Fat and carbohydrate metabolism during exercise in elderly and young subjects

1996 ◽  
Vol 271 (6) ◽  
pp. E983-E989 ◽  
Author(s):  
S. Sial ◽  
A. R. Coggan ◽  
R. Carroll ◽  
J. Goodwin ◽  
S. Klein

We evaluated the effect of aging on fat and carbohydrate metabolism during moderate intensity exercise. Glycerol, free fatty acid (FFA), and glucose rate of appearance (Ra) in plasma and substrate oxidation were determined during 60 min of cycle ergometer exercise in six elderly (73 +/- 2 yr) and six young adults (26 +/- 2 yr) matched by gender and lean body mass. The elderly group was studied during exercise performed at 56 +/- 3% of maximum oxygen uptake, whereas the young adults were studied during exercise performed at the same absolute and at a similar relative intensity as the elderly subjects. Mean fat oxidation during exercise was 25-35% lower in the elderly subjects than in the young adults exercising at either the same absolute or similar relative intensities (P < 0.05). Mean carbohydrate oxidation in the elderly group was 35% higher than the young adults exercising at the same absolute intensity (P < 0.001) but 40% lower than the young adults exercising at the same relative intensity (P < 0.001). Average FFA Ra in the elderly subjects was 85% higher than in the young adults exercising at the same absolute intensity (P < 0.05) but 35% lower than the young adults exercising at a similar relative intensity (P < 0.05). We conclude that fat oxidation is decreased while carbohydrate oxidation is increased during moderate intensity exercise in elderly men and women. The shift in substrate oxidation was caused by age-related changes in skeletal muscle respiratory capacity because lipolytic rates and FFA availability were not rate limiting in the older subjects.

2020 ◽  
Vol 8 (A) ◽  
pp. 230-233
Author(s):  
Gusbakti Rusip ◽  
Sri Mukti Suhartini

BACKGROUND: Sedentary lifestyle in the elderly decreases the function of cardiovascular system may lead reduction performance. Many previous studies reported that moderate intensity aerobic exercise was recommended for older persons because it may increases reactive oxygen species (ROS) at optimum level. The increasing of ROS can activate antioxidant mechanism against oxidatif stress due to exercise. AIM: The aim of this study was to investigate the change of glutathione peroxidase (GPx) activity and VO2max on moderate intensity aerobic exercise and its correlation. METHODS: The study design was quasi-experimental. Subjects were sedentary elderly women age 65 ± 5.06 years old. Total subject was 73 persons selected by consecutive sampling. Subjects did moderate intensity aerobic exercise for 12 weeks by walking for 30 min a day, 3 times a week at 50–85% of maximum heart rate. The parameters were measured on the baseline and 12 weeks after exercise. GPx activity from the plasma was examined by ELISA and the VO2max was measured by 6-min walking distance. The data were analyzed by unpaired t-test and Spearman test. RESULTS: GPx activity and VO2max were significantly increased about 41.75% and 24.11% (p < 0.05) on the experimental group, respectively. There was a correlation between GPx activity and VO2max (r = 0.223, p = 0.041). CONCLUSION: Regular moderate intensity aerobic exercise significantly increased GPx activity and VO2max. This kind of exercise is advised for the elderly because it can elevate antioxidant level as a defense against oxidative stress due to aging; therefore, it can improve aerobic capacity in the elderly.


2005 ◽  
Vol 98 (4) ◽  
pp. 1371-1378 ◽  
Author(s):  
Brendon J. Gurd ◽  
Barry W. Scheuermann ◽  
Donald H. Paterson ◽  
John M. Kowalchuk

The effect of prior heavy-intensity warm-up exercise on subsequent moderate-intensity phase 2 pulmonary O2 uptake kinetics (τV̇o2) was examined in young adults exhibiting relatively fast (FK; τV̇o2 < 30 s; n = 6) and slow (SK; τV̇o2 > 30 s; n = 6) V̇o2 kinetics in moderate-intensity exercise without prior warm up. Subjects performed four repetitions of a moderate (Mod1)-heavy-moderate (Mod2) protocol on a cycle ergometer with work rates corresponding to 80% estimated lactate threshold (moderate intensity) and 50% difference between lactate threshold and peak V̇o2 (heavy intensity); each transition lasted 6 min, and each was preceded by 6 min of cycling at 20 W. V̇o2 and heart rate (HR) were measured breath-by-breath and beat-by-beat, respectively; concentration changes of muscle deoxyhemoglobin (HHb), oxyhemoglobin, and total hemoglobin were measured by near-infrared spectroscopy (Hamamatsu NIRO 300). τV̇o2 was lower ( P < 0.05) in Mod2 than in Mod1 in both FK (20 ± 5 s vs. 26 ± 5 s, respectively) and SK (30 ± 8 s vs. 45 ± 11 s, respectively); linear regression analysis showed a greater “speeding” of V̇o2 kinetics in subjects exhibiting a greater Mod1 τV̇o2. HR, oxyhemoglobin, and total hemoglobin were elevated ( P < 0.05) in Mod2 compared with Mod1. The delay before the increase in HHb was reduced ( P < 0.05) in Mod2, whereas the HHb mean response time was reduced ( P < 0.05) in FK (Mod2, 22 ± 3 s; Mod1, 32 ± 11 s) but not different in SK (Mod2, 36 ± 13 s; Mod1, 34 ± 15 s). We conclude that improved muscle perfusion in Mod2 may have contributed to the faster adaptation of V̇o2, especially in SK; however, a possible role for metabolic inertia in some subjects cannot be overlooked.


2008 ◽  
Vol 294 (2) ◽  
pp. R577-R584 ◽  
Author(s):  
B. J. Gurd ◽  
S. J. Peters ◽  
G. J. F. Heigenhauser ◽  
P. J. LeBlanc ◽  
T. J. Doherty ◽  
...  

The adaptation of pulmonary O2 uptake (V̇o2p) kinetics is slowed in older compared with young adults during the transition to moderate-intensity exercise. In this study, we examined the relationship between V̇o2p kinetics and mitochondrial pyruvate dehydrogenase (PDH) activity in young ( n = 7) and older ( n = 6) adults. Subjects performed cycle exercise to a work rate corresponding to ∼90% of estimated lactate threshold. Phase 2 V̇o2p kinetics were slower ( P < 0.05) in older (τ = 40 ± 17 s) compared with young (τ = 21 ± 6 s) adults. Relative phosphocreatine (PCr) breakdown was greater ( P < 0.05) at 30 s in older compared with young adults. Absolute PCr breakdown at 6 min was greater ( P < 0.05) in older compared with young adults. In young adults, PDH activity increased ( P < 0.05) from baseline to 30 s, with no further change observed at 6 min. In older adults, PDH activity during baseline exercise was similar to that seen in young adults. During the exercise transition, PDH activity did not increase ( P > 0.05) at 30 s of exercise but was elevated ( P < 0.05) after 6 min. The change in deoxyhemoglobin (HHb) was greater for a given V̇o2p in older adults, and there was a similar time course of HHb accompanying the slower V̇o2p kinetics in the older adults, suggesting a slower adaptation of bulk O2 delivery in older adults. In conclusion, the slower adaptation of V̇o2p in older adults is likely a result of both an increased metabolic inertia and lower O2 availability.


Author(s):  
Bogdan-Alexandru Hagiu ◽  
Iulian Dumitru Turculeț ◽  
Iulian Marius Dumitru

"ABSTRACT. Independent studies suggest the possibility of prophylaxis of severe forms of COVID-19 through moderate-intensity exercise. There is the fear that intense exercise could increase the risk of the virus entering the cell, a determining factor being hypoxia. As a result, in this paper we aimed to assess the heart rate and oxygen saturation of the blood in the case of Kangoo Jumps and aerobic training at home. Kangoo Jumps workouts practiced in such a way as to avoid in principle the high intensity of the effort, do not produce transient hypoxia, not even in subjects whose heart rate indicated an intense effort. Preliminary data show that aerobics at home does not produce hypoxia in mature adults and the elderly, and heart rates do not exceed the limit of moderate intensity; however, additional studies are required for both categories of exercises under study."


1998 ◽  
Vol 274 (5) ◽  
pp. E785-E790 ◽  
Author(s):  
Shahid Sial ◽  
Andrew R. Coggan ◽  
Robert C. Hickner ◽  
Samuel Klein

Compared with young adults, fat oxidation is lower in elderly persons during endurance exercise performed at either the same absolute or relative intensity. We evaluated the effect of 16 wk of endurance training on fat and glucose metabolism during 60 min of moderate intensity exercise [50% of pretraining peak oxygen consumption (V˙o2 peak)] in six elderly men and women (74 ± 2 yr). Training caused a 21% increase in meanV˙o2 peak. The average rate of fat oxidation during exercise was greater after (221 ± 28 μmol/min) than before (166 ± 17 μmol/min) training ( P = 0.002), and the average rate of carbohydrate oxidation during exercise was lower after (3,180 ± 461 μmol/min) than before (3,937 ± 483 μmol/min) training ( P = 0.003). Training did not cause a significant change in glycerol rate of appearance (Ra), free fatty acid (FFA) Ra, and FFA rate of disappearance during exercise. However, glucose Raduring exercise was lower after (1,027 ± 95 μmol/min) than before (1,157 ± 69 μmol/min) training ( P = 0.01). These results demonstrate that a 16-wk period of endurance training increases fat oxidation without a significant change in lipolysis (glycerol Ra) or FFA availability (FFA Ra) during exercise in elderly subjects. Therefore, the training-induced increase in fat oxidation during exercise is likely related to alterations in skeletal muscle fatty acid metabolism.


2006 ◽  
Vol 38 (Supplement) ◽  
pp. S543
Author(s):  
Emma Fletcher ◽  
Fiona M. Sarsfield ◽  
Siomha Nee ◽  
Paul OʼConnor ◽  
Brendan Egan ◽  
...  

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