Effects of Chronic Overload Training and Aging on Left Ventricular Systolic Function

Abstract

To examine the effects of age and chronic overload training on left ventricular systolic function during static exercise, Doppler echocardiography studies were performed in 14 young (28 ± 6 years) and 10 older (51 ± 3 years) weight lifters and also in 14 young (29 ± 6 years) and 10 older (52 ± 1.1 years) normal individuals during upright dead-lift isometric exercise, at 30% of maximal voluntary contraction for 3 min. At rest, older weight lifters demonstrated impaired left ventricular systolic function as compared with the other three groups. During exercise, peak and mean velocity values increased significantly (p < 0.05) from resting values in the young groups, but remained unchanged in the older groups. Flow period and acceleration and deceleration times were significantly (p < 0.05) lower in the younger subjects than those observed for the old ones, with the highest (p < 0.05) values obtained by the old weight lifters. This study suggests that the differences between the groups are related to differences in impedance and not to fundamental changes in the properties of the myocardium.

A Review of the Acute Cardiovascular Responses to Resistance Exercise of Healthy Young and Older Adults

“…However, MacDougall and associates (24) suggest that resistance exercise is analogous to a series of static contractions that are performed dynamically. The major-ity of research comparing the effects of age on acute resistance exercise has been conducted using isometric exercise (36, 38-40, 43, 49, 51); this is probably due to the more stringent control associated with this exercise and with the ability to generalize this type of exercise to everyday tasks (38).…”

“…In order to determine the acute HR response to training status and age, Sagiv et al (38) compared the effect of a dead lift isometric exercise, held at 30% of MVC for 3 minutes, in 14 younger (28 Ϯ 6.0 years) and 10 older (51 Ϯ 3.0 years) weight lifters and in 14 younger (29 Ϯ 6.0 years) and 10 older (52 Ϯ 1.1 years) ''normal'' individuals. During the dead lift, all subjects increased mean peak HR significantly from rest (but not between groups), attaining values of 94.2 Ϯ 8, 96.0 Ϯ 9, 90.4 Ϯ 10, and 89.1 Ϯ 6 bpm for the young normals, young weight lifters, old normals, and old weight lifters, respectively.…”

“…Resistance exercise, in contrast to aerobic exercise, imposes an increased afterload stress on the heart, which produces only minimal variations in SV (13,22,31). In general, SV remains unchanged during light work (11,38), while reductions occur at a greater % MVC (1,20). High intensity muscle contraction results in decreased preload, increased afterload, and overall diminished SV response (29).…”

“…Research reporting SV comparisons using submaximal isometric contractions for 3 minutes has shown minor increases from rest, ranging from 2.6-6.2% for younger and from 1.0-13% for older adults (37,38,40,42). Using echocardiography, Sagiv et al (42) observed slight increases of 6 and 13%, respectively, in the younger (23 Ϯ 3.0 years) and older (67 Ϯ 4.0 years) subjects during isometric handgrip and negligible increases from rest while performing a dead lift exercise (younger 4%; elderly 3%).…”

Safety of resistance training in the elderly

“…Thus, light to moderate resistive training exercise can be considered safe for low-risk cardiac patients. Even the risk of developing compromised left ventricular function is less during a workout against weight resistance compared to that in conventional clinical aerobic exercise test [7]. Circuit weight training is an approach for strength development especially designed for the elderly.…”