Abstract
Drinking ad libitum during exercise often leads to dehydration ranging from j1% to j3% of body weight. Purpose: This article aimed to study the effect of a prescribed hydration protocol matching fluid losses on a simulated 30-km criterium-like cycling performance in the heat (31.6-C T 0.5-C). Methods: Ten elite heat-acclimatized male endurance cyclists (30 T 5 yr, 76.5 T 7.2 kg, 1.81 T 0.07 m,V O2peak = 61.3 T 5.2 mLIminj1Ikgj1, body fat = 10.5% T 3.3%, Powermax = 392 T 33 W) performed three sets of criterium-like cycling, which consisted of a 5-km cycling at 50% power max followed by a 5-km cycling all out at 3% grade (total 30 km). Participants rode the course on two separate occasions and in a counterbalanced order, during either ad libitum drinking (AD; drink water as much as they wished) or prescribed drinking (PD; drink water every 1 km to much fluid losses). To design the fluid intake during PD, participants performed a familiarization trial to calculate fluid losses. Results: After the exercise protocol, the cyclist dehydrated by j0.5% T 0.3% and j1.8% T 0.7% of their body weight for the PD and AD trial, respectively. The mean cycling speed for the third bout of the 5-km hill cycling was greater in the PD trial (30.2 T 2.4 kmIhj1) compared with the AD trial (28.8 T 2.6 kmIhj1) by 5.1% T 4.8% (P G 0.05). Gastrointestinal, mean skin, and mean body temperatures immediately after the last hill climbing were greater in the AD compared with the PD trial (P G 0.05). Overall, sweat sensitivity during the three climbing bouts was lower in the AD (15.6 T 5.7 gIWj1Imj2) compared with the PD trial (22.8 T 3.4 gIWj1Imj2, P G 0.05). Conclusion: The data suggested that PD to match fluid losses during exercise in the heat provided a performance advantage because of lower thermoregulatory strain and greater sweating responses.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1244-1251 |
| Number of pages | 8 |
| Journal | Medicine and science in sports and exercise |
| Volume | 49 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jan 1 2017 |
| Externally published | Yes |
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Keywords
- Dehydration
- Fluid Balance
- Gastrointestinal Temperature
- Sweating
- Thermoregulation
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Prescribed drinking leads to better cycling performance than ad libitum drinking. / Bardis, Costas N.; Kavouras, Stavros A.; Adams, J. D.; Geladas, Nickos D.; Panagiotakos, Demosthenes B.; Sidossis, Labros S.
In: Medicine and science in sports and exercise, Vol. 49, No. 6, 01.01.2017, p. 1244-1251.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Prescribed drinking leads to better cycling performance than ad libitum drinking
AU - Bardis, Costas N.
AU - Kavouras, Stavros A.
AU - Adams, J. D.
AU - Geladas, Nickos D.
AU - Panagiotakos, Demosthenes B.
AU - Sidossis, Labros S.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Drinking ad libitum during exercise often leads to dehydration ranging from j1% to j3% of body weight. Purpose: This article aimed to study the effect of a prescribed hydration protocol matching fluid losses on a simulated 30-km criterium-like cycling performance in the heat (31.6-C T 0.5-C). Methods: Ten elite heat-acclimatized male endurance cyclists (30 T 5 yr, 76.5 T 7.2 kg, 1.81 T 0.07 m,V O2peak = 61.3 T 5.2 mLIminj1Ikgj1, body fat = 10.5% T 3.3%, Powermax = 392 T 33 W) performed three sets of criterium-like cycling, which consisted of a 5-km cycling at 50% power max followed by a 5-km cycling all out at 3% grade (total 30 km). Participants rode the course on two separate occasions and in a counterbalanced order, during either ad libitum drinking (AD; drink water as much as they wished) or prescribed drinking (PD; drink water every 1 km to much fluid losses). To design the fluid intake during PD, participants performed a familiarization trial to calculate fluid losses. Results: After the exercise protocol, the cyclist dehydrated by j0.5% T 0.3% and j1.8% T 0.7% of their body weight for the PD and AD trial, respectively. The mean cycling speed for the third bout of the 5-km hill cycling was greater in the PD trial (30.2 T 2.4 kmIhj1) compared with the AD trial (28.8 T 2.6 kmIhj1) by 5.1% T 4.8% (P G 0.05). Gastrointestinal, mean skin, and mean body temperatures immediately after the last hill climbing were greater in the AD compared with the PD trial (P G 0.05). Overall, sweat sensitivity during the three climbing bouts was lower in the AD (15.6 T 5.7 gIWj1Imj2) compared with the PD trial (22.8 T 3.4 gIWj1Imj2, P G 0.05). Conclusion: The data suggested that PD to match fluid losses during exercise in the heat provided a performance advantage because of lower thermoregulatory strain and greater sweating responses.
AB - Drinking ad libitum during exercise often leads to dehydration ranging from j1% to j3% of body weight. Purpose: This article aimed to study the effect of a prescribed hydration protocol matching fluid losses on a simulated 30-km criterium-like cycling performance in the heat (31.6-C T 0.5-C). Methods: Ten elite heat-acclimatized male endurance cyclists (30 T 5 yr, 76.5 T 7.2 kg, 1.81 T 0.07 m,V O2peak = 61.3 T 5.2 mLIminj1Ikgj1, body fat = 10.5% T 3.3%, Powermax = 392 T 33 W) performed three sets of criterium-like cycling, which consisted of a 5-km cycling at 50% power max followed by a 5-km cycling all out at 3% grade (total 30 km). Participants rode the course on two separate occasions and in a counterbalanced order, during either ad libitum drinking (AD; drink water as much as they wished) or prescribed drinking (PD; drink water every 1 km to much fluid losses). To design the fluid intake during PD, participants performed a familiarization trial to calculate fluid losses. Results: After the exercise protocol, the cyclist dehydrated by j0.5% T 0.3% and j1.8% T 0.7% of their body weight for the PD and AD trial, respectively. The mean cycling speed for the third bout of the 5-km hill cycling was greater in the PD trial (30.2 T 2.4 kmIhj1) compared with the AD trial (28.8 T 2.6 kmIhj1) by 5.1% T 4.8% (P G 0.05). Gastrointestinal, mean skin, and mean body temperatures immediately after the last hill climbing were greater in the AD compared with the PD trial (P G 0.05). Overall, sweat sensitivity during the three climbing bouts was lower in the AD (15.6 T 5.7 gIWj1Imj2) compared with the PD trial (22.8 T 3.4 gIWj1Imj2, P G 0.05). Conclusion: The data suggested that PD to match fluid losses during exercise in the heat provided a performance advantage because of lower thermoregulatory strain and greater sweating responses.
KW - Dehydration
KW - Fluid Balance
KW - Gastrointestinal Temperature
KW - Sweating
KW - Thermoregulation
UR - http://www.scopus.com/inward/record.url?scp=85009412394&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85009412394&partnerID=8YFLogxK
U2 - 10.1249/MSS.0000000000001202
DO - 10.1249/MSS.0000000000001202
M3 - Article
C2 - 28079705
AN - SCOPUS:85009412394
VL - 49
SP - 1244
EP - 1251
JO - Medicine and Science in Sports and Exercise
JF - Medicine and Science in Sports and Exercise
SN - 0195-9131
IS - 6
ER -