**1.5 Safety of resistance training in the management of cardiovascular disease risk**

Resistance training is an exercise modality that can potentially target many of the adverse effects of CVD. However, there have been concerns regarding the safety of strenuous RT and its application to existing and future clinical interventions.

In the past, RT has been regarded as hazardous due to inflated blood pressure responses, elevated double pressure products and an increase in ischemic events. However, more recent research has demonstrated that RT may be less risky than was once assumed. In this regard, previous research has established intra-arterial blood pressures during RT in cardiac patients to be within a clinically tolerable range at 40–60% of 1-RM [72, 73]. Further, research has also demonstrated that electrocardiographic (ECG) responses during RT at 20%, 40%, 60%, and 80% of 1-RM failed to induce clinically significant ST-segment depression, angina or ventricular arrhythmias [74]. In fact, RT has not been found elicit significant cardiovascular events even during 1-RM determination [75]. As such, light-to-moderate RT can be deemed safe for low- to moderate-risk CVD patients.

With regards to the use of RT in high-risk CVD patients, even though traditional RT participation guidelines have previously advised that surgical and post–myocardial infarction (MI) patients should avoid RT for at least four to six months [76], it has been demonstrated that these patients can safely complete static-dynamic

activity corresponding to carrying up to 30 pounds or about 13 kilogrammes by three weeks after an acute MI [77]. As such, it is probable that RT could be introduced earlier in even these high-risk settings should low-load programmes be prescribed.

While moderate to good left ventricular function and cardiorespiratory fitness in the absence of anginal symptoms or ischemic ST-segment depression have been proposed as preconditions for participation in RT, contraindications to RT comprise unstable angina, uncontrolled hypertension (systolic blood pressure ≥ 160 mm/Hg and/or diastolic blood pressure ≥ 100 mm/Hg), uncontrolled dysrhythmias, recent history of congestive heart failure that has not been evaluated and effectively treated, severe stenotic or regurgitant valvular disease and hypertrophic cardiomyopathy [78].
