Rev Bras Fisiol Exerc 2020;19(3):218-23
ORIGINAL
ARTICLE
Effect
of strength training on the agonist-antagonist sequence to improve functional
fitness in older women
Efeito do treinamento
de força na sequência agonista-antagonista na melhora da aptidão funcional em
mulheres idosas
Ana Paula Sena
Vasconcelos1, Diogo Cardozo1
1Faculdade Metodista Granbery - FAMIDADE, Juiz de Fora, Minas Gerais, MG,
Brasil
Receipt
on: March 27; 2020; Accepted on: June 2, 2020.
Corresponding author: Diogo Cardozo,
Faculdade Metodista Granbery - FAMIDADE, Rua Batista
de Oliveira, 1145 Granbery 36010-530 Juiz de Fora MG,
Brazil.
Ana Paula Sena
Vasconcelos: a.paula.sena@uol.com.br
Diogo Cardozo:
dcardozoef@gmail.com
Abstract
Introduction: Strength training (ST) is effective to improve functional fitness (FF)
in older people. However, the literature is scarce in relation to some ST
methods. Objective: To verify the effect of an agonist-antagonist
circuit training model (AACT) on FF in older women. Methods: Thirteen
older women (68.6 ± 6.1 years, 66.4 ± kg, 1.57 ± 0.007 meters) were recruited
to participate in this research. These women were submitted to the Senior
Fitness Test to evaluate FF and measurements of body weight, height and calf
circumference to check body composition. The training protocol was based on
AACT model with exercises performed following this sequence: knee extension,
knee flexion, abductor and adductor machine, bench press, rowing machine,
triceps and biceps curls during eight weeks. The
participants performed three sets of 8 to 10 repetitions with 30-second
intervals in the circuit training model. Results: After eight weeks of
AACT training, FF improved significantly (p ≤ 0.05). However, there were
no differences in body composition (p ≥ 0.05). Conclusion: The
training organized in an AACT model improves FF and may be used to maintain an
active lifestyle and improve the quality of life in this population.
Keywords: older people; strength training; functional capacity.
Resumo
Introdução: O treinamento de
força (TF) é efetivo para aumentar a aptidão funcional (AF) em idosos.
Entretanto, a literatura é escassa em relação a alguns métodos de TF. Objetivo:
Verificar o efeito de um modelo de treinamento agonista-antagonista realizado
em circuito (AAC) na AF em mulheres idosas. Métodos: Foram recrutadas 13
mulheres idosas (68,6 ± 6,1 anos, 66,4 ± kg, 1,57 ± 0,007 metros) para
participar desta pesquisa. Todas foram submetidas ao Sênior Fitness Test para
avaliar a AF e medidas de peso, estatura e circunferência de panturrilha para
medir a composição corporal. O protocolo de treinamento foi em um modelo AAC
com exercícios realizados na sequência: extensão de joelhos, flexão de joelhos,
cadeira abdutora, cadeira adutora, supino reto, remada articulada, rosca
tríceps e rosca bíceps durante oito semanas. Todas realizaram entre 8 e 10
repetições, intervalo de 30 segundos e três séries no circuito. Resultados:
Após oito semanas de treinamento AAC, a AF melhorou significativamente (p ≤
0,05). Porém, não foram observadas diferenças para a composição corporal (p ≥
0,05). Conclusão: O treinamento organizado em um modelo AAC promove
melhora da AF e pode ser utilizado para manutenção de uma vida ativa e melhora
da qualidade de vida nessa população.
Palavras-chave: idoso; treinamento de
força; capacidade funcional.
Strength training (ST) is considered
as an effective training method in order to increase the strength, muscle mass
and functional fitness gains in older people [1-4]. Recognized health
organizations such as the American College of Sports Medicine (ACSM) [5] and
the American Heart Association (AHA) [6] recommend ST as a relevant support for
the treatment of many different pathologies. However, the various possibilities
of training methods and systems that can be performed in ST sessions [7] should
be considered.
Concerning the training method, the ACSM
indicates in the guidelines the training organized in a circuit format
alternating upper and lower limb exercises [1]. This type of training helps to
improve cardiorespiratory capacity and promote strength gains and functional
fitness in older people [3,4,8,9].
Cardozo et al. [4] have recently
demonstrated that the ST performed in a circuit training with different
exercise sequences increased strength, muscle mass and improved functional
fitness in older women. However, the authors emphasized that to achieve muscle
strength gains the exercise sequence must respect the principle of priority,
considering that the exercises allocated at the beginning of the training
sessions showed greater gains in muscle strength.
Another way of organizing the exercise
sequence may be performed using the agonist-antagonist model, which consists of
after performing an exercise for the agonist's muscle, an exercise is performed
for the antagonist’s muscle [7,10]. This training method provides a higher
volume of muscle work comparing to the traditional training method [11] and greater
training efficiency because it reduced overall training time to perform the
exercise sessions [12]. Therefore, it can be implemented as a plan to optimize
training results spending less time. However, there is not much research
approaching circuit training organized in an agonist-antagonist model applied
to older people. Thus, new studies that investigate the effects of different
training methods are required to contribute to providing more information for
the prescription of exercises in this population. For this reason, the
objective of this study was to verify the effect of an agonist-antagonist
training model in a circuit format focusing on functional fitness in older
women.
Sample
Thirteen older women (68.6 ± 6.1 years,
66.4 ± 12.2 kg, 1.57 ± 0.07 m) that took part of a physical activity program to
older people were recruited to participate in this research.
Inclusion criteria adopted for
participation in this study were: a) older women with at least six months in ST
practice with training frequency twice a week; b) do not present any
cardiological and/or motor contraindications that would negatively influence
the training routines and c) any type of exercise different from those
prescribed in the ST protocols was allowed to prevent any type of interference.
This study was approved by Research Ethics Committee, under the number 847.611.
Assessment
of functional fitness and body composition
The functional tests applied were
based on the Senior Fitness Test [13,14]:
a)
30s Chair Stand - Number of times the subject gets up from the chair for a
period of 30 seconds. This test measures the dynamic strength of the lower
limbs;
b)
Arm Curl - Number of elbow flexions in which the subject performs for a period
of 30 seconds. This test measures the dynamic strength of the upper limbs;
c)
Chair Sit and Reach - Number of centimeters reached with one leg extended. This
test measures the flexibility of the lower limbs;
d)
8-Foot Up-and-Go - Number of seconds required to get up from the chair, walk
2.44 meters and return to the initial position. This test measures muscle
power, agility and balance.
For body composition, data such as body
weight, height, body mass index (BMI) and calf circumference were collected.
Specifically, the calf circumference measure was used in the present study to
indicate the muscle mass of the participants [15]. All tests used in the
present study were validated and presented an adequate correlation with more
sophisticated assessment methods [14,15].
Training
protocol
After the initial evaluations, the
volunteers were directed to eight weeks of ST. The exercises were organized in
an agonist-antagonist model with the exercises following the sequence: knee
extension, knee flexion, abductor and adductor machine, bench press, rowing
machine, triceps and biceps curls.
The training was performed in a
circuit format and three sets of 30-second interval were applied. The number of
repetitions was eight to ten and the loads were subjectively adjusted (scores
between 7 and 8 as a reference) according to the OMNI-RES effort perception
scale. When any participant was comfortably able to do three sets of ten
repetitions comfortably, the weight was raised to maintain the number of
repetitions and the training stimulus [3,4]. During the training sessions, all
volunteers were monitored by a Physical Education professional with experience
in ST.
Statistical
analysis
To verify the normality of the sample,
the Shapiro Wilk test and homoscedasticity (Bartlett's criterion) were applied.
For the analysis of functional fitness and body composition, the paired t-test
was applied to investigate the possible differences between the pre and
post-training periods. Data are represented by the mean and standard deviation.
A significance level of p ≤ 0.05 was adopted. The analyzes were performed
using the SPSS 20.0 software.
Table I shows the results of functional
fitness and body composition in the pre- and post-training periods. After eight
weeks of ST performed in circuit format, significant improvements were observed
in the functional tests p ≤ 0.05. However, there were no differences in
body composition after the training period p ≥ 0.05.
Table
I - Values in the mean and standard deviation of
functional fitness and body composition
*Indicates
significant difference in relation to the pre-training period; 1 = Number of
repetitions; 2 = values in centimeters; 3 = Values in seconds; **Body mass
index
The findings of this study demonstrated
that eight weeks of ST performed in an agonist-antagonist circuit model
improves functional fitness in older women. These results are important and
emphasize relevance of prescription of ST as a measure to improve/maintain
functionality in this population.
It is well known that human aging is a
period marked by a reduction in physiological functions that can impact the
performance of activities of daily living.
According to Rikli
and Jones [14], functional capacity, which is defined as the physiological
capacity to perform independently activities of daily living, in a safe way and
without fatigue, can decrease around 40% between 60 and 90 years of age [14].
These negative adaptations could be explained by the reduction in levels of
strength and muscle mass over the years. It is estimated a reduction in muscle
mass of approximately 1% to 2% after 50 years of age and another 40% between 50
and 80 years of age [16]. Related to the levels of muscle strength, these
reductions can reach values of 28.5% (over twelve years of follow-up) in muscle
groups of lower limbs, which may lead to a reduction in the level of physical
activity, physical dependence and the acquisition of diseases chronic
degenerative disorders [14,17-19]. On the other hand, when elderly people are
submitted to an ST program, the levels of strength and muscle mass can
increase, keeping them fit to manage an active and independent life [4,19].
Literature data report surprising increases of 174% in muscle strength gains in
nonagenarian people, demonstrating that despite their advanced old age it is
possible to obtain these benefits [20].
It was observed an improvement in all
functional tests evaluated in the present study. Thus, the increase in the
number of repetitions in the 30s chair stand and arm curl tests can be
attributed to the increase in the dynamic muscular strength of the lower and
upper limbs, respectively. The Chair Sit and Reach test was improved due to
gains in flexibility in the lower limbs, besides the 8-Foot Up-and-Go test that
measures the time spent getting up from the chair, walk a few meters and
returning to the starting position can be related to the increasing levels of
muscle power, agility and balance. These results corroborate other studies
developed, demonstrating that the ST performed in a circuit is effective to
improve functional fitness in people older [3,4,20,21]. However, this study approached
an agonist-antagonist training model different from the traditional training
models adopted in other studies. Therefore, our findings reinforce the
agonist-antagonist training model offering another training option to be
prescribed in training programs for older individuals.
Regarding body composition, our results
showed a tendency to reduce body weight and BMI. However, these values were not
sufficient to induce statistically significant
differences.
Some studies attribute the measure of
calf circumference as an indicator of muscle mass in older people [15]. In this
study, this measurement increased but it was not statistically significant in
relation to initial values. Perhaps this outcome may be attributed to the fact
that a specific exercise for the gastrocnemius muscle was not used in this
study. Regardless of this fact, the training protocol used here promotes
improvement in functional fitness and can therefore be adopted in ST programs
for the elderly.
According to the results of this study,
training organized in an agonist-antagonist circuit model improves functional
fitness and may be used to maintain an active lifestyle and improve quality of
life in this population.