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Erschienen in:
11.10.2018 | Correction
Correction to: Considerations in the Use of Body Mass Change to Estimate Change in Hydration Status During a 161-Kilometer Ultramarathon Running Competition
Erschienen in: Sports Medicine | Ausgabe 12/2018
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In Table 2 of the original publication, an error was made in the calculations for endogenous substrate oxidation which, subsequently, altered the values for total change in body mass. A corrected version of Table 2 is provided below. With the revised calculations, our conclusions are adjusted to indicate that the percentage of body mass loss required to sustain body water balance to maintain euhydration during an ~ 25–30 h 161-km mountain ultramarathon is 3.0% (rather than 4.2% as originally stated) for the ‘average runner’ and 1.2–3.5% (rather than 1.9–5.0% as originally stated) across a variety of other realistic assumptions. While the magnitude of the effect is slightly less with the corrected calculations, the key message that “universal guidelines to avoid body mass loss over 2% during exercise are not suitable to circumstances when the exercise is prolonged running of several hours” is unchanged.
Table 2
Required change in body mass to sustain body water balance to maintain euhydration during a 161-km mountain ultramarathon under various conditions
|
Average runner
|
10% of energy derived from protein
|
67% less water linked with glycogen
|
25% less glycogen
|
25% more glycogen
|
30% more calories consumed
|
30% less calories consumed
|
Less water linked with glycogen + less glycogen + more calories consumed
|
|
|---|---|---|---|---|---|---|---|---|
|
Conditions
|
||||||||
|
Energy cost (kcal)
|
14,500
|
14,500
|
14,500
|
14,500
|
14,500
|
14,500
|
14,500
|
14,500
|
|
Exogenous energy (kcal)
|
8228
|
8228
|
8228
|
8228
|
8228
|
10,696
|
5760
|
10,696
|
|
Carbohydrate (%)
|
81.5
|
81.5
|
81.5
|
81.5
|
81.5
|
81.5
|
81.5
|
81.5
|
|
Fat (%)
|
11.9
|
11.9
|
11.9
|
11.9
|
11.9
|
11.9
|
11.9
|
11.9
|
|
Protein (%)
|
6.6
|
6.6
|
6.6
|
6.6
|
6.6
|
6.6
|
6.6
|
6.6
|
|
Pre-race body mass (kg)
|
68.8
|
68.8
|
68.8
|
68.8
|
68.8
|
68.8
|
68.8
|
68.8
|
|
Endogenous glycogen used (kg)
|
0.400
|
0.400
|
0.400
|
0.300
|
0.500
|
0.400
|
0.400
|
0.300
|
|
Water released per g of glycogen (g)
|
3
|
3
|
1
|
3
|
3
|
3
|
3
|
1
|
|
Energy derived from protein (%)
|
5
|
10
|
5
|
5
|
5
|
5
|
5
|
5
|
|
Accumulated peripheral edema (kg)
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
|
Contributions to body mass change
|
||||||||
|
Endogenous substrate oxidation (kg)
|
||||||||
|
Carbohydrate
|
− 0.160
|
− 0.160
|
− 0.160
|
− 0.120
|
− 0.200
|
− 0.160
|
− 0.160
|
− 0.120
|
|
Fat
|
0.062
|
0.052
|
0.062
|
0.068
|
0.056
|
0.030
|
0.094
|
0.036
|
|
Protein
|
− 0.020
|
− 0.100
|
− 0.020
|
− 0.020
|
− 0.020
|
− 0.002
|
− 0.038
|
− 0.002
|
|
Water release from glycogen (kg)
|
− 1.200
|
− 1.200
|
− 0.400
|
− 0.900
|
− 1.500
|
− 1.200
|
− 1.200
|
− 0.300
|
|
Water of oxidation (kg)
|
||||||||
|
Carbohydrate
|
− 0.240
|
− 0.240
|
− 0.240
|
− 0.180
|
− 0.300
|
− 0.240
|
− 0.240
|
− 0.180
|
|
Fat
|
− 0.541
|
− 0.453
|
− 0.541
|
− 0.591
|
− 0.491
|
− 0.261
|
− 0.821
|
− 0.310
|
|
Protein
|
− 0.017
|
− 0.086
|
− 0.017
|
− 0.017
|
− 0.017
|
− 0.002
|
− 0.033
|
− 0.002
|
|
Accumulated peripheral edema (kg)
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
0.040
|
|
Total change in body mass
|
||||||||
|
Absolute (kg)
|
− 2.1
|
− 2.1
|
− 1.3
|
− 1.7
|
− 2.4
|
− 1.8
|
− 2.4
|
− 0.8
|
|
Relative to pre-race (%)
|
− 3.0
|
− 3.1
|
− 1.9
|
− 2.5
|
− 3.5
|
− 2.6
|
− 3.4
|
− 1.2
|