TITLE:
Physical exercise intensity prescription to improve health and fitness in overweight and obese subjects: A review of the literature
AUTHORS:
Gian Pietro Emerenziani, Silvia Migliaccio, Maria Chiara Gallotta, Andrea Lenzi, Carlo Baldari, Laura Guidetti
KEYWORDS:
Obesity; Overweight; Exercise Intensity Prescription; Gas Exchange Thresholds; Health
JOURNAL NAME:
Health,
Vol.5 No.6B,
June
27,
2013
ABSTRACT: Obesity is one of the greatest public health challenges of
the 21st century. Overweight and obesity drastically increase a person’s risk
of developing chronic non-communicable diseases (NCDs), including
cardiovascular disease, cancer and diabetes. Furthermore, obesity is already
responsible for 2% -8% of health costs and 10% -13% of deaths in several
industrialized countries. Lifestyle modifications involving changes in exercise,
diet and psychological support are effective in reducing the incidence of
overweight. Moreover, positive effects of physical activity (PA) for weight
loss and prevention of weight regain are well documented. It was recognized
that health benefits regarding both psychological and physiological aspects,
such as improving cardiorespiratory and muscular fitness and/or decreasing
depression symptoms, can be obtained from numerous activities. Public health
institutions (American College of Sports Medicine, World Health Organization)
provide recommendations for PA (volume, frequency, intensity and type of exercise)
to achieve positive effects, at all ages and for many diseases and disorders
situations. Although exercise under guidelines can be safely performed by
obese subjects, several questions still need to be fully answered. In facts,
the exercise program should be tailored according to an individual’s habitual
physical activity, physical function, health status, exercise responses, and
stated goals. Thus, this review analyzes the intensity of PA parameters. In the
last years, research has been focused on the
individualization of the right intensity in which different types of
subjects’ condition must undergo to achieve the health goals. Aerobic exercise
has been commonly used to reach weight loss goal. Prescription of aerobic exercise
in clinical practice is frequently based on the percentage of maximum heart
rate (%HRmax), heart rate reserve (%HRreserve), rating of
perceived exertion (RPE), maximal oxygen consumption (%VO2max) and
for unhealthy subjects, peak oxygen consumption (%VO2peak). It has
been shown that unhealthy
subjects, such as individuals affected by diabetes, obesity and
cardiovascular diseases have a reduced maximal aerobic exercise capacity. For
instance, using the formula based on percentage of HRmax or VO2max,
it could be prescribed heavy exercises, which would result not appropriated
and fully functional for the specific individual goal. To avoid this problem,
another approach to individualize aerobic exercise could be to consider the
gas exchange parameters such us aerobic gas exchange threshold (AerTGE).
AerTGE corresponds to the first increase in blood lactate during
incremental exercise. This review offers an overview of the different
methods to assess exercise intensity, considering the different subjects health
characteristics, in order to choose the right methods to achieve the health
goals in obese and overweight subjects.