Improvement of cognitive function by mental and/or individualized aerobic training in healthy elderly subjects.

The aim of this study was to compare the effects of aerobic and mental training on cognitive function and to determine if the association of the two techniques shows better results. Thirty-two healthy elderly subjects (60 - 76 years) were assigned to one of four groups: aerobic training, mental training, combined aerobic and mental training and a control group. All subjects took two cognitive tests and an incremental exercise test before and after the training period. The intensity of exercise was individualized at the heart rate corresponding to the ventilatory threshold of each subject. After two months, the control group showed no alteration in physiological and cognitive variables. After the training period, the results showed a significant improvement in VO(2)max (F = 4.45, DF = 1, p < 0.05) of 12 % and 11 % in aerobic training and combined aerobic and mental training groups, respectively. Logical memory (F = 4.31, DF = 1, p < 0.05), as well as paired associates learning scores (F = 5.47, DF = 1, p < 0.05) and memory quotient (F = 6.52, DF = 1, p < 0.01) were significantly improved in the three trained groups. The mean difference in memory quotient between pre and post training was significantly higher in the combined aerobic and mental training group compared to aerobic training or mental training groups (F = 11.60, DF = 3, p < 0.001). We conclude that the specific aerobic training and mental training used in this study could induce the same degree of improvement in cognitive function and that combined training seemed to lead to greater effects than either technique alone.

Evaluation of quality of life in elderly healthy subjects after aerobic and/or mental training.

This study proposed different techniques of mental rehabilitation to healthy elderly subjects in order to assess the results in terms of subjectively perceived changes in quality of life. Thirty-two elderly subjects (60-76 years) were assigned to one of the four groups: aerobic training, mental training, combined aerobic and mental training and a control group. Before and after 2 months of training, all subjects took two memory tests. After training, a French validated questionnaire of quality of life was administered individually. Memory parameters such as logical memory (P<0.05), paired associated learning (P=0.05) and memory quotient (P=0.01) were enhanced in all groups except the control group, but in terms of quality of life all the elderly subjects were dissatisfied. VO(2max) and ventilatory threshold were significantly improved in the two groups who were engaged in a physical training program (AT and AMT) and these improvements were associated with a better quality of life in the domain of functional life. Association of the two techniques did not enhance the results for cognitive function. In conclusion, despite objective improvement in cognitive function, all subjects reported dissatisfaction in terms of improvement in quality of life, whatever their assigned group. Nevertheless, an improvement in quality of life was acknowledged after aerobic training for the physical component of functional life.

Effects of interval training at the ventilatory threshold on clinical and cardiorespiratory responses in elderly humans.

This study assessed clinical and cardiorespiratory responses after an interval training programme in sedentary elderly adults using the ventilatory threshold (Vth) as the index of exercise training intensity. A selection of 22 subjects were randomized into two groups: 11 subjects served as the training group (TG) and the others as controls (CG). Maximal exercise tests were performed on a treadmill before (T0), each month (T1, T2) and after the 3-month interval training programme period (T3). The TG subjects were individually trained at the heart rate corresponding to Vth measured at T0, T1 and T2 as the breakpoint in the oxygen uptake-carbon dioxide production relationship. Their training programme consisted of walking/jogging sessions on a running track twice a week. The sessions consisted of varying durations of exercise alternating with active recovery in such a way that the subjects slowly increased their total exercise time from an initial duration of 30 min to a final duration of 1 h. During training the heart rate was continuously monitored by a cardiofrequency meter. Compared with the daily activities of the controls, no training programme-related injuries were observed in TG. Moreover, programme adherence (73%) and attendance (97.3%) were high. The maximal oxygen uptake and Vth were increased in TG, by 20% (P<0.05) and 26% (P<0.01), respectively. Interval training at Vth also significantly increased maximal O2 pulse (P<0.05) and maximal ventilation (P<0.01). A significant decrease in submaximal ventilation (P<0.05) and heart rate (P<0.01) was also noted. These results would suggest that for untrained elderly adults, an interval training programme at the intensity of Vth may be well-tolerated clinically and may significantly improve both maximal aerobic power and submaximal exercise tolerance.

Effectiveness of individualized aerobic training at the ventilatory threshold in the elderly.

This study was designed to specify whether an individualized training program at the ventilatory threshold in elderly subjects produces greater training adaptations than a standardized training program performed at 50% of heart rate reserve. Sixteen subjects participated in the study. Maximal exercise tests were performed on a treadmill before and after the training program. Eight subjects trained at the ventilatory threshold (ITG) and eight trained at 50% of heart rate reserve (STG). The mean training heart rate was 129 +/- 14.2 bpm and 115 +/- 7.9 bpm in the individualized training group (ITG) and the standardized training group (STG), respectively. The maximal O2 uptake (VO2max) was improved significantly by 20% in ITG (within group p < .05), whereas no significant improvement was noted in STG. The improvement in ITG compared to the nonsignificant change in STG was significant (p < .05). In addition, submaximal ventilation and heart rate were more decreased in ITG than STG. We conclude that for elderly people an individualized training program at the level of the ventilatory threshold is significantly more effective in terms of VO2max and submaximal cardiorespiratory adaptations.

Pulse wave velocity measurement by cross-correlation of Doppler velocity signals. Application to elderly volunteers during training.

Pulse wave velocity (PWV) measurement is widely used for the indirect assessment of arterial wall distensibility. In order to improve its measurement technique, we built a system performing the calculation of the cross-correlation function of Doppler velocity signals. In 12 normal subjects and 10 patients, the mean difference between duplicate measurements was 0.7 +/- 7.8% (NS). We tested this technique in 15 elderly volunteers before and after a three months training period. Brachial and tibial systolic blood pressure decreased respectively from 18.1 +/- 2.2 kPa to 16.7 +/- 1.9 kPa (p = 0.008) and from 21.1 +/- 3.4 kPa to 18.4 +/- 2.5 kPa (p = 0.003), while lower limb PWV decreased from 8.96 +/- 1.26 to 7.92 +/- 1.22 m.s-1 (p = 0.016). Therefore, automatic PWV measurement using the cross-correlation technique allows to demonstrate training induced changes in PWV, although concomitant changes in blood pressure must be considered in their interpretation.

Anaerobic and aerobic peak power output and the force-velocity relationship in endurance-trained athletes: effects of aging.

The aim of this investigation was to test the hypothesis that the anaerobic peak power output (Pan, peak) declines more than the peak aerobic power (Paer, peak) with increasing age. In addition, the force-velocity (F-v) relationship was studied to determine which of these two factors is primarily responsible for the expected alterations in anaerobic power. The Pan, peak, the maximal F when v is equal to zero (F0) and the maximal v when F is equal to zero (v0) were assessed by F-v test i.e. a brief intense intermittent exercise test using incremental braking forces. The Paer, peak was measured by a maximal increment exercise test. A group of 12 young athletes (YA) and 12 master athletes (MA) mean age 24.8 (SEM 1.3) and 65.1 (SEM 1.2) years, respectively, participated in this study. The YA and MA had similar body masses, heights and endurance training schedules. The results showed that Pan, peak was 42.7% lower in the older subjects, corresponding to mean values of 1089 (SEM 40) compared to 624 (SEM 33) W (t = 8.9, P < 0.001) for YA compared to MA, respectively. The F0 and V0 indices showed values that were lower by 30.3% and 15.2%, respectively. The Paer, peak was 35% lower with mean values of 323 (SEM 12) W for YA compared to 210 (SEM 6) W for MA (t = 8.3, P < 0.001). The mean maximal oxygen uptake was 34.7% lower with 4240 (SEM 160) ml.min-1 for YA compared to 2770 (SEM 120) ml.min-1 for MA (t = 7.2, P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise-induced hypoxemia in older athletes.

To determine whether exercise induces hypoxemia in highly trained older "master" athletes (MA), as it does in certain elite endurance-trained young athletes (YA), 10 MA (65.3 +/- 2.6 yr), 10 control subjects (CS; 68.3 +/- 2.2 yr), and 10 endurance-trained YA (23.3 +/- 1.1 yr) performed an incremental exercise test. During testing, blood samples for arterial blood gas analysis were drawn during the last 20 s of each load. Lung exchanges were measured using a breath-by-breath automated exercise device. Exercise-induced hypoxemia (EIH) appeared in all MA and 8 of 10 YA, whereas there were no changes in the blood gases of CS. In MA, arterial PO2 decreased significantly from 40% of maximal O2 uptake onward and was associated with a significant increase in the ideal alveolar-arterial O2 difference from 60% onward. The MA also showed a lower ventilation for a given absolute load compared with CS. In all subjects arterial PCO2 rose slightly but significantly during the work, but this increase was most marked in MA. The EIH differed between MA and YA in the following ways: 1) all MA showed a drop in arterial PO2 during exercise, 2) this drop appeared earlier and was significantly greater for a given load in MA, and 3) EIH appeared at a lower level of training regimen in MA. This hypoxemia was at first isolated, probably at least partially due to relative hypoventilation, and then was associated with a widened ideal alveolar-arterial O2 difference, which may have been due to an increase in extravascular lung water.(ABSTRACT TRUNCATED AT 250 WORDS)

Age and training effects on the lactate kinetics of master athletes during maximal exercise.

To study the effects of age and training on lactate production in older trained subjects, the lactate kinetics of highly trained cyclists [HT, n = 7; 65 (SEM 1.2) years] and control subjects with low training (LT, n = 7) and of similar age were compared to those of young athletes [YA, n = 7; 26 (SEM 0.7) years], during an incremental exercise test to maximum power. The results showed that the lactacidaemia at maximal oxygen uptake (VO2max) was lower for HT than for LT (P < 0.05) and, in both cases, lower than that of YA (P < 0.001). The respective values were HT: 3.9 (SEM 0.51), LT: 5.36 (SEM 1.12), and YA: 10.3 (SEM 0.63) mmol.l-1. At submaximal powers, however, the difference in lactacidaemia was not significant between HT and YA, although the values for lactacidaemia at VO2max calculated per watt and per watt normalized by body mass were significantly lower for HT (P < 0.001) and LT (P < 0.02). These results would indicate that the decline in power with age induced a decline in lactacidaemia. Yet this loss in power was not the only causative factor; indeed, our results indicated a complementary metabolic influence. In the older subjects training decreased significantly the lactacidaemia for the same submaximal power (P < 0.01) and from 60% of VO2max onwards (P < 0.05); as for YA it postponed the increase and accumulation of lactates. The lactate increase threshold (Thla-,1) was found at 46% VO2max for LT and at 56% VO2max for HT.(ABSTRACT TRUNCATED AT 250 WORDS)