The effect of lifelong exercise dose on cardiovascular function during exercise.
An increased "dose" of endurance exercise training is associated with a greater maximal oxygen uptake (Vo2max), a larger left ventricular (LV) mass, and improved heart rate and blood pressure control. However, the effect of lifelong exercise dose on metabolic and hemodynamic response during exercise has not been previously examined. We performed a cross-sectional study on 101 (69 men) seniors (60 yr and older) focusing on lifelong exercise frequency as an index of exercise dose. These included 27 who had performed ≤ 2 exercise sessions/wk (sedentary), 25 who performed 2-3 sessions/wk (casual), 24 who performed 4-5 sessions/wk (committed) and 25 who performed ≥ 6 sessions/wk plus regular competitions (Masters athletes) over at least the last 25 yr. Oxygen uptake and hemodynamics [cardiac output, stroke volume (SV)] were collected at rest, two levels of steady-state submaximal exercise, and maximal exercise. Doppler ultrasound measures of LV diastolic filling were assessed at rest and during LV loading (saline infusion) to simulate increased LV filling. Body composition, total blood volume, and heart rate recovery after maximal exercise were also examined. Vo2max increased in a dose-dependent manner (P < 0.05). At maximal exercise, cardiac output and SV were largest in committed exercisers and Masters athletes (P < 0.05), while arteriovenous oxygen difference was greater in all trained groups (P < 0.05). At maximal exercise, effective arterial elastance, an index of ventricular-arterial coupling, was lower in committed exercisers and Masters athletes (P < 0.05). Doppler measures of LV filling were not enhanced at any condition, irrespective of lifelong exercise frequency. These data suggest that performing four or more weekly endurance exercise sessions over a lifetime results in significant gains in Vo2max, SV, and heart rate regulation during exercise; however, improved SV regulation during exercise is not coupled with favorable effects on LV filling, even when the heart is fully loaded.
University of Auckland, Auckland, New Zealand;
Graeme
G
Carrick-Ranson
Jeffrey L
JL
Hastings
Paul S
PS
Bhella
Naoki
N
Fujimoto
Shigeki
S
Shibata
M Dean
MD
Palmer
Kara
K
Boyd
Sheryl
S
Livingston
Erika
E
Dijk
Benjamin D
BD
Levine
D000222:Adaptation, Physiological; D000367:Age Factors; D000368:Aged; D000375:Aging; D003430:Cross-Sectional Studies; D015150:Echocardiography, Doppler; D004734:Energy Metabolism; D015444:Exercise; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006304:Health Status; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D020127:Recovery of Function; D057185:Sedentary Behavior; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left
aging; diastole; lifelong exercise; maximal exercise capacity; stroke volume