**1. Introduction**

Cardiovascular disease (CVD) is the number one cause of death worldwide [1]. It includes diseases of the heart, blood vessels supplying the heart, brain, and other organs [2] and includes diseases such as angina, myocardial infarction (MI) (heart attack), cerebrovascular attacks (stroke), heart failure, cardiomyopathy, carditis, abnormal heart rhythms, congenital heart disease, rheumatic heart disease, valvular heart disease, hypertensive heart disease, aortic aneurysms, peripheral artery disease, thromboembolic disease and venous thrombosis [3].

The underlying cause of CVD varies depending on the disease and may be caused by a variety of factors [4]. These risk factors for developing CVD are traditionally divided into primary and secondary risk factors with primary risk factors being those risk factors that have conclusively shown to have a strong association with CVD. In this regard, smoking, hypertension, dyslipidemia and physical inactivity, are the four traditional primary risk factors [5]. On the other hand, secondary risk factors include diabetes mellitus, obesity, diet, psychological factors, age, hereditary/family history, gender, ethnicity/race, and personal (previous) history [5]. Thankfully, CVD risk factors can be classified into modifiable and non-modifiable risk factors. Of particular importance to healthcare practitioners

are the modifiable CVD risk factors, since these factors can be impacted upon via various interventions [1, 4].

Although physical inactivity or a sedentary lifestyle is one of the major risk factors for developing CVD, physical activity has proved especially useful in the overall prevention and treatment of CVD [4]. Problematically, despite strong scientific evidence supporting the benefits of regular physical activity for the prevention and management of CVD, physical inactivity is highly prevalent worldwide.

In addition, while it is known that physical activity is a critical intervention in the prevention and management of CVD, numerous types of modalities of physical activity exist. This includes, amongst others, aerobic exercise including walking, jogging, swimming, skipping rope, muscular fitness training including, strength training, power training, hypertrophy training, muscle endurance training, flexibility exercises, balance exercises, martial arts, and other physical fitness systems, including Pilates, Yoga and CrossFit. This sheer diversity of physical activity and the various variables of exercise programme design, which are exercise selection, intensity, repetitions, tempo, rest interval, sets and frequency of exercise sessions further complicate our understanding of what physical activity actually works or is best for the prevention and management of CVD in general, or for a specific type of CVD [4].

#### **1.1 Health benefits of physical activity**

Regular physical activity has an ancient association with general health and today it is unquestionable by all those involved in healthcare that regular physical activity provides many physical and psychological benefits. In this regard, >100,000 studies demonstrate positive associations between exercise and health [6]. In fact, overwhelming evidence exists that regular physical activity is associated with delaying the onset of 40 chronic conditions/diseases [7]. As such, exercise has proven to be a critical medical intervention even in diseases with a non-locomotor component. Specifically, a significant amount of scientific evidence has established a causal relationship between non-communicable diseases (NCD) and physical activity. This is especially important in that NCDs, such as CVD, diabetes and cancer, cause 65% of all deaths worldwide and are projected to result in >75% of all deaths by 2030 [8].

The success of physical activity in preventing, delaying and rehabilitating a multitude of chronic conditions/diseases relates to physical activity's multisystem responses. While the benefits of physical activity have been attributed to several mechanisms, including improved blood hemodynamics [9], improved levels of circulating lipids [10], increased cardiorespiratory fitness (CRF) [11, 12] and a reduced adiposity and enhanced muscle mass [13], more recent research has shown that during physical activity, proteins, peptides, enzymes and metabolites are released from one organ (mainly contracting skeletal muscle) to affect the metabolism in another organ [14].

#### **1.2 Physical activity and CVD**

Regular physical activity has a long scientific association with a reduced risk of CVD [15]. Two of the most well-known such studies demonstrating the importance of physical activity in preventing CVD are the Framingham Heart Study and London Transport Workers Study.

Prior to the Framingham Heart Study began in 1948 in Framingham, Massachusetts, little was known about the epidemiology of CVD. However, that study demonstrated much of the now-common knowledge concerning CVD,

#### *Importance of Resistance Training in the Management of Cardiovascular Disease Risk DOI: http://dx.doi.org/10.5772/intechopen.99710*

such as the effects of physical activity on CVD. In fact, the Framingham Heart Study is the source of the term risk factor [16]. The London Transport Workers Study, published in 1953 by Jeremy N. Morris was the first rigorous epidemiological study investigating physical activity and CVD risk. In that study, drivers and conductors of the London Transport Executive were compared and CVD rates were found to be increased in physically inactive bus drivers versus active conductors [17, 18].

More recently, many leading international organisations have recognised the importance of physical activity as medicine in not only improving health, but also preventing and managing CVD and have issued calls to action to make physical activity a priority in this regard [19, 20].

In addition to its independent effects on traditional CVD risk factors, regular physical activity can also improve cardiovascular health and impact upon nontraditional or novel CVD risk factors, such as C-reactive protein and oxidative stress [21, 22]. Physical activities' effectiveness at preventing and managing CVD is due to its ability to target various pathways through which it influences different physiological systems, such as its ability to promote a healthy anti-inflammatory environment, largely through the release of muscle-derived myokines, its ability to stimulate myocardial regeneration and its ability to improve age-related loss of muscle mass and strength, a frequently overlooked non-traditional CVD risk factor [23–25].

What is particularly noteworthy about physical activity's role in CVD prevention and management are the findings that even a single session or brief periods of physical activity are known to be associated with improvements in cardiovascular health parameters [26], such as an immediate decrease in blood pressure, also called post-exercise hypotension (PEH) [27], improved blood levels of lipids [28], enhanced fat oxidation [29] and improved insulin sensitivity [30].
