Protein and carbohydrate supplementation after exercise increases plasma volume and albumin content in older and young men.

This study examined whether increased plasma volume (PV) and albumin content (Alb(cont)) in plasma for 23 h after exercise were attenuated in older subjects compared with in young adult subjects, and if this attenuation abated by supplementation with protein and carbohydrate (CHO) immediately after exercise. Eight moderately active older (approximately 68 yr) and 8 young (approximately 21 yr) men performed two trials: control (CNT) and Pro-CHO in which subjects consumed placebo (0.5 kcal, 0 g protein, 0.5 mg Na(+) in 3.2 ml total fluid volume/kg body wt) or protein and CHO mixture (3.2 kcal, 0.18 g protein, 0.5 mg Na(+) in 3.2 ml total fluid volume/kg body wt) supplementations, respectively, immediately after high-intensity interval exercise for 72 min [8 sets of 4 min at 70-80% peak oxygen consumption rate (Vo(2peak)) intermitted by 5 min at 20% Vo(2peak)]. PV, Alb(cont), and plasma globulin content (Glb(cont)) were measured before exercise, at the end of exercise, every hour from the 1st to the 5th hour after exercise, and at the 23rd hour after exercise. From 12 h before the start to the end of experiment, food intake was controlled to the age-matched recommended dietary allowances. We found that during the first 4 h after exercise in CNT, Alb(cont) recovered less in the older than the young group by approximately 0.04 g/kg (P < 0.05), while it generally recovered more with Pro-CHO than CNT by approximately 0.09 and approximately 0.04 g/kg in the young and older group, respectively, accompanied by a greater increase in PV by approximately 1 and approximately 2 ml/kg, respectively, during the 23 h after exercise (P < 0.05). Glb(cont) remained constant throughout the experiment in both trials for both age groups. Thus the attenuated responses of Alb(cont) and PV after exercise in older subjects were restored by protein and CHO supplementation immediately after exercise, similarly to young subjects.

Impact of protein and carbohydrate supplementation on plasma volume expansion and thermoregulatory adaptation by aerobic training in older men.

We examined whether protein-carbohydrate (CHO) supplementation immediately after exercise each day during aerobic training facilitated plasma volume (PV) expansion and thermoregulatory and cardiovascular adaptations in older men. Fourteen moderately active older men [68 +/- 5 (SD) yr] were divided into two groups so as to have no significant differences in anthropometric measures, PV, and peak oxygen consumption rate (Vo(2peak)). Each group was provided with a mixture of protein and CHO (3.2 kcal, 0.18 g protein/kg body wt, Pro-CHO, n = 7) or a non-protein and low-calorie placebo (0.5 kcal, 0 g protein/kg body wt, CNT, n = 7) immediately after cycling exercise (60-75% Vo(2peak), 60 min/day, 3 days/wk) each day for 8 wk at approximately 19 degrees C ambient temperature (T(a)) and approximately 43% relative humidity (RH). Before and after training, we measured PV, cardiac stroke volume (SV), and esophageal temperature (T(es)) during 20-min exercise at 60% of pretraining Vo(2peak) at 30 degrees C T(a) and 50% RH. Moreover, we determined the sensitivity of the chest sweat rate (DeltaSR/DeltaT(es)) and forearm vascular conductance (DeltaFVC/DeltaT(es)) in response to increased T(es) during exercise. After training, PV increased by approximately 6% in Pro-CHO (P < 0.001), with an approximately 10% increase in SV during exercise (P < 0.001), but not in CNT (P > 0.07). DeltaFVC/DeltaT(es) increased by 80% and DeltaSR/DeltaT(es) by 18% in Pro-CHO (both P < 0.01) but not in CNT (P > 0.07). Moreover, we found a significant interactive effect of group x training on PV, SV, and DeltaFVC/DeltaT(es) (all P < 0.02) but with no significant effect of group (P > 0.4), suggesting that the supplement enhanced these responses to aerobic training. Thus postexercise protein-CHO supplementation during training caused PV expansion and facilitated thermoregulatory and cardiovascular adaptations, possibly providing a new training regimen for older men.

Relation between fat distributions and several plasma adipocytokines after exercise training in premenopausal and postmenopausal women.

Circulating concentrations of adipocytokines, such as leptin, tumor necrosis factor-alpha (TNF-alpha), and plasminogen activator inhibitor-1 (PAI-1), vary with exercise training, menopause, or regional variations in adipose tissues. In the present study, the relationships between body fat distributions and some adipocytokines were compared in premenopausal (N = 9) and postmenopausal women (N = 9), before and after exercise training. The training for 10 weeks (that is, 3 days/week) consisted of aqua exercise plus resistance exercise. The training reduced percent fat, body mass index, total fat mass (TFM), subcutaneous fat mass (SFM), and plasma levels of leptin and PAI-1 in both women. Mean value of plasma TNF-alpha tended to increase after training in both women. Plasma leptin levels were lower in postmenopausal than in premenopausal women, independently of training. In premenopausal women, plasma leptin levels correlated well with either TFM or SFM before and after training. Regression analysis of decreases in plasma leptin with a reduced amount of SFM revealed that decreases in plasma leptin depended to a greater extent on a loss of SFM. In postmenopausal women, no significant correlation was found between leptin levels and any of the fat depots. Plasma TNF-alpha levels correlated well with visceral fat mass (VFM) in premenopausal but not in postmenopausal women. Changes in TNF-alpha levels after training correlated well with reduced amount of VFM in premenopausal but not in postmenopausal women. Plasma PAI-1 levels were not different between groups. Moreover, no significant correlation was found between PAI-1 levels and any of the fat depots in both women. Thus, in premenopausal but not in postmenopausal women, changes in plasma concentrations of leptin and TNF-alpha correlate well with specific alterations in relative amount of SFM and VFM after training, respectively. However, no significant relationship between PAI-1 and any of the fat depots was found independently of either menopause or training.