Endurance exercise training augments diastolic filling at rest and during exercise in healthy young and older men.

Background. Diastolic filling atrest isaltered markedly withadvancing age. Whether exercise training canimprove diastolic filling atrest orduring exercise ineither healthy older orhealthy youngmenhas notbeendetermined. Thepurpose ofthis study wastodetermine if6months ofaerobic exercise training improves diastolic filling. Methods andResults. Radionuclide diastolic filling parameters weremeasured atrestandduring exercise in14older (age, 60to82years) and17young(age, 24to32years) rigorously screened healthy malesbefore exercise training andin13older and11youngmenafter 6monthsofendurance exercise training. Diastolic filling rates wereexpressed intwoways, asabsolute milliliters ofblood(mL*s'lm-2) andnormalized totheend-diastolic volume. Atbaseline, thepeakearly filling rates werelower intheolder groupcompared withtheyounggroupasexpressed inabsolute milliliters ofblood(older, 85±7 mL *solm-2; young, 173+10mL *s'lm-2; P<.0001) andinend-diastolic volume persecond (1.66+0.11 versus2.55±0.08, P<.0001), whereas thepeakatrial filling rates weregreater inabsolute milliliters of blood(85±5 versus56±7mL-s'lm-2,P=.003) andinend-diastolic volumepersecond(1.70±0.12 versus 0.80+0.06, P<.0001). During exercise, atanygiven heart rate, theolder grouphadalower peak filling ratethantheyounggroup. Also, atpeakexercise, thesingle peakfilling ratewasdecreased inthe older groupinmL.S m-2(384±19 versus565±36 mL-s'm-2, P=.0002) andinend-diastolic volume persecond (6.01±0.25 versus 7.91+0.28 end-diastolic volume persecond, P<.0001). Sixmonths ofintensive aerobic exercise training hadsimilar effects intheoldandyounggroups overall. Maximal oxygenconsumption increased 19%(ANOVAtraining effect, P<.0001) andechocardiographic left ventricular massincreased 8%(ANOVAtraining effect, P=.002). Training increased theresting peak early filling rateinabsolute milliliters ofblood by+14%(ANOVAtraining effect, P=.02). During exercise, thepeakeariy orsingle peakfilling rateatanygiven heart ratewasincreased. Atpeakexercise, thesingle peakfilling ratewasincreased by14%inmL s1 - mI2(ANOVAtraining effect, P=.0004). Theonly age-related differential effect oftraining wasonthepeakatrial filling rateinend-diastolic volume per second, which decreased by27%intheolder group butwasunchanged intheyoung(+5%)(ANOVA young versusolder, P=.001). Theindependent predictors ofa greater maximaloxygenconsumption by multivariate analysis wereahigher peakexercise heart rate, agreater resting peak early filling rate, the exercise trained state, andayounger age. Conclusions. Healthy older menhavereduced early diastolic filling atrest andduring exercise compared withyoungmen.Endurance exercise training enhances early diastolic filling atrestandduring exercise inboththeoldandtheyoung. Training reduces theelevated resting atrial filling rateintheold, whereas theyoungwereunchanged. Thetraining-induced augmentation ofearly diastolic filling atrestandduring exercise maybeanimportant adaptation toallow anincrease instroke volume atrestandanincrease in stroke volume, cardiac output, andmaximaloxygenconsumption during exercise. (Circulation 1993;88:116-126)