Longer Training Duration Research Articles

ASTHMA AND EXERCISE IN THE ELDERLY

Participation in regular physical activity, with the goal of enhancing functional ability and fitness, is associated with measurable health-enhancing and psychologic benefits. Various types of exercise are now actively prescribed by the medical community for the prevention and treatment of a number of diseases. 66 Obstructive pulmonary disease, including both chronic obstructive pulmonary disease (COPD) and asthma, is a significant cause of functional disability in older adults that is often characterized clinically by progressive breathlessness and increasing physical limitations. Whether exercise training improves aerobic capacity in elderly COPD patients and, in some cases, those with reactive airway disease, still remains unclear. 100 Earlier studies failed to demonstrate this effect, but more recent investigations 40 , 51 using higher levels of intensity or longer duration of training appear to improve functional capacity in older patients with moderate obstructive lung disease (Table 1) . In this article we examine how asthma, or reactive airflow obstruction, alters physical capacity and human performance in the elderly, and the role of exercise training in the management of reactive airways disease among older patients.

Progressive effect of endurance training on metabolic adaptations in working skeletal muscle.

We investigated the hypothesis that a program of prolonged endurance training, previously shown to decrease metabolic perturbations to acute exercise within 5 days of training, would result in greater metabolic adaptations after a longer training duration. Seven healthy male volunteers [O2 consumption = 3.52 +/- 0.20 (SE) l/min] engaged in a training program consisting of 2 h of cycle exercise at 59% of pretraining peak O2 consumption (VO2peak) 5-6 times/wk. Responses to a 90-min submaximal exercise challenge were assessed pretraining (PRE) and after 5 and 31 days of training. On the basis of biopsies obtained from the vastus lateralis muscle, it was found that, after 5 days of training, muscle lactate concentration, phosphocreatine (PCr) hydrolysis, and glycogen depletion were reduced vs. PRE (all P < 0.01). Further training (26 days) showed that, at 31 days, the reduction in PCr and the accumulation of muscle lactate was even less than at 5 days (P < 0.01). Muscle oxidative potential, estimated from the maximal activity of succinate dehydrogenase, was increased only after 31 days of training (+41%; P < 0.01). In addition, VO2peak was only increased (10%) by 31 days (P < 0.05). The results show that a period of short-term training results in many characteristic training adaptations but that these adaptations occurred before increases in mitochondrial potential. However, a further period of training resulted in further adaptations in muscle metabolism and muscle phosphorylation potential, which were linked to the increase in muscle mitochondrial capacity.

Effects and adverse effects of autonomic blockade in physical exercise

Training bradycardia during autonomic blockade has been studied in rats and humans. The heart rate after autonomic blockade (intrinsic heart rate) is also lowered as a part of the adaptation to training. However, this nonautonomic component of the cardiac adaptation requires a long duration of intense endurance training to appear. This is in contrast to the autonomic component of the training bradycardia. From animal studies we have concluded that even if the training bradycardia is due to an adaptation within the heart itself, the adrenergic nerves are important for the development of a slow intrinsic heart rate. Neither the β-receptor stimulation nor the degree of the heart rate increase during exercise is the main stimulus for the development of a training-induced bradycardia. Well-trained bicyclists had an intrinsic heart rate 20 beats lower than untrained normal control subjects. The heart rate at rest and the maximal heart rate were also on an average 20 beats lower for the bicyclists. There was no significant difference between propranolol and the β 1 selective metoprolol in this study regarding their effects on heart rate and on deterioration of the maximal oxygen consumption after blockade. This deterioration was more marked in the well-trained than in the sedentary group. Based upon studies both in normal subjects and patients a careful rating of symptoms including physical exertion, fatigue or pain in the legs, dyspnea and chest pain using a Borg scale is recommended during exercise testing with β blockade. This should facilitate a more optimal and individual prescription and avoid use of β blockers in subgroups of patients with such symptoms as leg fatigue, pain or breathlessness during exercise and β blockade.

Experimental-longitudinal methods in assessment, research, and treatment.

The experimental-longitudinal methods to be described here have a long history of development (Staats, 1957, 1963, 1968, 1975, 1977). The present author, to begin, made the first behavior analyses for the modification of problem behaviors, analyses which were formally verified by Ayllon and Michael (1959). Relatively simple behaviors and (primarily) social reinforcers were employed in the author's early demonstrations and in Ayllon and Michael's study. These are not apropos, however, to the complex human behaviors that are acquired over long periods of time. On the one hand, Skinner's (Ferster & Skinner, 1957; Sidman, 1960)singlesubject research methodology with animals is not appropriate with long-term learning involving complex, variegated stimuli and behaviors. But on the other hand, neither are the group methods of traditional experimental psychology. Traditional educational research, while dealing with complex learning tasks and behavior, sometimes over long periods of time, does not analyze training procedures and achievements in detail. Further, although longitudinal studies have been made in child development, the conditions that produce such development have not been specifically observed, on the assumption that much of development is due to maturation. These various methods of research thushave provided important knowledge, but they do not answer questions concerning specific training procedures for specific behavioral skills involving complex learning procedures and long duration of training, where repertoires of skills, instead of simple responses, are involved, possibly arranged in hierarchical order with one repertoire basic to the next (see Staats, 1968). In continuing the work he had introduced, the author extended the principles of classical and instrumental conditioning to more complex functional behaviors by use of the experimental-longitudinal methods first developed in naturalistic situations involving his own infant child. Behavior analyses were first made of a number of behavioral repertoires, and the author then devised training 323