed one set of 10–15 repetitions until volitional fatigue

(w20-s duration) per exercise, with resting periods

(including stretching exercises) of 1–2 minutes [21]. The

load was gradually increased as the strength of each child

improved, that is, from 20%–30% of 6 repetition maximum

(6RM) at the start of the program to 50%–60% of 6RM at

the end. For each exercise, the load was increased from one

session to the next one when the subjects could complete

15 repetitions. Participants also performed isometric contrac-

tions of large muscle groups (six sets of three repetitions

each, 20–30-s duration per repetition) with their own body

weight (for lower body exercises) or barbells (1–3 kg) for

upper body.

All training sessions were performed in an intrahospital

gymnasium (Children’s Hospital Nino Jesus of Madrid,

Spain) that includes weight training machines that are specif-

ically built for the body size of children and adolescents

(Strive Inc, PA).

Outcome measures

Anthropometry. Standing height was measured to the nearest

.1 cm with a clinical stadiometer (Asimed T2, Barcelona,

Spain) while children were standing barefoot. Body mass

was determined to the nearest .05 kg using a balance scale

(Ano Sayol S.L., Barcelona, Spain) with the subject in their

underwear. BMI was calculated as weight divided by height

(kg/m2). Skinfold thickness was measured with a Harpenden

caliper at triceps, abdominal, and suprailiac area at the left side

of the body [22]. We estimated percentage body fat [23] and

total muscle mass (kg). The latter was calculated following the

equation developed by Lee et al [24]: Muscle mass

(kg)¼Height (m) 3 (.00744 3 CAG2 þ .00088 3 CGT2 þ.00441 3 CCG2)þ 2.4 3 gender – .048 3 age (yrs)þ 7.8,

where CAG is corrected arm girth; CTG, corrected thigh girth;

and CCG, corrected calf girth, and gender equals 1 for male

and 0 for female. Limb girths were corrected for subcutaneous

adipose tissue thickness as detailed elsewhere [24].

All anthropometric measurements were performed by the

same experienced researcher.

Muscular strength. Muscular strength was assessed in the

upper and lower body following a standardized strength

testing protocol using the same variable resistance weight

machines that were used in training sessions. Lower body

strength was assessed with a 6RM seated bench press and

with seated lateral row, and upper body strength was assessed

with a 6RM seated leg-press [25]. We have previously used

the same 6RM test in diseased children with very weak

muscles because of the effects of pediatric cancer and chemo-

therapy [14,26]. The 6RM value was measured in kilograms

and is described as the maximum strength capacity to

perform six repetitions until momentary muscular exhaustion

[25]. The testing protocol consisted of three warm-up sets at

50%, 70%, and 90% of the perceived 6RM separated by

1-minute resting periods [25]. A 2-minute rest period

followed the last warm-up set after which a 6RM attempt

was made at 100%–105% of perceived 6RM. The load was

adjusted depending on the load needed to perform the last

warm-up set at 90% of the perceived 6RM. If the first 6RM

attempt was successful, the load was increased by 2.5%–

5% and after 2-minute rest another 6RM attempt was

made. If the second 6RM attempt was successful, a second

testing session was scheduled after 24-hour rest period. If

the first 6RM attempt was not successful, the load was

decreased 2.5%–5% and after 2 minutes of rest another

6RM attempt was made. If the second 6RM attempt was

successful, the weight used was considered the 6RM. If the

second 6RM attempt was not successful, another testing

session was scheduled after 24 hours of rest. Each subject

was instructed to perform each exercise to momentary

muscular exhaustion. The repetitions that were not performed

with a full range of motion were not counted.

Functional mobility. To measure children’s functional

mobility, we used the Time Up and Go (TUG) test of 3 and

10 m and the Timed Up and Down Stairs (TUDS) test

[14,27]. Both types of tests are reliable and valid in healthy

children and also in children with various diseases or disabil-

ities [27,28]. The TUG 3-m and 10-m tests are measures of

the time needed to stand up from a seated position in a chair,

walk 3 and 10 m, respectively, turn around, return to the

chair, and sit down. For the TUDS, we measured the time

taken to ascend and descend 12 stairs [14,27]. All participants

used a hand railing while ascending and descending the stairs

to diminish the risk of falling.

Before the start of the study all subjects underwent

a familiarization period in order to minimize the influence

M.F. del Valle et al. / Journal of Adolescent Health 46 (2010) 352–358 355

of a possible learning effect on the muscular strength and

functional tests (because of improvement of technique and

coordination or diminishment of muscle inhibition). It con-

sisted of two w50-minute sessions per week for a total of

2 weeks. Each session was preceded by a warm-up and ended

with a cool-down of the same activities and duration used

during the training period of the study. Each familiarization

session consisted of two to three sets of one to three repeti-

tions of the exercises (seated bench press, seated lateral

row, seated leg press) used to evaluate muscular strength

and two to three repetitions of the tests used to evaluate func-

tional mobility (TUG and TUDS tests). Test–retest assess-

ments were preceded by a warm-up period including

stretching exercises (w10 min). A high intraclass correlation

coefficient (r � .98; p < .001) between repeated tests was

demonstrated for all of the tests.

Quality of life. We assessed patients’ QOL with the Spanish

version of the Short Form-36 items, which is valid for assess-

ing QOL in Spanish patients with eating disorders and other

psychological comorbidities [29].

All participants performed the tests at the time points cor-

responding to (i) before and (ii) after the intervention period.

Participants consumed their usual breakfast (fruit juice

[w200 cm3] and bowl of cereals [w45 g] with milk

[w200 cm3]) 3 hours before the test protocols described

below. All patients were followed up throughout the entire

study period and underwent the same pre- and poststudy eval-

uations. No participant moved from the control group to the

intervention group or vice versa.

Table 2

Physical activity levels by group (excluding training sessions)

Control (n¼ 11) Training (n¼ 11)

Average intensity PA (cpm) 409.1 (95.1) 444.3 (124.6)

Low PA (min/day) 1231.1 (102.2) 1282.4 (57.2)

Data Analysis

We used a two-factor (group, time) analysis of variance

with repeated measures to assess the training effects on the

outcome variables (anthropometric variables, performance

in functional capacity and strength tests, and QOL). For

each variable we reported the p value corresponding to the

main group (between-subjects), time (within-subjects), and

interaction (group 3 time) effects. In post hoc analyses,

and to prevent type I error, we calculated only the p value

for within-group differences when a significant interaction

effect was present. With regard to potentially confounding

variables (i.e., calorie intake and PA levels), we used the

aforementioned analysis for comparing mean daily calorie

intake between both groups at the start and end of the study,

and we applied a Student unpaired t test to compare mean PA

levels.

The level of significance was set to � .05 and all data are

expressed as mean (standard deviation).

Light PA (min/day) 157.1 (94.1) 103.2 (36.1)

Moderate PA (min/day) 35.2 (23.9) 31.5 (35.8)

Vigorous PA (min/day) 11.4 (7.4) 17.7 (16.9)

Very vigorous PA (min/day) 4.7 (4.9) 5.4 (6)

Data are means (SD).

cpm¼ counts per minute; PA¼ physical activity.

All p > .1 for group comparisons.

Results

There were no protocol deviations from the study as

planned. The final number of participants included as valid

study participants, that is, with a 100% return for follow-up,

was 11 in each group. Of the 11 participants in the interven-

tion group, nine completed all the planned training sessions.

We noted no major adverse effect or health problem in any

study participant.

There were no differences in the mean levels of PA

between both groups (Table 2). Likewise, the daily calorie

intake was also similar at the start (51.0 [7.4] and 52.4

[7.2] kcal/kg/day in training and control groups, respectively)

and at the end of study (52.4 [8.3] and 52.7 [7.5] kcal/kg/day

in training and control groups, respectively) (p¼ .662 for

group, p¼ .770 for time, and p¼ .320 for group 3 time

interaction).

We observed no significant differences, between or within

groups, in anthropometric variables (Table 3). Dynamic 6RM

strength significantly improved with training for the seated

lateral row test (p¼ .009 for the interaction effect) but no

actual improvement solely attributable to the training inter-

vention was noted in the remaining strength/functional tests

(Table 4). As for QOL, we observed no significant interaction

effect and hence no intervention-attributable improvement

(Table 5).

All of the aforementioned results did not materially

change when we excluded the boy from each group in the

analyses.

Discussion

The main finding of our study is that a low–moderate-

intensity resistance training program performed in a hospital

setting does not induce overall significant gains in the func-

tional capacity (included aerobic capacity) of very young

(�16 years) anorexic outpatients nor in their ability to cope

with physical activities of daily living. An actual improve-

ment attributable to the training intervention (i.e., with

a significant interaction effect) was observed only for the

seated lateral row test. Although it did not significantly

improve patients’ QOL, the training intervention was well

tolerated, and it did not have any deleterious effects on

patients’ health and did not induce significant losses in their

weight or BMI. Future research might determine whether

programs of longer duration (>3 months), higher frequency

(more than two sessions per week), or higher loads (>60%

of 6RM) are necessary in young anorexic outpatients to

Table 3

Effects of 3-month resistance training program on anthropometric variables

Group Pre Post p (Group effect) p (Time effect) p (Interaction effect)

Weight (kg) Control 46.6 (5.5) 47.2 (5.3) .805 .766 .347

Training 48.2 (8.8) 47.0 (8.6)

BMI (kg/m2) Control 18.2 (1.5) 18.3 (1.6) .821 .424 .543

Training 18.7 (1.7) 18.2 (2.2)

Muscle mass (kg) Control 19.8 (3.0) 20.4 (3.0) .635 .276 .539

Training 20.7 (4.7) 20.8 (3.1)

Body fat (%) Control 13.8 (2.6) 13.9 (2.4) .692 .372 .247

Training 14.8 (2.9) 13.7 (3.3)

Data are means (SD)

BMI¼ body mass index.

M.F. del Valle et al. / Journal of Adolescent Health 46 (2010) 352–358356

induce major improvements in their functional capacity,

muscular strength, and QOL. Nevertheless, it is noteworthy

that more demanding programs might not be easily appli-

cable in very young patients with AN.

Our findings on body composition were limited by the fact

that we used estimation equations to estimate muscle and fat

mass, yet this method might not be sensitive enough to detect

small changes in muscle mass (� 63% in this study). It is

likely that the use of more advanced and accurate techniques

to assess body composition such as underwater weighing, air

displacement plethysmography, or dual-energy x-ray absorp-

tiometry may help to better elucidate the effect of the inter-

vention on these patients. Unfortunately, for practical

reasons this option was not possible in the present study.

The difference between groups in the mean time elapsed

since diagnosis (42 and 72 months in the training and control

group, respectively), might have influenced, at least partly,

some of our results. However, it must be kept in mind that

main outcome variables (such as anthropometric data or

functional capacity) were similar in the two groups at the start

of the intervention. On the other hand, there were several

novelties and strong methodological aspects in our random-

ized controlled trial compared with previous pioneer research

in the field using resistance training (also two weekly

Table 4

Effects of a 3-month resistance training program on functional capacity and muscu

Group Pre Post

Functional capacity

TUDS test (s) Control 6.5 (0.5) 6.0 (0.7)

Training 6.3 (0.6) 5.8 (0.4)

TUG test 3 m (s) Control 4.2 (0.4) 4.0 (0.3)

Training 3.9 (0.3) 4.0 (0.4)

TUG test 10 m (s) Control 9.7 (0.8) 9.4 (0.8)

Training 9.0 (0.7) 8.9 (0.7)

Muscular strength

Bench press (kg) Control 46.0 (7.9) 52.2 (10.2)

Training 49.3 (10.1) 52.0 (6.6)

Leg press (kg) Control 94.1 (21.3) 103.4 (24.9)

Training 99.3 (12.5) 111.6 (20.1)

Seated row (kg) Control 46.0 (11.8) 46.9 (11.3)

Training 45.4 (5.7) 59.0 (13.7)*

Data are means (SD).

TUDS¼ Timed Up and Down Stairs test; TUG¼ Timed Up and Go test.

* p¼ .002 for Pre vs. Post in the Training group (p¼ .854 within Controls).

sessions) in older (>15 years) anorexic patients [10,11].

Our participants underwent a thorough familiarization period

before performing the baseline functional and/or strength

tests and performed a second test to assess testing reliability.

A familiarization period to eliminate learning effects and

assess the reliability of pretraining tests is necessary to accu-

rately determine the effects solely attributable to training on

muscular strength [30]. Otherwise, potential increases in

muscle strength could be artificially inflated. Instead of

measuring peak muscle force [11], we assessed the effects

of exercise training on (i) functional tests of practical applica-

bility, that is, reflecting the ability to perform lower-body

functional living tasks involving rapid movements (TUG

and TUDS tests), and (ii) submaximal strength (6RM).

Improvements in maximal dynamic strength would not be

of great practical relevance for nonathletes and particularly

in persons with disease conditions such as those studied

here. Maximal strength is not a main determinant of

a patient’s ability to perform daily physical activities, which

are mostly submaximal strength tasks such as climbing stairs

or sitting and rising from a chair.

Myopathy resulting from severe protein malnutrition and

reduction of muscular strength is an important clinical

problem in anorexic patients [9]. Thus, resistance (strength)

lar strength

p (Group effect) p (Time effect) p (Interaction effect)

.366 .001 .964

.196 .196 .143

.040 .175 .623

.801 .104 .634

.424 .033 .683

.239 .005 .009

Table 5

Effect of a 3-month resistance training program on quality of life

Group Pre Post p (Group effect) p (Time effect) p (Interaction effect)

Physical function Control 83.2 (17.6) 88.9 (19.8) .356 .642 .164

Training 93.2 (7.5) 90.4 (11.9)

Physical role Control 45.6 (39.8) 73.1 (33.1) .192 .008 .500

Training 67.6 (21.1) 83.5 (22.7)

Pain Control 59.7 (26.5) 73.9 (18.5) .001 .440 .070

Training 95.6 (7.4) 91.3 (14.9)

General health Control 52.2 (21.0) 56.2 (20.4) .034 .751 .978

Training 70.7 (14.5) 72.3 (20.4)

Vitality Control 51.3 (33.5) 57.0 (20.7) .031 .912 .578

Training 76.7 (15.3) 72.2 (23.3)

Social function Control 49.4 (28.3) 67.5 (19.7) .068 .012 .828

Training 66.1 (18.7) 82.9 (18.7)

Emotional role Control 56.8 (32.0) 68.3 (28.0) .090 .033 .658

Training 72.5 (24.3) 88.6 (17.6)

Mental health Control 40.2 (25.2) 46.0 (18.9) .002 .707 .333

Training 73.2 (14.5) 66.8 (19.3)

Physical component scale Control 44.3 (11.5) 53.5 (8.1) .031 .367 .055

Training 58.8 (14.0) 55.4 (6.1)

Mental component scale Control 35.1 (16.8) 39.6 (19.9) .169 .322 .865

Training 44.2 (9.4) 47.9 (9.9)

Data are means (SD).

M.F. del Valle et al. / Journal of Adolescent Health 46 (2010) 352–358 357

training seems the most clinically appropriate type of exercise

program for this population group. It is also of clinical interest

to assess the efficacy of starting training interventions at the

earliest possible stages of the disease, as we did in this study.

Despite earlier concerns regarding the safety and efficacy of

youth strength training, current public health objectives now

aim to increase the number of children participating in this

exercise mode, which has the potential to increase bone

mineral density, motor performance skills, physical capacity,

and overall health status in children and adolescents [21].

Although the program was well tolerated by participants,

we did not observe significant intervention-induced strength

improvements other than in lateral row. We previously found

significant increases in all the functional and/or strength tests

that we applied here in cancer survivors of a similar age range

with myopathy induced by steroid treatment or graft-versus-

host disease [14]. The difference between the present results

and our previous findings with cancer patients [14] or those

of previous research with adult anorexic patients [11] could

be attributable to the poor physical status (very low muscle

mass) and young age of our patients, which precluded the

use of higher training loads.

Both training and control groups showed improvements in

several QOL items during the study period. This finding is in

agreement with previous research [10] and is likely due to the

favorable psychotherapy effects in both groups. However, we

did not find a significant interaction (group 3 time) effect

reflecting an actual beneficial training effect on QOL. Thien

et al [7] reported similar results in a controlled trial with older

anorexic outpatients; they assessed QOL with the Short

Form-36 questionnaire. In contrast, Szabo and Green [10]

showed that, compared with a nonexercising group, the

psychological well-being of adult hospitalized anorexic

women improved after a light resistance training program.

Psychological well-being was nevertheless assessed with

the Eating Disorder and Beck Depression Inventories.

In summary, in young anorexic patients, strength training

does not seem to add major benefits to conventional psycho-

therapy and refeeding treatments. It is nevertheless note-

worthy that this intervention was well tolerated and did not

have any deleterious effect on patients’ health, nor did it

induce significant losses in their body weight and BMI. Future

research might determine whether more intense programs are

necessary to induce significant improvements in the muscle

fitness and well-being of young anorexic outpatients.

Acknowledgments

This work was supported by grants from Universidad Eu-

ropea de Madrid (2007/UEM23 and OTRI2008/UEM14),

Fondo de Investigaciones Sanitarias (PI061183), and from

the Ministerio de Educacion y Ciencia, Spain (EX-2007-

1124), and Fundacion Blas Mendez Ponce Ayuda al Nino

Oncologico.

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