β2-agonists and running economy in prepubertal boys

Viswanath B. Unnithan, Kevin J. Thomson, Thomas C. Aitchison, James Y. Paton

Research output: Contribution to journalArticle

Abstract

Asthmatic athletes (adults and junior) have competed successfully at the highest level for many years assisted by pre-event medication with β2-agonists. To examine the impact of (β2–agonists upon submaximal running economy (oxygen consumption at a given submaximal work load), we studied 10 nonasthmatic boys (age, 10.4 ± 0.48 years, mean ± SD). They each completed submaximal (speeds, 7.2, 8.0, and 8.8 km/hr) and peak treadmill running protocols preceded by treatment with β2-agonist (terbutaline, 500 (μg via nebuhaler) or placebo in a randomized, crossover single-blind study. No significant differences were found between running economy and heart rate during the submaximal exercise tests or between peak oxygen consumption (V02), peak respiratory exchange ratio, peak heart rate (HR), or total running time during the peak V02 test. Pretreatment with terbutaline did produce small but nonsignificant increases in aerobic fractional utilization (percent peak V02 on drug: 65.9%, 72.6%, and 76.7% vs. placebo: 65.1%, 70%, and 75.5%), at the three submaximal work loads. Respiratory exchange ratio (RER) values were elevated throughout the submaximal tests (on drug: 0.94, 0.93, and 0.94 vs. placebo: 0.91, 0.92, and 0.91, P < 0.05). No significant differences were found between drug and placebo for minute ventilation (VE) and ventilatory equivalent for oxygen (VE/V02), at both submaximal and peak exercise intensities. The significant increase in forced expiratory volume in 1 second (FEV1) (% predicted) found following submaximal (pre: 107 ± 13 vs. post: 111 ± 17, P < 0.001) and peak exercise (pre: 103 ± 10 vs. post: 106 ± 14, P < 0.001), both with drug and placebo, suggests an effect of exercise rather than of drug. These results indicate that therapeutic doses of an inhaled β2–agonist administered immediately pre-exercise do not enhance the submaximal running economy or peak V02 of nonasthmatic children.
Original languageEnglish
Pages (from-to)378-382
Number of pages5
JournalPediatric Pulmonology
Volume17
Issue number6
DOIs
Publication statusPublished - Jun 1994
Externally publishedYes

Fingerprint

Placebos
Exercise
Terbutaline
Pharmaceutical Preparations
Workload
Oxygen Consumption
Ventilation
Heart Rate
Single-Blind Method
Placebo Effect
Forced Expiratory Volume
Clinical Protocols
Exercise Test
Running
Athletes
Oxygen
Therapeutics

Cite this

Unnithan, Viswanath B. ; Thomson, Kevin J. ; Aitchison, Thomas C. ; Paton, James Y. / β2-agonists and running economy in prepubertal boys. In: Pediatric Pulmonology. 1994 ; Vol. 17, No. 6. pp. 378-382.
@article{c0860ecc3139402082db4737d59247c4,
title = "β2-agonists and running economy in prepubertal boys",
abstract = "Asthmatic athletes (adults and junior) have competed successfully at the highest level for many years assisted by pre-event medication with β2-agonists. To examine the impact of (β2–agonists upon submaximal running economy (oxygen consumption at a given submaximal work load), we studied 10 nonasthmatic boys (age, 10.4 ± 0.48 years, mean ± SD). They each completed submaximal (speeds, 7.2, 8.0, and 8.8 km/hr) and peak treadmill running protocols preceded by treatment with β2-agonist (terbutaline, 500 (μg via nebuhaler) or placebo in a randomized, crossover single-blind study. No significant differences were found between running economy and heart rate during the submaximal exercise tests or between peak oxygen consumption (V02), peak respiratory exchange ratio, peak heart rate (HR), or total running time during the peak V02 test. Pretreatment with terbutaline did produce small but nonsignificant increases in aerobic fractional utilization (percent peak V02 on drug: 65.9{\%}, 72.6{\%}, and 76.7{\%} vs. placebo: 65.1{\%}, 70{\%}, and 75.5{\%}), at the three submaximal work loads. Respiratory exchange ratio (RER) values were elevated throughout the submaximal tests (on drug: 0.94, 0.93, and 0.94 vs. placebo: 0.91, 0.92, and 0.91, P < 0.05). No significant differences were found between drug and placebo for minute ventilation (VE) and ventilatory equivalent for oxygen (VE/V02), at both submaximal and peak exercise intensities. The significant increase in forced expiratory volume in 1 second (FEV1) ({\%} predicted) found following submaximal (pre: 107 ± 13 vs. post: 111 ± 17, P < 0.001) and peak exercise (pre: 103 ± 10 vs. post: 106 ± 14, P < 0.001), both with drug and placebo, suggests an effect of exercise rather than of drug. These results indicate that therapeutic doses of an inhaled β2–agonist administered immediately pre-exercise do not enhance the submaximal running economy or peak V02 of nonasthmatic children.",
author = "Unnithan, {Viswanath B.} and Thomson, {Kevin J.} and Aitchison, {Thomas C.} and Paton, {James Y.}",
year = "1994",
month = "6",
doi = "10.1002/ppul.1950170607",
language = "English",
volume = "17",
pages = "378--382",
journal = "Pediatric Pulmonology",
issn = "1099-0496",
publisher = "Wiley",
number = "6",

}

β2-agonists and running economy in prepubertal boys. / Unnithan, Viswanath B.; Thomson, Kevin J.; Aitchison, Thomas C.; Paton, James Y.

In: Pediatric Pulmonology, Vol. 17, No. 6, 06.1994, p. 378-382.

Research output: Contribution to journalArticle

TY - JOUR

T1 - β2-agonists and running economy in prepubertal boys

AU - Unnithan, Viswanath B.

AU - Thomson, Kevin J.

AU - Aitchison, Thomas C.

AU - Paton, James Y.

PY - 1994/6

Y1 - 1994/6

N2 - Asthmatic athletes (adults and junior) have competed successfully at the highest level for many years assisted by pre-event medication with β2-agonists. To examine the impact of (β2–agonists upon submaximal running economy (oxygen consumption at a given submaximal work load), we studied 10 nonasthmatic boys (age, 10.4 ± 0.48 years, mean ± SD). They each completed submaximal (speeds, 7.2, 8.0, and 8.8 km/hr) and peak treadmill running protocols preceded by treatment with β2-agonist (terbutaline, 500 (μg via nebuhaler) or placebo in a randomized, crossover single-blind study. No significant differences were found between running economy and heart rate during the submaximal exercise tests or between peak oxygen consumption (V02), peak respiratory exchange ratio, peak heart rate (HR), or total running time during the peak V02 test. Pretreatment with terbutaline did produce small but nonsignificant increases in aerobic fractional utilization (percent peak V02 on drug: 65.9%, 72.6%, and 76.7% vs. placebo: 65.1%, 70%, and 75.5%), at the three submaximal work loads. Respiratory exchange ratio (RER) values were elevated throughout the submaximal tests (on drug: 0.94, 0.93, and 0.94 vs. placebo: 0.91, 0.92, and 0.91, P < 0.05). No significant differences were found between drug and placebo for minute ventilation (VE) and ventilatory equivalent for oxygen (VE/V02), at both submaximal and peak exercise intensities. The significant increase in forced expiratory volume in 1 second (FEV1) (% predicted) found following submaximal (pre: 107 ± 13 vs. post: 111 ± 17, P < 0.001) and peak exercise (pre: 103 ± 10 vs. post: 106 ± 14, P < 0.001), both with drug and placebo, suggests an effect of exercise rather than of drug. These results indicate that therapeutic doses of an inhaled β2–agonist administered immediately pre-exercise do not enhance the submaximal running economy or peak V02 of nonasthmatic children.

AB - Asthmatic athletes (adults and junior) have competed successfully at the highest level for many years assisted by pre-event medication with β2-agonists. To examine the impact of (β2–agonists upon submaximal running economy (oxygen consumption at a given submaximal work load), we studied 10 nonasthmatic boys (age, 10.4 ± 0.48 years, mean ± SD). They each completed submaximal (speeds, 7.2, 8.0, and 8.8 km/hr) and peak treadmill running protocols preceded by treatment with β2-agonist (terbutaline, 500 (μg via nebuhaler) or placebo in a randomized, crossover single-blind study. No significant differences were found between running economy and heart rate during the submaximal exercise tests or between peak oxygen consumption (V02), peak respiratory exchange ratio, peak heart rate (HR), or total running time during the peak V02 test. Pretreatment with terbutaline did produce small but nonsignificant increases in aerobic fractional utilization (percent peak V02 on drug: 65.9%, 72.6%, and 76.7% vs. placebo: 65.1%, 70%, and 75.5%), at the three submaximal work loads. Respiratory exchange ratio (RER) values were elevated throughout the submaximal tests (on drug: 0.94, 0.93, and 0.94 vs. placebo: 0.91, 0.92, and 0.91, P < 0.05). No significant differences were found between drug and placebo for minute ventilation (VE) and ventilatory equivalent for oxygen (VE/V02), at both submaximal and peak exercise intensities. The significant increase in forced expiratory volume in 1 second (FEV1) (% predicted) found following submaximal (pre: 107 ± 13 vs. post: 111 ± 17, P < 0.001) and peak exercise (pre: 103 ± 10 vs. post: 106 ± 14, P < 0.001), both with drug and placebo, suggests an effect of exercise rather than of drug. These results indicate that therapeutic doses of an inhaled β2–agonist administered immediately pre-exercise do not enhance the submaximal running economy or peak V02 of nonasthmatic children.

U2 - 10.1002/ppul.1950170607

DO - 10.1002/ppul.1950170607

M3 - Article

VL - 17

SP - 378

EP - 382

JO - Pediatric Pulmonology

JF - Pediatric Pulmonology

SN - 1099-0496

IS - 6

ER -