Carbohydrate supplementation and endurance performance of moderate altitude residents at 4300 m

Charles S. Fulco, M. Zupan, S. R. Muza, P. B. Rock, K. Kambis, T. Payn, M. Hannon, E. Glickman, A. Cymerman

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Recent work from our laboratory demonstrated that carbohydrate supplementation (CHOS) during exercise improved prolonged time-trial (TT) performance of sea-level residents (SLR) living at 4300 m while they were in daily negative energy balance (-1250 kcal·day-1; [9]). The purposes of the current study were to determine during initial exposure to 4300 m:1) whether CHOS also improves TT performance of moderate altitude residents (MAR) who are in energy balance and 2) if acclimatization to moderate elevations benefits TT performance. Fifteen Air Force Academy (AFA) active duty members (age: 30 ± 1 yrs; mean ± SE), who had been living at ∼2000 m for 21 ± 3 months performed a maximal-effort 720-kJ cycle TT at the AFA and at Pikes Peak (PP), CO, (4300 m) on days 1 (PP1) and 3 (PP3). Daily energy intake and expenditure were maintained similarly at the AFA and PP. At the start of the TTs at PP, and then every 15 min thereafter, 9 subjects drank a 10% CHO solution (0.175 g·kg-1 body weight) and 6 subjects drank a placebo (PLA) solution. All subjects were allowed to freely adjust the power output of the cycle ergometer and drank water ad libitum. Performance time did not differ between groups on PP1 (CHOS vs. PLA; 101 ± 8 vs. 116 ± 10 min) or PP3 (95 ± 8 vs. 107 ± 12 min). For both groups, cycle times on PP1 and PP3 were longer compared to the AFA (p < 0.01) and were improved from PP1 to PP3 (p < 0.05). Exercise intensity (i.e., % peak oxygen uptake) was maintained similarly at ∼62% during the TTs at the AFA and PP. Blood glucose was 1.5 to 2.0 mmol·L-1 higher for CHOS vs. PLA (p < 0.01). It was concluded that CHOS provided no TT performance benefit for MAR at 4300 m when energy balance was maintained. However, the decrements in TT performance and exercise intensity were attenuated at 4300 m in MAR compared to those of SLR as a result of acclimatization attained while living for nearly 2 years at ∼2000 m.

Original languageEnglish
Pages (from-to)437-443
Number of pages7
JournalInternational Journal of Sports Medicine
Volume28
Issue number5
DOIs
StatePublished - 1 May 2007

Fingerprint

Carbohydrates
Esocidae
Air
Acclimatization
Placebos
Oceans and Seas
Carbon Monoxide
Energy Intake
Energy Metabolism
Blood Glucose
Body Weight
Oxygen
Water

Keywords

  • Acclimatization
  • Altitude
  • Exercise performance
  • Time trial

Cite this

Fulco, Charles S. ; Zupan, M. ; Muza, S. R. ; Rock, P. B. ; Kambis, K. ; Payn, T. ; Hannon, M. ; Glickman, E. ; Cymerman, A. / Carbohydrate supplementation and endurance performance of moderate altitude residents at 4300 m. In: International Journal of Sports Medicine. 2007 ; Vol. 28, No. 5. pp. 437-443.
@article{e1fea99d17784675be46849c8a36c578,
title = "Carbohydrate supplementation and endurance performance of moderate altitude residents at 4300 m",
abstract = "Recent work from our laboratory demonstrated that carbohydrate supplementation (CHOS) during exercise improved prolonged time-trial (TT) performance of sea-level residents (SLR) living at 4300 m while they were in daily negative energy balance (-1250 kcal·day-1; [9]). The purposes of the current study were to determine during initial exposure to 4300 m:1) whether CHOS also improves TT performance of moderate altitude residents (MAR) who are in energy balance and 2) if acclimatization to moderate elevations benefits TT performance. Fifteen Air Force Academy (AFA) active duty members (age: 30 ± 1 yrs; mean ± SE), who had been living at ∼2000 m for 21 ± 3 months performed a maximal-effort 720-kJ cycle TT at the AFA and at Pikes Peak (PP), CO, (4300 m) on days 1 (PP1) and 3 (PP3). Daily energy intake and expenditure were maintained similarly at the AFA and PP. At the start of the TTs at PP, and then every 15 min thereafter, 9 subjects drank a 10{\%} CHO solution (0.175 g·kg-1 body weight) and 6 subjects drank a placebo (PLA) solution. All subjects were allowed to freely adjust the power output of the cycle ergometer and drank water ad libitum. Performance time did not differ between groups on PP1 (CHOS vs. PLA; 101 ± 8 vs. 116 ± 10 min) or PP3 (95 ± 8 vs. 107 ± 12 min). For both groups, cycle times on PP1 and PP3 were longer compared to the AFA (p < 0.01) and were improved from PP1 to PP3 (p < 0.05). Exercise intensity (i.e., {\%} peak oxygen uptake) was maintained similarly at ∼62{\%} during the TTs at the AFA and PP. Blood glucose was 1.5 to 2.0 mmol·L-1 higher for CHOS vs. PLA (p < 0.01). It was concluded that CHOS provided no TT performance benefit for MAR at 4300 m when energy balance was maintained. However, the decrements in TT performance and exercise intensity were attenuated at 4300 m in MAR compared to those of SLR as a result of acclimatization attained while living for nearly 2 years at ∼2000 m.",
keywords = "Acclimatization, Altitude, Exercise performance, Time trial",
author = "Fulco, {Charles S.} and M. Zupan and Muza, {S. R.} and Rock, {P. B.} and K. Kambis and T. Payn and M. Hannon and E. Glickman and A. Cymerman",
year = "2007",
month = "5",
day = "1",
doi = "10.1055/s-2006-924515",
language = "English",
volume = "28",
pages = "437--443",
journal = "International Journal of Sports Medicine",
issn = "0172-4622",
publisher = "Georg Thieme Verlag",
number = "5",

}

Fulco, CS, Zupan, M, Muza, SR, Rock, PB, Kambis, K, Payn, T, Hannon, M, Glickman, E & Cymerman, A 2007, 'Carbohydrate supplementation and endurance performance of moderate altitude residents at 4300 m', International Journal of Sports Medicine, vol. 28, no. 5, pp. 437-443. https://doi.org/10.1055/s-2006-924515

Carbohydrate supplementation and endurance performance of moderate altitude residents at 4300 m. / Fulco, Charles S.; Zupan, M.; Muza, S. R.; Rock, P. B.; Kambis, K.; Payn, T.; Hannon, M.; Glickman, E.; Cymerman, A.

In: International Journal of Sports Medicine, Vol. 28, No. 5, 01.05.2007, p. 437-443.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Carbohydrate supplementation and endurance performance of moderate altitude residents at 4300 m

AU - Fulco, Charles S.

AU - Zupan, M.

AU - Muza, S. R.

AU - Rock, P. B.

AU - Kambis, K.

AU - Payn, T.

AU - Hannon, M.

AU - Glickman, E.

AU - Cymerman, A.

PY - 2007/5/1

Y1 - 2007/5/1

N2 - Recent work from our laboratory demonstrated that carbohydrate supplementation (CHOS) during exercise improved prolonged time-trial (TT) performance of sea-level residents (SLR) living at 4300 m while they were in daily negative energy balance (-1250 kcal·day-1; [9]). The purposes of the current study were to determine during initial exposure to 4300 m:1) whether CHOS also improves TT performance of moderate altitude residents (MAR) who are in energy balance and 2) if acclimatization to moderate elevations benefits TT performance. Fifteen Air Force Academy (AFA) active duty members (age: 30 ± 1 yrs; mean ± SE), who had been living at ∼2000 m for 21 ± 3 months performed a maximal-effort 720-kJ cycle TT at the AFA and at Pikes Peak (PP), CO, (4300 m) on days 1 (PP1) and 3 (PP3). Daily energy intake and expenditure were maintained similarly at the AFA and PP. At the start of the TTs at PP, and then every 15 min thereafter, 9 subjects drank a 10% CHO solution (0.175 g·kg-1 body weight) and 6 subjects drank a placebo (PLA) solution. All subjects were allowed to freely adjust the power output of the cycle ergometer and drank water ad libitum. Performance time did not differ between groups on PP1 (CHOS vs. PLA; 101 ± 8 vs. 116 ± 10 min) or PP3 (95 ± 8 vs. 107 ± 12 min). For both groups, cycle times on PP1 and PP3 were longer compared to the AFA (p < 0.01) and were improved from PP1 to PP3 (p < 0.05). Exercise intensity (i.e., % peak oxygen uptake) was maintained similarly at ∼62% during the TTs at the AFA and PP. Blood glucose was 1.5 to 2.0 mmol·L-1 higher for CHOS vs. PLA (p < 0.01). It was concluded that CHOS provided no TT performance benefit for MAR at 4300 m when energy balance was maintained. However, the decrements in TT performance and exercise intensity were attenuated at 4300 m in MAR compared to those of SLR as a result of acclimatization attained while living for nearly 2 years at ∼2000 m.

AB - Recent work from our laboratory demonstrated that carbohydrate supplementation (CHOS) during exercise improved prolonged time-trial (TT) performance of sea-level residents (SLR) living at 4300 m while they were in daily negative energy balance (-1250 kcal·day-1; [9]). The purposes of the current study were to determine during initial exposure to 4300 m:1) whether CHOS also improves TT performance of moderate altitude residents (MAR) who are in energy balance and 2) if acclimatization to moderate elevations benefits TT performance. Fifteen Air Force Academy (AFA) active duty members (age: 30 ± 1 yrs; mean ± SE), who had been living at ∼2000 m for 21 ± 3 months performed a maximal-effort 720-kJ cycle TT at the AFA and at Pikes Peak (PP), CO, (4300 m) on days 1 (PP1) and 3 (PP3). Daily energy intake and expenditure were maintained similarly at the AFA and PP. At the start of the TTs at PP, and then every 15 min thereafter, 9 subjects drank a 10% CHO solution (0.175 g·kg-1 body weight) and 6 subjects drank a placebo (PLA) solution. All subjects were allowed to freely adjust the power output of the cycle ergometer and drank water ad libitum. Performance time did not differ between groups on PP1 (CHOS vs. PLA; 101 ± 8 vs. 116 ± 10 min) or PP3 (95 ± 8 vs. 107 ± 12 min). For both groups, cycle times on PP1 and PP3 were longer compared to the AFA (p < 0.01) and were improved from PP1 to PP3 (p < 0.05). Exercise intensity (i.e., % peak oxygen uptake) was maintained similarly at ∼62% during the TTs at the AFA and PP. Blood glucose was 1.5 to 2.0 mmol·L-1 higher for CHOS vs. PLA (p < 0.01). It was concluded that CHOS provided no TT performance benefit for MAR at 4300 m when energy balance was maintained. However, the decrements in TT performance and exercise intensity were attenuated at 4300 m in MAR compared to those of SLR as a result of acclimatization attained while living for nearly 2 years at ∼2000 m.

KW - Acclimatization

KW - Altitude

KW - Exercise performance

KW - Time trial

UR - http://www.scopus.com/inward/record.url?scp=34248584688&partnerID=8YFLogxK

U2 - 10.1055/s-2006-924515

DO - 10.1055/s-2006-924515

M3 - Article

C2 - 17024646

AN - SCOPUS:34248584688

VL - 28

SP - 437

EP - 443

JO - International Journal of Sports Medicine

JF - International Journal of Sports Medicine

SN - 0172-4622

IS - 5

ER -