International Journal of Obesity (2004) 28, 1097–1104
& 2004 Nature Publishing Group All rights reserved 0307-0565/04 $30.00
www.nature.com/ijo
PAPER
Elderly obese women display the greatest
improvement in stair climbing performance after a
3-week body mass reduction program
A Sartorio1,2*, CL Lafortuna3, F Agosti2, M Proietti2 and NA Maffiuletti2,4
1
Division of Metabolic Diseases III, Istituto Auxologico Italiano, IRCCS, Piancavallo (VB), Italy; 2Experimental Laboratory
for Endocrinological Research, Istituto Auxologico Italiano, IRCCS, Milan, Italy; 3Institute of Molecular Bioimaging and
Physiology, CNR, Segrate (MI), Italy; and 4INSERM/ERIT-M 0207 Laboratory, University of Burgundy, Dijon, France
OBJECTIVE: To investigate whether stair climbing performance and body composition are similarly affected by a body mass
reduction (BMR) program in obese individuals of different gender, age and body mass index (BMI) level.
DESIGN: Longitudinal, clinical intervention study entailing energy-restricted diet (5023–7535 kJ/day), nutritional education,
psychological counselling and moderate physical activity (indoor cycling, outdoor walking, gymnastics routines, five sessions/
week) during a 3-week period.
SUBJECTS: A total of 466 male and 807 female subjects categorized as a function of gender, age (o vs Z50 y) and BMI (o vs
Z40 kg/m2).
MEASUREMENTS: Body mass, stair climbing time and power before and after the BMR program. Fat-free mass and fat mass
were also evaluated by bioimpedance analysis, in a representative subgroup of 160 patients, to evaluate the relation between
fat-free mass and power output.
RESULTS: Body mass, fat-free mass and fat mass significantly decreased following the BMR program (Po0.001), with male
subjects reducing body mass and fat-free mass more than and fat mass less than the female subjects. Stair climbing time
decreased (Po0.001) and therefore anaerobic power significantly increased 9.7% after the treatment. The greatest
improvement in stair climbing performance was observed in obese women aged Z50 y. Significant inverse correlations were
found between initial power or fat-free mass level and respective percent increases (R ¼ 0.35/0.37, Po0.001) and between
BMR-induced percent changes in body mass and power (R ¼ 0.13, Po0.001).
CONCLUSION: Subjects with the lowest baseline level in stair climbing performance (and probably with the lowest amount of fatfree mass), that is, obese women aged more than 50 y, obtained the largest enhancement after the 3-week BMR program, likely
improving overall functional capacities and resulting in greater independence during daily-living activities in such a population.
International Journal of Obesity (2004) 28, 1097–1104. doi:10.1038/sj.ijo.0802702
Published online 22 June 2004
Keywords: muscle power; stair climbing; BMI; sarcopenia
Introduction
Several activities of daily living (eg, stair climbing, walking,
chair rise, etc.) and brisk postural adjustments associated to
body equilibrium maintenance involve dynamic movements, where power is generated by the lower limb muscles.
*Correspondence: Dr A Sartorio, Laboratorio Sperimentale di Ricerche
Endocrinologiche (LSRE), Istituto Auxologico Italiano, IRCCS, Via Ariosto,
13, 20145 Milano, Italy.
E-mail: [email protected]
Received 25 November 2003; revised 22 February 2004; accepted 14
March 2004; published online 22 June 2004
Aging and obesity are both accompanied by a significant
decline in anaerobic muscular power,1–3 which in turn
affects life quality and maintenance of independent living
in these particular populations. Muscle power losses are
more pronounced in the aged obese (particularly in female
subjects) due to cumulative effects of sarcopenia (ie, the agerelated decline in muscle mass, strength and power4,5) and
obesity. It was indeed suggested, based on anaerobic power
estimation during stair climbing, that severely obese (body
mass index (BMI) Z40 kg/m2) women over 50 y can be
circumscribed as the most ‘disabled’ category as a consequence of obesity and aging.6
Stair climbing power in obese patients
A Sartorio et al
1098
However, it is now well recognized that sarcopenia is partly
reversible with a number of intervention strategies, including both endurance7 and strength training.8 Similarly, it
has recently been shown that maximum strength and power
of the lower limb muscles increased significantly in severely
obese male and female subjects following a body
mass reduction (BMR) program, entailing physical activity
in combination with energy-restricted diet.9 Therefore,
it appears that anaerobic muscular power can be easily
modified in both aged and obese subjects of both
sexes. However, it is still not clear whether power increases
associated to a BMR program are comparable between
obese subjects of different gender, age and BMI classes.
According to the principle of initial values recently demonstrated in nonobese women (ie, women with lower
initial power values benefited more from resistance
and impact-training than those with higher values),10 it
could be hypothesized that elderly obese women would
obtain the greatest increases in anaerobic power of the lower
limb muscles, as compared to their young and male
counterparts.
Therefore, the main aim of this paper was to compare the
changes in stair climbing performance (stair climbing time
and power) induced by a BMR program entailing diet caloric
restriction and moderate physical activity between obese
individuals of different gender, age and BMI level. A total of
1273 subjects were thus categorized according to previously
established classification,6 based on gender, age (o vs Z50 y)
and BMI level (o vs Z40 kg/m2). A secondary aim was to
study, in a representative subgroup of 160 subjects, body
composition changes between these categories of obese
individuals and their potential influence on stair climbing
performance.
disease contraindicating or interfering with the execution of
the stair climbing test, both before and after the completion
of the BMR program. All the patients gave their informed
consent to participate in the study, which was approved by
the Ethics Committee of the Istituto Auxologico Italiano. All
the procedures were conducted according to the principles
expressed in the Declaration of Helsinki.
Stair climbing test (N ¼ 1273)
Stair climbing test (SCT), which allows measuring
the maximal anaerobic power of the involved muscles,
was performed before and immediately after the completion
of the BMR program. At the moment of the first execution,
2–3 practice trials were allowed so that the subjects gained
a good control of the performing technique. SCT consists
in a modification of the test proposed by Margaria et al,11
recently applied in severely obese subjects.3,12 In brief,
subjects were invited to climb up ordinary stairs at
the highest possible speed, according to their capabilities.
The stairs consisted of 13 steps of 15.3 cm each, thus
covering a total vertical distance of 1.99 m. An experimenter
measured the time employed to cover the test with a digital
stopwatch. In line with Margaria et al11 assumptions,
anaerobic power (in W) was calculated by using the
following formula:
ðbody mass9:81vertical distanceÞ=time
where body mass, vertical distance (ie, 1.99 m) and time are
expressed in kg, m and s, respectively, and 9.81 m/s2
represents the acceleration of gravity. SCT repeatability in
obese individuals with BMI and age range similar to the
present subjects has been previously assessed in our laboratory and the coefficient of variation between measurements
has been found to be lower than 5%.13
Methods
Subjects
The study population for stair climbing test consisted of
1273 Italian subjects (466 males and 807 females) comprised
within a wide range of age (18–80 y; mean7s.d.:
45.3715.4 y) and BMI (30–66.1 kg/m2; mean7s.d.:
41.275.8 kg/m2), which were categorized according to
gender (male vs female subjects), age (younger: o50 y vs
older: Z50 y) and BMI level (lower: BMI o40 kg/m2 vs
higher: BMI Z40 kg/m2, ie, extreme or class III obesity). This
classification has recently been adopted by Sartorio et al6 to
study the influence of gender, age and obesity degree on
muscular power. A subgroup of 160 patients (80 male and 80
female subjects) of comparable age (mean7s.d.:
47.1716.1 y) and BMI (mean7s.d.: 41.175.3 kg/m2) was
considered for the additional assessment of body composition. All the subjects were followed at the 3rd Division of
Metabolic Diseases (Istituto Auxologico Italiano, Piancavallo, Italy), where they had been admitted for a BMR program
(see below). None of the individuals had signs or symptoms
referable to overt cardiovascular, respiratory or orthopaedic
International Journal of Obesity
Body composition (N ¼ 160)
Fat-free mass and fat mass were assessed by bioelectric
impedance analysis, performed in the early morning after an
overnight fast, according to a conventional standard technique.14 Whole-body resistance to an applied current (at 1, 5,
10, 50 and 100 kHz, 0.8 mA) was measured with a tetrapolar
device (Human IM, Dietosystem, Milan, Italy). The electrodes were placed on the right wrist and ankle of the subjects
while lying comfortably supine in a bed with the limbs
abducted from the body. Fat-free mass was calculated with
the fat-specific equations derived by Gray et al15 Fat mass was
derived as the difference between total body mass and fatfree mass.
BMR program
The BMR program combined an energy-restricted diet,
nutritional education, psychological counselling and moderate physical activity during a 3-week period.
Stair climbing power in obese patients
A Sartorio et al
1099
Caloric intake was restricted by means of a diet (5023–
7535 kJ/day, ie, 1200–1800 kcal/day) containing 21% proteins, 53% carbohydrates and 26% lipids. The amount of
energy to be given with diet was calculated by subtracting
approximately 2093 kJ (500 kcal)16 from the measurement of
basal energy expenditure, as assessed by indirect calorimetry
(Vmax 29; SensorMedics Corporation, Yorba Linda, CA, USA)
for a total duration of 20 min, while the subjects rested in
bed. The estimated H2O content of the food was 1000 ml/day
and the estimated salt content was 1560 mg/day of Na þ ,
3600 mg/day of K þ and 900 mg/day of Ca2 þ . A fluid intake
of at least 2000 ml/day was encouraged. Dietary compliance
was evaluated every day by a dietician. Nutritional education
consisted of lectures, demonstrations and group discussions
with and without a supervisor, which took place every day
throughout the experimental period. Psychological counselling sessions were conducted by clinical psychologists 2–3
times/week and were based on individual or cognitivebehavioral strategies, for example, stimulus control procedures, problem solving training, stress management skills,
development of healthy eating habits, assertiveness training,
facilitation of social supports, cognitive restructuring of
negative maladaptive thoughts and relapse prevention
training.
Physical activity consisted of five training sessions/week
including indoor light jogging, dynamic exercises of the
upper and lower limbs (standing and floor gymnastics
routines focalized on muscle strength-power development
by using body mass as movement resistance) at moderate
intensity under the guide of a therapist (B1 h), and either
20–30 min aerobic exercise on an ergocycle at B60 W
(Technogym, Gambettola, Italy), or 3–4 km outdoor walking
on a predetermined track, according to individual capabilities and clinical status. Heart rate was monitored during
typical training sessions in the majority of the experimental
subjects by means of a telemetric system (Polar, Kempele,
Finland) and, as a general observation, it was comprised
between 110 and 160 beats/min, that is, between 55 and 75%
of the individual maximal heart rate estimated as 220age
(y).
of SCT power or time or fat-free mass and respective percent
changes. In each case, the level of significance was
established at Pr0.05. Statistical analyses were performed
using Statistica software (StatSoft, Tulsa, OK, USA).
Results
The present BMR program resulted in significant body mass
(and BMI) reductions for the entire subject group (Po0.001,
Table 1). A significant main effect was found for gender, age
and BMI level (Table 2), and body mass percent decreases
were significantly higher in male (4.8%) vs female subjects
(3.9%), young (4.5%) vs old (4.2%) and in subjects with
lower (4.4%) vs higher BMI (4.2%). Moreover, a significant gender BMI interaction (Po0.001) was observed, with
males BMI o40 kg/m2 and female subjects BMI o40 kg/m2
obtaining the largest (5.1%) and the smallest (3.8%) body
mass reduction, respectively.
In the subgroup of 160 individuals, body mass reductions
were almost identical to those obtained with the whole
group (Table 3). Both fat-free mass and fat mass significantly
decreased after the BMR program (Po0.001), with male
subjects demonstrating significant larger reductions in fatfree mass (Figure 1a, Po0.001) but smaller changes in fat
mass compared to female subjects (Figure 1b, Po0.01).
SCT time significantly decreased following the BMR
program (Po0.001) and, as a consequence, SCT power
significantly increased (Po0.001, Table 1). A significant
gender age BMI interaction was found for SCT time
Table 1 Body mass, SCT time and power before and after the BMR program
and respective absolute and percent changes in the whole study population
(N ¼ 1273)
Pre-BMR
Absolute
changes
Percent
changes
Body mass (kg)a 110.6719.4 105.8718.4b 4.7272.23 4.2271.68
5.0072.60 4.3772.03b 0.6371.32 9.42716.36
SCT time (s)a
SCT power (W)a
5037191 534.37191.0b 31.0790.1 9.73724.00
a
Statistical procedures
Wilcoxon test for nonparametric values were performed to
compare means obtained before and after the BMR program
for dependent variables (body mass, BMI, SCT time and
power for N ¼ 1273 and body mass, fat-free and fat mass for
N ¼ 160). The associated percent changes, calculated as:
((prepost)/pre) 100, were analyzed for significant differences using a three-way analysis of variance (gender age BMI level). The F-ratios were considered
significant at Po0.05. A LSD post hoc test was conducted if
significant main effects or interactions were present.
Spearman rank order correlations were used to assess the
significance of relations between BMR-induced percent
changes in power and body mass and between initial values
Post-BMR
Mean values7s.d. bSignificantly different than prevalues (Po0.001).
Table 2 ANOVA results associated to body mass, SCT time and power
percent changes
Gender effect
Body mass
a
F ¼ 93.91
M4F
b
Age effect
c
BMI effect
d
Interaction
F ¼ 8.31
Young 4old
F ¼ 4.11
Low4high
F ¼ 13.44b
Gender BMI
SCT timea
F
F
F
F ¼ 3.84d
Gender age BMI
SCT powera
F ¼ 7.94c
MoF
F
F
F ¼ 5.97d
Gender age
a
Mean values7s.d. bSignificant main effect or interaction (Po0.001).
Significant main effect or interaction (Po0.01). dSignificant main effect or
interaction (Po0.05). Note: N ¼ 1273.
c
International Journal of Obesity
Stair climbing power in obese patients
A Sartorio et al
1100
Table 3
Body mass, fat-free and fat mass before and after the BMR program and respective absolute and percent changes in the subgroup of 160 subjects
Body mass (kg)a
Fat-free mass (kg)a
Fat mass (%)a
Pre-BMR
Post-BMR
Absolute changes
Percent changes
111.8719.9
60.8714.6
45.877.4
107.5719.0b
59.1713.7b
45.177.3b
4.3771.96
1.7272.17
0.6971.69
3.8871.46c
2.5573.47c
1.4273.82d,e
a
Mean values7s.d. bSignificantly lower than prevalues (Po0.001). cSignificant main gender effect (Po0.001). dSignificant main gender effect (Po0.01). eSignificant
main age effect (Po0.01). Note: significant main effects are associated to three-way ANOVA on percent changes.
elderly women compared to young men and women
(Po0.01) and to elderly men (Po0.001, Figure 2b).
Percent changes in SCT time and power obtained after the
treatment were also plotted as a function of initial respective
values for all the experimental subjects, to study whether the
principle of initial values is also valid for obese populations.10 A significant inverse correlation was found for both
SCT time (R ¼ 0.433, Po0.001) and power (Po0.001,
Figure 3a), indicating that obese patients with high SCT
time and low SCT power at baseline benefited more from the
BMR program than faster and more powerful subjects. The
same result was then obtained when considering initial fatfree mass values (Figure 3b), therefore suggesting that those
subjects with higher fat-free mass (and consequently higher
power) at baseline obtained the greatest fat-free mass losses
(and thus the lowest power enhancement) after the treatment, according to the principle of initial values. These
assumptions were then confirmed by the significant (inverse) correlation that was found between percent changes
in body mass and SCT power (N ¼ 1273, R ¼ 0.127,
Po0.001).
Discussion
Figure 1 Percent changes in fat-free mass (a) and fat mass (b) after the BMR
program as a function of gender. Vertical bars represent s.e.m. and N ¼ 160.
LSD post hoc tests showed the following differences: **: significantly different
than males (Po0.01); ***: significantly different than males (Po0.001).
changes (Table 2) and female subjects aged Z50 y with BMI
Z40 kg/m2 obtained the largest improvements (Figure 2a).
Muscle power increased more in female ( þ 11.2%) compared
to male subjects ( þ 7.3%, Po0.01), and the same was true for
International Journal of Obesity
The present investigation demonstrated that a 4.2% body
mass reduction, obtained after an integrated BMR program
lasting 3 weeks was accompanied by enhanced stair climbing
performance, that is, shorter time of execution and higher
power output, in 1273 obese men and women aged 18–80 y.
The main finding of this study is that greater BMR-induced
power increases were observed in those subjects displaying
lower initial values, that is, elderly obese women, even
though body mass losses in female subjects were significantly smaller as compared to their male counterparts.
Maximal muscle power, which depends on the product of
muscular force and velocity of shortening, declines more
precipitously than strength with advancing age.17,18 Reduced muscle power (ie, reduced muscle strength and/or
movement velocity) is associated with a reduction in the
ability to perform activities of daily living in older individuals, more particularly in obese subjects. Sartorio et al6,12
have indeed provided experimental evidence that aged obese
of both genders produce lower stair climbing power as
compared to their younger counterparts. However, although
a number of studies have shown that muscle power can be
Stair climbing power in obese patients
A Sartorio et al
1101
Figure 2 Percent changes in SCT time (a) and power (b) after the BMR program as a function of gender, age (o vs Z50 y) and BMI level (o vs Z40 kg/m2).
Vertical bars represent s.e.m. and N ¼ 1273. LSD post hoc tests showed the following differences: *: significantly lower than female subjects Z50 y BMI Z40
(Po0.05); **: significantly lower than female subjects Z50 y BMI Z40 (Po0.01); ww: significantly lower than female subjects Z50 y (Po0.01); www: significantly lower
than female subjects Z50 y (Po0.001).
improved in nonobese older individuals using standardized
physical training protocols (eg, resistance training19–22), it is
unclear whether this is also possible in the case of the aged
obese. The present study clearly demonstrated that elderly
obese of both genders and with different degrees of obesity
positively benefited from the BMR program, since stair
climbing time and power were both enhanced after the 3week treatment, especially in female subjects. This is
noteworthy, since power and strength increases in elderly
seem to be directly in relation with improvements of some
functional capacities, such as stepping up and rising from
the kneeling position on the floor19 and also gait velocity.23
Unfortunately, walking speed changes were not measured in
this study, but, since power was quantified during a typical
activity of daily living, we conclude that overall functional
capacity of elderly obese is enhanced by a 3-week BMR
program, entailing diet caloric restriction and physical
activity. Stair climbing power increases obtained here are
consistent with those previously reported for nonobese older
men and women after physical training (for a review, see Pu
and Nelson24), but a systematic comparison of the plasticity
of muscle power to training between old obese and nonobese
is necessary.
The extremely obese (ie, BMI higher than 40 kg/m2)
women over 50 y tested in the present study have been
previously identified as the most ‘disabled’ category on
International Journal of Obesity
Stair climbing power in obese patients
A Sartorio et al
1102
Figure 3 Correlations between initial levels of SCT power and respective
BMR-induced percent changes in the whole study population (a, N ¼ 1273)
and between baseline fat-free mass and percent changes in the subgroup of
160 subjects (b). R- and P-values associated to Spearman rank order
correlations are shown.
account of the low power output during stair climbing.6
However, BMR-induced stair climbing time reductions were
higher in this group and power increased more in elderly
female subjects with respect to the other subjects, therefore
indicating that the adaptive capacity of stair climbing
performance was superior in individuals with low initial
values (see also below). Previous research demonstrated
similar improvements in whole muscle characteristics
among elderly men and women25,26 and among young and
old nonobese subjects27,28 following resistance training
protocols. However, little is known on the differential
adaptability of elderly male vs female or young vs old obese
subject and for the first time, the present study demonstrated
that older obese women increased power more than their
male and young counterparts. These findings are unique and
require further investigation, in order to understand the
basic mechanisms modulating muscle power adaptability
with gender, aging and physical activity.
International Journal of Obesity
In our study, male subjects generally displayed larger body
mass reductions than female subjects at the completion of
the BMR program, in line with earlier studies performed with
smaller populations.12,29 An intriguing finding comes from
the inverse correlation between BMR-induced changes in
body mass and SCT power, that is to say, large body mass
losses in obese males were associated with small increases of
stair climbing power and vice versa for female subjects. Even
though fat mass and fat-free mass were measured only in a
representative subgroup of 160 subjects, it is concluded that
the present BMR program resulted in different body
composition changes between genders, where women
mainly reduced the proportion of fat mass and only to a
lesser extent fat-free mass, while the opposite outcome was
observed in males. Assuming that neural adaptations (ie,
changes within the nervous system30) explaining the
majority of the present BMR-induced power improvements
were comparable between male and female subjects,8 sizeable reductions in fat-free mass in the former subjects
inevitably minimized the magnitude of power increases. It
is important to note that, in obese children, such an
alteration during a 3-week BMR program similar to that
adopted here has been recognized as a major factor for later
regain in body mass.31 However, the same authors later
demonstrated that fat-free reductions could be minimized by
standardized resistance training program combined with
caloric restriction,32 also in line with the recent review of
Donnelly et al33 (see also below).
The principle of initial values states that subjects with
lower initial values of a physiological variable will exhibit
the greatest improvement in response to specific exercise
training. Winters-Stone and Snow10 have recently shown
that initial levels of bone mass density, stability, strength and
power were significantly correlated with training-induced
percent changes in 31 premenopausal nonobese women,
thus initial values predicted the response of the musculoskeletal system to training. In the current investigation, a
significant inverse relation was found between baseline SCT
time or power and the associated BMR-induced changes, that
is, obese subjects with lower initial levels (elderly obese
females) benefited more from the treatment than those with
higher values. Therefore, the present findings confirm that
the principle of initial values is also applicable in a large
population of obese subjects of different gender, age and BMI
level. The data in Figure 3a enable the estimation of the
expected increase in SCT power that an obese individual
would obtain as a result of a BMR program entailing diet
caloric restriction and moderate physical activity, by including baseline SCT power in the following equation:
Percent D SCT power ¼ ð0:05baseline SCT powerÞ
þ 34:44
Based on these theoretical calculations, subjects with baseline SCT power equal to or higher than 700 W would obtain
no changes or even reductions of the muscle power
following the present BMR program. This suggests that for
Stair climbing power in obese patients
A Sartorio et al
1103
obese subjects with high baseline power levels (mainly men
aged o50 y), 3 weeks of physical activity performed at
moderate intensity with five sessions per week may have
been too light and not sufficient enough to increase stair
climbing power. Therefore, it is recommended that the
physical training considered in the present study must be
implemented, at least for the most fit obese individuals, with
specific exercises for the development of power and/or
strength of the lower limb muscles, in order to maintain
fat-free mass during BMR.
In conclusion, we have completed a 3-week BMR program
in a large population of obese individuals, and studied the
effects of gender, age and BMI level on the muscular power
estimated during a simple functional test. Body mass
reductions of B4% were accompanied by a substantial
enhancement (B9%) of the stair climbing performance
(stair climbing time and power) and these changes were
related together (ie, low power increases were associated to
high body mass reductions, eg, in male subjects). In the same
way, a significant inverse correlation was found between
initial values at the stair climbing test or fat-free mass and
respective percent changes. These findings indicate that
subjects with the lowest baseline muscle power (and
probably with the lowest amount of muscle mass), namely
obese women aged Z50 y, obtained the largest power
enhancement after the treatment, therefore confirming that
the principle of initial values is also valid for obese
individuals. These positive effects could allow elderly obese
female subjects to perform common daily activities better
(previously precluded) and possibly to maintain better
compliance to regular exercise activity at home. Further
studies are requested to ascertain whether the short-term
effects observed here are similarly maintained in obese
subjects of different gender, age and BMI during long-term
follow-up.
Acknowledgements
This study is partially supported by Progetto di Ricerca
Corrente, Istituto Auxologico Italiano, IRCCS, Milan, Italy.
The technical assistance of Mr S Ottolini was greatly
appreciated. We are indebted to Drs G Silvestri, A Tibaldi
and M Resnik and to Ms F Pera of the 3rd Division of
Metabolic Diseases for their qualified assistance during the
execution of the test.
References
1 De Vito G, Bernardi M, Forte R, Pulejo C, Macaluso A, Figura F.
Determinants of maximal instantaneous muscle power in women
aged 50–75 years. Eur J Appl Physiol 1998; 78: 59–64.
2 Martin JC, Farrar RP, Wagner BM, Spirduso WW. Maximal power
across the lifespan. J Gerontol A Biol Sci Med Sci 2000; 55: M311–
M316.
3 Lafortuna CL, Fumagalli E, Vangeli V, Sartorio A. Lower limb
alactic anaerobic power output assessed with different techniques
in morbid obesity. J Endocrinol Invest 2002; 25: 134–141.
4 Dutta C, Hadley EC, Lexell J. Sarcopenia and physical performance in old age: an overview. Muscle Nerve 1997; (Suppl 5):
S5–S9.
5 Vandervoort AA. Aging of the human neuromuscular system.
Muscle Nerve 2002; 25: 17–25.
6 Sartorio A, Proietti M, Marinone PG, Agosti F, Adorni F, Lafortuna
CL. Influence of gender, age and BMI on lower limb muscular
power output in a large population of obese men and women. Int
J Obes Relat Metab Disord 2004; 28: 91–98.
7 Coggan AR, Spina RJ, King DS, Rogers MA, Brown M, Nemeth PM,
Holloszy JO. Skeletal muscle adaptations to endurance training in
60- to 70-yr-old men and women. J Appl Physiol 1992; 72: 1780–
1786.
8 Häkkinen K, Kallinen M, Izquierdo M, Jokelainen K, Lassila H,
Mälkiä E, Kraemer WJ, Newton RU, Alen M. Changes in agonistantagonist EMG, muscle CSA, and force during strength training
in middle-aged and older people. J Appl Physiol 1998; 84: 1341–
1349.
9 Sartorio A, Lafortuna CL, Massarini M, Galvani C. Effects of
different training protocols on exercise performance during a
short-term body weight reduction programme in severely obese
patients. Eating Weight Disord 2003; 8: 36–43.
10 Winters-Stone KM, Snow CM. Musculoskeletal response to
exercise is greatest in women with low initial values. Med Sci
Sports Exerc 2003; 35: 1691–1696.
11 Margaria R, Aghemo P, Rovelli E. Measurement of muscular
power (anaerobic) in man. J Appl Physiol 1966; 21: 1662–1664.
12 Sartorio A, Lafortuna CL, Conte G, Faglia G, Narici MV. Changes
in motor control and performance after a short term body mass
reduction program in obese subjects. J Endocrinol Invest 2001; 24:
393–398.
13 Sartorio A, Fontana P, Trecate L, Lafortuna CL. Short-term
changes of fatigability and muscle performance in severe obese
patients after an integrated body mass reduction program. Diab
Nutr Metab 2003; 16: 88–93.
14 Lukaski HC, Bolonchuk WW, Hall CB, Siders WA. Validation of
tetrapolar bioelectrical measurements to assess human body
composition. J Appl Physiol 1986; 60: 1327–1332.
15 Gray DS, Bray GA, Gemayel N, Kaplan K. Effects of obesity on
bioelectrical impedance. Am J Clin Nutr 1989; 50: 255–260.
16 Bray GA. Contemporary Diagnosis and Management of Obesity.
Handbooks in Health Care Co Newton: Pennsylvania; 1998.
17 Skelton DA, Greig CA, Davies JM, Young A. Strength, power and
related functional ability of healthy people aged 65–89 years. Age
Ageing 1994; 23: 371–377.
18 Young A, Skelton DA. Applied physiology of strength and power
in old age. Int J Sports Med 1994; 15: 149–151.
19 Skelton DA, Young A, Greig CA, Malbut KE. Effects of resistance
training on strength, power, and selected functional abilities of
women aged 75 and older. J Am Geriatric Soc 1995; 43: 1081–1087.
20 Joszi AC, Campbell WW, Joseph L, Davey SL, Evans WJ. Changes
in power with resistance training in older and younger men and
women. J Geront A Biol Sci Med Sci 1999; 54: M591–M596.
21 Fielding RA, LeBrasseur NK, Cuoco A, Bean J, Mizer J, Fiatarone
Singh MA. High-velocity resistance training increases skeletal
muscle peak power in older women. J Am Geriatr Soc 2002; 50:
655–662.
22 Izquierdo M, Häkkinen K, Ibañez J, Garrues M, Antòn A, Zúñiga
A, Larrión JL, Gorostiaga EM. Effects of strength training on
muscle power and serum hormones in middle-aged and older
men. J Appl Physiol 2001; 90: 1497–1507.
23 Judge JO, Underwood M, Gennosa T. Exercise to improve gait
velocity in older persons. Arch Phys Med Rehabil 1993; 74:
400–406.
24 Pu CT, Nelson ME. Aging, function and exercise. In: Frontera WR,
Dawson DM, Slovik DM (eds) Exercise in Rehabilitation Medicine.
Human Kinetics: Champaign, IL; 1999.
25 Lexell J, Downham DY, Larsson Y, Bruhn E, Morsing B. Heavyresistance training in older Scandinavian men and women: short-
International Journal of Obesity
Stair climbing power in obese patients
A Sartorio et al
1104
26
27
28
29
and long-term effects on arm and leg muscles. Scand J Med Sci
Sports 1995; 5: 329–341.
Brown A, McCartney N, Sale DG. Positive adaptations to weightlifting in the elderly. J Appl Physiol 1990; 69: 1725–1733.
Cartee GD. Aging skeletal muscle: response to exercise. Exerc Sport
Sci Rev 1994; 22: 91–120.
Newton RU, Häkkinen K, Häkkinen A, McCormick M, Volek J,
Kraemer WJ. Mixed-methods resistance training increases power
and strength of young and older men. Med Sci Sports Exerc 2002;
34: 1367–1375.
Sartorio A, Narici MV, Fumagalli E, Faglia G, Lafortuna CL.
Aerobic and anaerobic performance before and after a short-term
body mass reduction program in obese subjects. Diab Nutr Metab
2001; 14: 51–57.
International Journal of Obesity
30 Duchateau J, Enoka RM. Neural adaptations with chronic activity
patterns in able-bodied humans. Am J Phys Med Rehabil 2002; 81:
S17–S27.
31 Schwingshandl J, Borkenstein M. Changes in lean body mass in
obese children during a weight reduction program: effect on
short term and long term outcome. Int J Obes Relat Metab Disord
1995; 19: 752–755.
32 Schwingshandl J, Sudi K, Eibl B, Wallner S, Borkenstein M. Effect
of an individualised training programme during weight reduction on body composition: a randomised trial. Arch Dis Child
1999; 81: 426–428.
33 Donnelly JE, Jakicic JM, Pronk N, Smith BK, Kirk EP, Jacobsen DJ,
Washburn R. Is resistance training effective for weight management? Evidence-Based Prev Med 2003; 1: 21–29.