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The Respiratory Exchange Ratio is Associated with Fitness Indicators Both in Trained and Untrained Men: A Possible Application for People with Reduced Exercise Tolerance.

Ramos-Jiménez A, Hernández-Torres RP, Torres-Durán PV, Romero-Gonzalez J, Mascher D, Posadas-Romero C, Juárez-Oropeza MA - Clin Med Circ Respirat Pulm Med (2008)

Bottom Line: The respiratory exchange ratio (RER) indirectly shows the muscle's oxidative capacity to get energy.Endurance trained men presented higher O(2) uptake, lower blood lactate concentrations and lower RER values than those in untrained men at the three similar relative workloads.Furthermore, the results suggest that RER could help obtain an easy approach of fitness status under low exercise intensity and could be utilized in subjects with reduced exercise tolerance.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Science, Biomedical Science Institute, UACJ, Cd. Juarez Chih, Mexico.

ABSTRACT

Background: The respiratory exchange ratio (RER) indirectly shows the muscle's oxidative capacity to get energy. Sedentarism, exercise and physically active lifestyles modify it. For that reason, this study evaluates the associations between RER during sub-maximum exercise and other well established fitness indicators (body fat, maximum heart rate, maximum O(2) uptake, workload, and lactate threshold), in physically active trained and untrained men.

Methods: The RER, O(2) uptake and blood lactate were measured in eight endurance trained and eight untrained men (age, 22.9 ± 4.5 vs. 21.9 ± 2.8 years; body mass, 67.1 ± 5.4 vs. 72.2 ± 7.7 kg; body fat, 10.6 ± 2.4% vs. 16.6 ± 3.8% and maximum O(2) uptake, 68.9 ± 6.3 vs. 51.6 ± 5.8 ml•kg(-1)•min(-1)), during maximum exercise test and during three different sub-maximum exercises at fixed workload: below, within or above the lactate threshold.

Results: Endurance trained men presented higher O(2) uptake, lower blood lactate concentrations and lower RER values than those in untrained men at the three similar relative workloads. Even though with these differences in RER, a strong association (p < 0.05) of RER during sub-maximum exercise with the other well established fitness indicators was observed, and both maximum O(2) uptake and lactate threshold determined more than 57% of its variance (p < 0.05).

Conclusions: These data demonstrate that RER measurement under sub-maximum exercise conditions was well correlated with other established physical fitness indicators, despite training condition. Furthermore, the results suggest that RER could help obtain an easy approach of fitness status under low exercise intensity and could be utilized in subjects with reduced exercise tolerance.

No MeSH data available.


Related in: MedlinePlus

Respiratory exchange ratio (RER) values during submaximal exercises in endurance trained and untrained men. Open circles, untrained subjects; solid circles, trained subjects. The tests durations were 4.0, 6.3 and 30.0 min for above LT, within LT and below LT, respectively. LT: lactate threshold. RER values are means of one minute taken at the initiation of exercise (1), at the middle of the test (2) and at the end of the test (3). Data are expressed as mean ± SEM, n = 8.
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f3-ccrpm-2008-001: Respiratory exchange ratio (RER) values during submaximal exercises in endurance trained and untrained men. Open circles, untrained subjects; solid circles, trained subjects. The tests durations were 4.0, 6.3 and 30.0 min for above LT, within LT and below LT, respectively. LT: lactate threshold. RER values are means of one minute taken at the initiation of exercise (1), at the middle of the test (2) and at the end of the test (3). Data are expressed as mean ± SEM, n = 8.

Mentions: As expected, all the physical fitness variables: body fat, VO2max, workloadmax and lactate threshold (measured as watts and VO2) were significantly different in trained subjects compared to untrained (Table 1). No differences in food intake and percentage of macronutrients composition were observed between the groups (Table 2). Although the trained subjects were working at higher workload intensity (Table 3) and VO2 at any SEFW, lower lactate concentrations and lower RER values were observed in them compared to those in untrained subjects (Fig. 1–3).


The Respiratory Exchange Ratio is Associated with Fitness Indicators Both in Trained and Untrained Men: A Possible Application for People with Reduced Exercise Tolerance.

Ramos-Jiménez A, Hernández-Torres RP, Torres-Durán PV, Romero-Gonzalez J, Mascher D, Posadas-Romero C, Juárez-Oropeza MA - Clin Med Circ Respirat Pulm Med (2008)

Respiratory exchange ratio (RER) values during submaximal exercises in endurance trained and untrained men. Open circles, untrained subjects; solid circles, trained subjects. The tests durations were 4.0, 6.3 and 30.0 min for above LT, within LT and below LT, respectively. LT: lactate threshold. RER values are means of one minute taken at the initiation of exercise (1), at the middle of the test (2) and at the end of the test (3). Data are expressed as mean ± SEM, n = 8.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2990231&req=5

f3-ccrpm-2008-001: Respiratory exchange ratio (RER) values during submaximal exercises in endurance trained and untrained men. Open circles, untrained subjects; solid circles, trained subjects. The tests durations were 4.0, 6.3 and 30.0 min for above LT, within LT and below LT, respectively. LT: lactate threshold. RER values are means of one minute taken at the initiation of exercise (1), at the middle of the test (2) and at the end of the test (3). Data are expressed as mean ± SEM, n = 8.
Mentions: As expected, all the physical fitness variables: body fat, VO2max, workloadmax and lactate threshold (measured as watts and VO2) were significantly different in trained subjects compared to untrained (Table 1). No differences in food intake and percentage of macronutrients composition were observed between the groups (Table 2). Although the trained subjects were working at higher workload intensity (Table 3) and VO2 at any SEFW, lower lactate concentrations and lower RER values were observed in them compared to those in untrained subjects (Fig. 1–3).

Bottom Line: The respiratory exchange ratio (RER) indirectly shows the muscle's oxidative capacity to get energy.Endurance trained men presented higher O(2) uptake, lower blood lactate concentrations and lower RER values than those in untrained men at the three similar relative workloads.Furthermore, the results suggest that RER could help obtain an easy approach of fitness status under low exercise intensity and could be utilized in subjects with reduced exercise tolerance.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Science, Biomedical Science Institute, UACJ, Cd. Juarez Chih, Mexico.

ABSTRACT

Background: The respiratory exchange ratio (RER) indirectly shows the muscle's oxidative capacity to get energy. Sedentarism, exercise and physically active lifestyles modify it. For that reason, this study evaluates the associations between RER during sub-maximum exercise and other well established fitness indicators (body fat, maximum heart rate, maximum O(2) uptake, workload, and lactate threshold), in physically active trained and untrained men.

Methods: The RER, O(2) uptake and blood lactate were measured in eight endurance trained and eight untrained men (age, 22.9 ± 4.5 vs. 21.9 ± 2.8 years; body mass, 67.1 ± 5.4 vs. 72.2 ± 7.7 kg; body fat, 10.6 ± 2.4% vs. 16.6 ± 3.8% and maximum O(2) uptake, 68.9 ± 6.3 vs. 51.6 ± 5.8 ml•kg(-1)•min(-1)), during maximum exercise test and during three different sub-maximum exercises at fixed workload: below, within or above the lactate threshold.

Results: Endurance trained men presented higher O(2) uptake, lower blood lactate concentrations and lower RER values than those in untrained men at the three similar relative workloads. Even though with these differences in RER, a strong association (p < 0.05) of RER during sub-maximum exercise with the other well established fitness indicators was observed, and both maximum O(2) uptake and lactate threshold determined more than 57% of its variance (p < 0.05).

Conclusions: These data demonstrate that RER measurement under sub-maximum exercise conditions was well correlated with other established physical fitness indicators, despite training condition. Furthermore, the results suggest that RER could help obtain an easy approach of fitness status under low exercise intensity and could be utilized in subjects with reduced exercise tolerance.

No MeSH data available.


Related in: MedlinePlus