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High cycling cadence reduces carbohydrate oxidation at given low intensity metabolic rate.

Beneke R, Alkhatib A - Biol Sport (2014)

Bottom Line: Aim of the present study was to test whether a higher RPM reduces the fraction (%) of the [Formula: see text]O2 used for carbohydrate oxidation (relCHO) at a given BLC.At 50 RPM, kCHO (4.2 ± 1.4 (mmol · l (-1))(3)) was lower (p = 0.043; η(2) = 0.466) than at 100 RPM (5.9 ± 1.9 (mmol · l (-1))(3)).This difference in kCHO reflects a reduced CHO oxidation at a given BLC at 100 than at 50 RPM.

View Article: PubMed Central - PubMed

Affiliation: Abt. Medizin, Training und Gesundheit, Inst. Sportwissenschaft und Motologie, Philipps Universität Marburg, Germany.

ABSTRACT
Cycling cadence (RPM)-related differences in blood lactate concentration (BLC) increase with increasing exercise intensity, whilst corresponding divergences in oxygen uptake ([Formula: see text]O2) and carbon dioxide production ([Formula: see text]CO2) decrease. Aim of the present study was to test whether a higher RPM reduces the fraction (%) of the [Formula: see text]O2 used for carbohydrate oxidation (relCHO) at a given BLC. Eight males (23.9 ± 1.6 yrs; 177 ± 3 cm; 70.3 ± 3.4 kg) performed incremental load tests at 50 and 100 RPM. BLC, [Formula: see text]O2 and [Formula: see text]CO2 were measured. At respiratory exchange ratios (RER) < 1, relCHO were calculated and the constant determining 50 % relCHO (kCHO) was approximated as a function of the BLC. At submaximal workload [Formula: see text]O2, [Formula: see text]CO2, and relCHO were lower (all p < 0.002; η(2) > 0.209) at 50 than at 100 RPM. No differences were observed in [Formula: see text]O2peak (3.96 ± 0.22 vs. 4.00 ± 0.25 l · min (-1)) and RERpeak (1.18 ± 0.02 vs. 1.15 ± 0.02). BLC was lower (p < 0.001; η(2) = 0.680) at 50 than at 100 RPM irrespective of cycling intensity. At 50 RPM, kCHO (4.2 ± 1.4 (mmol · l (-1))(3)) was lower (p = 0.043; η(2) = 0.466) than at 100 RPM (5.9 ± 1.9 (mmol · l (-1))(3)). This difference in kCHO reflects a reduced CHO oxidation at a given BLC at 100 than at 50 RPM. At a low exercise intensity, a higher cycling cadence can substantially reduce the reliance on CHO at a given metabolic rate and/or BLC.

No MeSH data available.


Blood lactate concentration (BLC) and relative carbohydrate oxidation (relCHO) at 50 RPM (● and ○) and at 100 RPM (■ and □); mean ± SE; * = difference between 50 and 100 RPM (all p < 0.05).
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Figure 0003: Blood lactate concentration (BLC) and relative carbohydrate oxidation (relCHO) at 50 RPM (● and ○) and at 100 RPM (■ and □); mean ± SE; * = difference between 50 and 100 RPM (all p < 0.05).

Mentions: The BLC was lower (p < 0.001) at 50 RPM than at 100 RPM irrespective of workload (Fig. 3). A corresponding effect on relCHO was seen up to a workload of 2.0 W · kg−1 (Fig. 3), which was equivalent to BLC levels of 1.8 ± 0.2 mmol · l−1 vs. 2.7 ± 0.3 mmol · l−1 (p = 0.003; η2 = 0.745), and IntVO2 of 51.6 ± 1.4 % vs. 60.5 ± 2.5 % (p < 0.01), whilst IntP of 47.5 ± 1.8 % vs. 48.4 ± 2.3 % (n.s.) were not different at 50 and 100 RPM. At the individually highest workload (2.9 ± 0.2 W · kg−1 vs. 2.8 ± 0.3 W · kg−1; n.s.) with an RER < 1.0 (0.97 ± 0.01 vs. 0.99 ± 0.01; n.s.), the BLC was lower (2.9 ± 0.3 mmol · l−1 vs. 4.0 ± 0.3 mmol · l−1; p = 0.009; η2 = 0.651) at 50 RPM than at 100 RPM but not IntP (68.6 ± 2.4 % vs. 64.5 ± 3.4 %; n.s.) and IntVO2 (71.4 ± 3.0 % vs. 74.0 ± 3.0 %; n.s.) or relCHO (89.5 ± 1.9 % vs. 95.1 ± 1.2 %; n.s.).


High cycling cadence reduces carbohydrate oxidation at given low intensity metabolic rate.

Beneke R, Alkhatib A - Biol Sport (2014)

Blood lactate concentration (BLC) and relative carbohydrate oxidation (relCHO) at 50 RPM (● and ○) and at 100 RPM (■ and □); mean ± SE; * = difference between 50 and 100 RPM (all p < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4314601&req=5

Figure 0003: Blood lactate concentration (BLC) and relative carbohydrate oxidation (relCHO) at 50 RPM (● and ○) and at 100 RPM (■ and □); mean ± SE; * = difference between 50 and 100 RPM (all p < 0.05).
Mentions: The BLC was lower (p < 0.001) at 50 RPM than at 100 RPM irrespective of workload (Fig. 3). A corresponding effect on relCHO was seen up to a workload of 2.0 W · kg−1 (Fig. 3), which was equivalent to BLC levels of 1.8 ± 0.2 mmol · l−1 vs. 2.7 ± 0.3 mmol · l−1 (p = 0.003; η2 = 0.745), and IntVO2 of 51.6 ± 1.4 % vs. 60.5 ± 2.5 % (p < 0.01), whilst IntP of 47.5 ± 1.8 % vs. 48.4 ± 2.3 % (n.s.) were not different at 50 and 100 RPM. At the individually highest workload (2.9 ± 0.2 W · kg−1 vs. 2.8 ± 0.3 W · kg−1; n.s.) with an RER < 1.0 (0.97 ± 0.01 vs. 0.99 ± 0.01; n.s.), the BLC was lower (2.9 ± 0.3 mmol · l−1 vs. 4.0 ± 0.3 mmol · l−1; p = 0.009; η2 = 0.651) at 50 RPM than at 100 RPM but not IntP (68.6 ± 2.4 % vs. 64.5 ± 3.4 %; n.s.) and IntVO2 (71.4 ± 3.0 % vs. 74.0 ± 3.0 %; n.s.) or relCHO (89.5 ± 1.9 % vs. 95.1 ± 1.2 %; n.s.).

Bottom Line: Aim of the present study was to test whether a higher RPM reduces the fraction (%) of the [Formula: see text]O2 used for carbohydrate oxidation (relCHO) at a given BLC.At 50 RPM, kCHO (4.2 ± 1.4 (mmol · l (-1))(3)) was lower (p = 0.043; η(2) = 0.466) than at 100 RPM (5.9 ± 1.9 (mmol · l (-1))(3)).This difference in kCHO reflects a reduced CHO oxidation at a given BLC at 100 than at 50 RPM.

View Article: PubMed Central - PubMed

Affiliation: Abt. Medizin, Training und Gesundheit, Inst. Sportwissenschaft und Motologie, Philipps Universität Marburg, Germany.

ABSTRACT
Cycling cadence (RPM)-related differences in blood lactate concentration (BLC) increase with increasing exercise intensity, whilst corresponding divergences in oxygen uptake ([Formula: see text]O2) and carbon dioxide production ([Formula: see text]CO2) decrease. Aim of the present study was to test whether a higher RPM reduces the fraction (%) of the [Formula: see text]O2 used for carbohydrate oxidation (relCHO) at a given BLC. Eight males (23.9 ± 1.6 yrs; 177 ± 3 cm; 70.3 ± 3.4 kg) performed incremental load tests at 50 and 100 RPM. BLC, [Formula: see text]O2 and [Formula: see text]CO2 were measured. At respiratory exchange ratios (RER) < 1, relCHO were calculated and the constant determining 50 % relCHO (kCHO) was approximated as a function of the BLC. At submaximal workload [Formula: see text]O2, [Formula: see text]CO2, and relCHO were lower (all p < 0.002; η(2) > 0.209) at 50 than at 100 RPM. No differences were observed in [Formula: see text]O2peak (3.96 ± 0.22 vs. 4.00 ± 0.25 l · min (-1)) and RERpeak (1.18 ± 0.02 vs. 1.15 ± 0.02). BLC was lower (p < 0.001; η(2) = 0.680) at 50 than at 100 RPM irrespective of cycling intensity. At 50 RPM, kCHO (4.2 ± 1.4 (mmol · l (-1))(3)) was lower (p = 0.043; η(2) = 0.466) than at 100 RPM (5.9 ± 1.9 (mmol · l (-1))(3)). This difference in kCHO reflects a reduced CHO oxidation at a given BLC at 100 than at 50 RPM. At a low exercise intensity, a higher cycling cadence can substantially reduce the reliance on CHO at a given metabolic rate and/or BLC.

No MeSH data available.