Boggs Greg W, Ward Jesse R, Stavrianeas Stasinos
Department of Exercise Science, Willamette University, Salem, Oregon, USA.
J Strength Cond Res. 2008 Jan;22(1):269-75. doi: 10.1519/JSC.0b013e31815f903e.
This study examined the effects of an external nasal dilator (END) on sedentary and aerobically trained women using the blood lactate threshold as a measure of aerobic performance. Three groups of women (sedentary, pre-season, in-season) participated in the study: nine sedentary college students (age 19 +/- 1.0 y), eight pre-season college athletes (age 20 +/- 2.3 y), and six in-season college rowers (age 20 +/- 1.7 y). A two-way repeated-measures design was used with subjects in each group being exposed to both conditions (with END and without END). The first two groups performed two incremental exercise tests in random order on a cycle ergometer, and the third group performed the tests on a rowing ergometer. Participants in each group wore an END strip for only one of the tests. Venous blood was collected at rest, during the final 30 seconds of each stage, and 1 and 3 minutes into the recovery period for the determination of blood lactate concentration and identification of the blood lactate threshold. No significant differences (P = 0.05) were found in blood lactate concentration at the lactate threshold between conditions for either group (sedentary: with END 2.51 +/- 1.18 mmol x L(-1), without END 2.56 +/- 0.84 mmol x L(-1); pre-season: with END 2.93 +/- 0.97 mmol x L(-1), without END 2.81 +/- 1.15 mmol x L(-1); and in-season: with END 3.93 +/- 0.50 mmol x L(-1), without END 3.49 +/- 0.387 mmol x L(-1)). We conclude that (a) the END did not improve the lactate threshold in either sedentary or trained college-age women, and (b) the END did not result in lower blood lactate levels during moderate to high-intensity exercise in the three groups examined in this study.
本研究以血乳酸阈值作为有氧能力的衡量指标，探讨了外部鼻扩张器（END）对久坐不动和进行有氧训练的女性的影响。三组女性（久坐不动组、赛季前组、赛季中组）参与了该研究：九名久坐不动的大学生（年龄19±1.0岁）、八名赛季前的大学运动员（年龄20±2.3岁）和六名赛季中的大学赛艇运动员（年龄20±1.7岁）。采用双向重复测量设计，每组受试者都要接受两种条件（使用END和不使用END）。前两组在自行车测力计上以随机顺序进行两次递增运动测试，第三组在赛艇测力计上进行测试。每组参与者仅在其中一次测试中佩戴END条。在静息状态、每个阶段的最后30秒以及恢复期的1分钟和3分钟时采集静脉血，以测定血乳酸浓度并确定血乳酸阈值。两组在各条件下的乳酸阈值时的血乳酸浓度均未发现显著差异（P = 0.05）（久坐不动组：使用END时为2.51±1.18 mmol·L⁻¹，不使用END时为2.56±0.84 mmol·L⁻¹；赛季前组：使用END时为2.93±0.97 mmol·L⁻¹，不使用END时为2.81±1.15 mmol·L⁻¹；赛季中组：使用END时为3.93±0.50 mmol·L⁻¹，不使用END时为3.49±0.387 mmol·L⁻¹）。我们得出结论：（a）END并未提高久坐不动或经过训练的大学适龄女性的乳酸阈值；（b）在本研究中所考察的三组中，END并未导致中高强度运动期间血乳酸水平降低。
