Alternate-day low energy availability during Spring Classics in professional cyclists
Journal article
Heikura, Ida A., Quod, Marc, Strobel, Nicki, Palfreeman, Roger, Civil, Rita and Burke, Louise. (2019). Alternate-day low energy availability during Spring Classics in professional cyclists. International Journal of Sports Physiology and Performance. 14(9), pp. 1233 - 1243. https://doi.org/10.1123/ijspp.2018-0842
Authors | Heikura, Ida A., Quod, Marc, Strobel, Nicki, Palfreeman, Roger, Civil, Rita and Burke, Louise |
---|---|
Abstract | Purpose: To assess energy and carbohydrate (CHO) availability and changes in blood hormones in 6 professional male cyclists over multiple single-day races. Methods: The authors collected weighed-food records, power-meter data, and morning body mass measurements across 8 d. CHO intakes were compared with contemporary guidelines. Energy availability (EA) was calculated as energy intake minus exercise energy expenditure, relative to fat-free mass (FFM). Skinfold thickness and blood metabolic and reproductive hormones were measured prestudy and poststudy. Statistical significance was defined as P ≤ .05. Results: Body mass (P = .11) or skinfold thickness (P = .75) did not change across time, despite alternate-day low EA (14 [9] vs 57 [10] kcal·kg−1 FFM·d−1, race vs rest days, respectively; P < .001). Cyclists with extremely low EA on race days (<10 kcal·kg−1 FFM·d−1; n = 2) experienced a trend toward decreased testosterone (−14%) and insulin-like growth factor 1 (−25%), despite being high EA (>46 kcal·kg−1 FFM·d−1) on days between. CHO intakes were significantly higher on race versus rest days (10.7 [1.3] vs 6.4 [0.8] g·kg−1·d−1, respectively; P < .001). The cyclists reached contemporary prerace fueling targets (3.4 [0.7] g·kg−1·3 h−1 CHO; P = .24), while the execution of CHO guidelines during race (51 [9] g·h−1; P = .048) and within acute (1.6 [0.5] g·kg−1·3 h−1; P = .002) and prolonged (7.4 [1.0] g·kg−1·24 h−1; P = .002) postrace recovery was poor. Conclusions: The authors are the first to report the day-by-day periodization of energy and CHO in a small sample of professional cyclists. They also examined the logistics of conducting a field study under stressful conditions in which major cooperation from the subjects and team management is needed. Their commentary around these challenges and possible solutions is a major novelty of the article. |
Keywords | professional cycling; nutrition periodization; hormones; single-day racing |
Year | 2019 |
Journal | International Journal of Sports Physiology and Performance |
Journal citation | 14 (9), pp. 1233 - 1243 |
Publisher | Human Kinetics, Inc. |
ISSN | 1555-0265 |
Digital Object Identifier (DOI) | https://doi.org/10.1123/ijspp.2018-0842 |
Scopus EID | 2-s2.0-85074940135 |
Open access | Published as green open access |
Page range | 1233 - 1243 |
Research Group | Mary MacKillop Institute for Health Research |
Author's accepted manuscript | License All rights reserved File Access Level Open |
Publisher's version | File Access Level Controlled |
Additional information | Accepted author manuscript version reprinted, by permission, from International Journal of Sports Physiology and Performance, 2019, 14(9): 1233–1243, https://www.doi.org/10.1123/ijspp.2018-0842 © Human Kinetics, Inc. |
Place of publication | United States of America |
https://acuresearchbank.acu.edu.au/item/866yy/alternate-day-low-energy-availability-during-spring-classics-in-professional-cyclists
Download files
Author's accepted manuscript
AM_Heikura_2019_Alternate_day_low_energy_availability_during.pdf | |
License: All rights reserved | |
File access level: Open |
Restricted files
Publisher's version
134
total views294
total downloads0
views this month0
downloads this month