Aerobic exercise running

Data suggest that extensive physical exercise may increase blood plasma TAC. Long-term effects of systematic physical exercise are, however, controversial. Sub-maximal exercise (30 min) was reported not to alter blood plasma TAC significantly (A7). TAC of blood plasma was reported to increase immediately after a marathon run (by 25%) and this increase persisted 4 days later (by 12%) (L19). Similar effects (increase by 19%) were noted after a half-marathon (C29). Another study reported an increase in blood serum TAC by 22% during a 31-km run and by 16% during a marathon (V10). TAC of blood plasma was increased by 25% after a maximum aerobic exercise test and by 9% after a nonaerobic isometric exercise test (A8). Eccentric muscle exercise (70 maximal voluntary eccentric muscle actions on an isokinetic dynamometer, using the knee extensors of a single leg) did not affect blood serum TAC (C27). In another study, TAC increased after exhaustive aerobic (by 25%) and nonaerobic isometric exercise (by 9%) (A8). 

HPI KG is a 39-year-old woman with asthma on fluticasone and albuterol complaining of SOB associated with exercise. Three months ago she started an aerobic exercise program that has been hampered by chest tightness and SOB shortly after she begins running. She admits to poor compliance with her corticosteroid inhaler and requests an oral medication to control her asthma symptoms. Her PMH is significant for mild, persistent asthma for 35 years and allergic rhinitis. Her medications include fluticasone and albuterol inhalers and fexofenadine. Pulmonary function tests (PFTs) reveal her forced expiratory volume in the first second (FEV,) = 89% of predicted. 

Otto Shape, a 26-year-old medical student, has faithfully followed his diet and aerobic exercise program of daily tennis and jogging (see Chapter 19). He has lost a total of 33 lb and is just 23 lb from his college weight of 154 lb. His exercise capacity has markedly improved he can run for a longer time at a faster pace before noting shortness of breath or palpitations of his heart. Even his test scores in his medical school classes have improved. 

During NCR a clear reduction of IMCL in both muscles was observed (about 20%, spectra not shown), which was even more prominent after M (about 50-60%, Fig. 28a). In contrast to this, IMCL were nearly unchanged after HM (Fig. 28b). The mean reduction of IMCL in all subjects is given in Fig. 28c. The studies show that decline of IMCL levels depends on exercise intensity, as a marked decrease in IMCL after exercise of similar duration is only observable at lower aerobic workloads (NCR vs. HM). IMCL reduction also depends on exercise duration, as shown by the greater decline after the marathon run (M = 225 min) compared to the non-competitive exercise bout (NCR =106 min). 

The ATP can then power another contraction. Eventually, the amount of ATP available approaches a level too low to be bound by myosin in the muscle, even though it is by no means exhausted. The protons (acid) from metabolism cause hemoglobin to release its oxygen more readily, promoting a switch to aerobic metabolism. Lactate and protons from glycolysis may also lead to fatigue and an inability to sustain the level of speed that was possible earlier. In most humans, this seems to occur after a run of about 400 meters, which is why running quarters is one of the most unpleasant exercises for any athlete, no matter how well conditioned. 

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