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Correction to: Considerations in the Use of Body Mass Change to Estimate Change in Hydration Status During a 161-Kilometer Ultramarathon Running Competition

  • Martin D. Hoffman
  • Eric D. B. Goulet
  • Ronald J. Maughan
Correction
  • 54 Downloads

1 Correction to: Sports Med 2018;48(2):243–250  https://doi.org/10.1007/s40279-017-0782-3

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

Italicized text in the section outlining the conditions is used to show adjustments relative to the ‘average runner’. See text for support for the defined conditions for the ‘average runner’

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Department of Physical Medicine and Rehabilitation, Department of Veterans AffairsNorthern California Health Care SystemSacramentoUSA
  2. 2.Department of Physical Medicine and RehabilitationUniversity of California Davis Medical CenterSacramentoUSA
  3. 3.Ultra Sports Science FoundationEl Dorado HillsUSA
  4. 4.Research Centre on Aging and Faculty of Physical Activity SciencesUniversity of SherbrookeSherbrookeCanada
  5. 5.School of MedicineSt Andrews UniversitySt AndrewsUK

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