Overall, 309 patients (18.4%) had an arrhythmia; the most common type of arrhythmia was atrial fibrillation, which occurred in 266 patients (86.1%). More patients had an arrhythmia, especially atrial fibrillation, in the dopamine group than in the norepinephrine group (Table 3). The study drug was discontinued in 65 patients owing to severe arrhythmias — 52 patients (6.1%) in the dopamine group and 13 patients (1.6%) in the norepinephrine group (P<0.001). These patients were included in the intention-to-treat analysis. There were no significant differences between the groups in the incidences of other adverse events.
Also, using the lifting (concentric) phase of these exercises only, rather than both lowering and lifting phases, *might* further improve results. This is partly because lifting phases involve faster rate coding, and partly because this strategy might potentially help avoid optimizing stretch-shortening cycle function for lifting heavy weights, rather than for jumping.
Athletes often do depth jumps with two plyo boxes: one to step off of and another to jump onto. Essentially, it’s a depth jump into a box jump. When doing this variation, make sure to leave enough room between the boxes to allow you to land and jump safely (3–5 feet between boxes should work). To advance within this progression, increase the height of the second box gradually as you develop more strength and power.
Less helpful was my early realization that I was a two-hand dunker, in light of my inability to palm a basketball on the move. It’s common knowledge among dunkers that throwing down with two hands is typically harder than with one; the former requires a higher vertical leap. So as I flailed haplessly at the rim last spring with one hand, I felt not just discouragement but also fear. Fear that I would miss big chunks of my kids’ ninth, sixth, and first years on earth just so I could come up embarrassingly short on a senseless goal that my wife and I would later estimate consumed 15 to 20 hours a week, on top of my normal work hours. And fear that I had shared this idea with my editors way too soon.
Circulatory shock is a life-threatening condition that is associated with high mortality.1,2 The administration of fluids, which is the first-line therapeutic strategy, is often insufficient to stabilize the patient's condition, and adrenergic agents are frequently required to correct hypotension. Among these agents, dopamine and norepinephrine are used most frequently.3 Both of these agents influence alpha-adrenergic and beta-adrenergic receptors, but to different degrees. Alpha-adrenergic effects increase vascular tone but may decrease cardiac output and regional blood flow, especially in cutaneous, splanchnic, and renal beds. Beta-adrenergic effects help to maintain blood flow through inotropic and chronotropic effects and to increase splanchnic perfusion. This beta-adrenergic stimulation can have unwanted consequences as well, including increased cellular metabolism and immunosuppressive effects. Dopamine also stimulates dopaminergic receptors, resulting in a proportionately greater increase in splanchnic and renal perfusion, and it may facilitate resolution of lung edema.4 However, dopaminergic stimulation can have harmful immunologic effects by altering hypothalamo–pituitary function, resulting in a marked decrease in prolactin and growth hormone levels. 5
An important component of maximizing height in a vertical jump is attributed to the use of counter-movements of the legs and arm swings prior to take off, as both of these actions have been shown to significantly increase the body’s center of mass rise. The counter-movement of the legs, a quick bend of the knees which lowers the center of mass prior to springing upwards, has been shown to improve jump height by 12% compared to jumping without the counter-movement. This is attributed to the stretch shortening cycle of the leg muscles enabling the muscles to create more contractile energy. Furthermore, jump height can be increased another 10% by executing arm swings during the take off phase of the jump compared to if no arm swings are utilized. This involves lowering the arms distally and posteriorly during the leg counter-movements, and powerfully thrusting the arms up and over the head as the leg extension phase begins. As the arms complete the swinging movement they pull up on the lower body causing the lower musculature to contract more rapidly, hence aiding in greater jump height. Despite these increases due to technical adjustments, it appears as if optimizing both the force producing and elastic properties of the musculotendinous system in the lower limbs is largely determined by genetics and partially mutable through resistance exercise training.