ﺗﻐﯿﯿﺮات آﺳﺘﺎﻧﻪ ﺑﯽ ﻫﻮازي در ﻓﺎزﻫﺎي ﻣﺨﺘﻠﻒ ﭼﺮﺧﻪ ﻗﺎﻋﺪﮔﯽ: ﺗﺎﺛﯿﺮ اﻧﺘﺨﺎب ﺳﻮﺑﺴﺘﺮاي ﻣﺼﺮﻓﯽ

Anaerobic Threshold Variations during Different Phases of Menstrual Cycle: Effect of Substrate Selection

ﺳﺎﺑﻘﻪ و ﻫﺪف: ﻧﻮﺳﺎﻧﺎت ﻫﻮرﻣﻮﻧﯽ ﭼﺮﺧﻪ ﻗﺎﻋﺪﮔﯽ ﻣﻌﻤﻮﻻ ﺑﺎ ﺗﻐﯿﯿﺮ در ﻋﻤﻠﮑﺮد ورزﺷﯽ ﻫﻤﺮاه اﺳﺖ. ﻫﺪف از ﺗﺤﻘﯿﻖ ﺣﺎﺿﺮ، ﻣﻄﺎﻟﻌﻪ ﺗﺄﺛﯿﺮ ﻣﺮاﺣﻞ ﻣﺨﺘﻠﻒ ﭼﺮﺧﻪ ﻗﺎﻋﺪﮔﯽ ﺑﺮ ﻋﻤﻠﮑﺮد ﻫﻮازي، اﻧﺘﺨﺎب ﺳﻮﺑﺴﺘﺮاي ﻣﺼﺮﻓﯽ و ﺷﺎﺧﺼﻬﺎي ﻓﯿﺰﯾﻮﻟﻮژﯾﮑﯽ ﻣﻌﺎدل ﺑﺎ آﺳﺘﺎﻧﻪ ﺑﯽ ﻫﻮازي در زﻧﺎن ﻓﻌﺎل ﺷﻬﺮ ﮐﺮﻣﺎن ﺑﻮد. ﻣﻮاد و روﺷﻬﺎ: دوازده زن ﻓﻌﺎل ﺑﺎ ﭼﺮﺧﻪ ﻗﺎﻋﺪﮔﯽ ﻣﻨﻈﻢ در ﺗﺤﻘﯿﻖ ﺷﺮﮐﺖ ﮐﺮدﻧﺪ. آزﻣﻮدﻧﯽ ﻫﺎ دو آزﻣﻮن ﻓﺰآﯾﻨﺪه اﺳﺘﺎﻧﺪارد را در اواﺳﻂ ﻣﺮﺣﻠﻪ ﻟﻮﺗﺌﺎل و ﻓﻮﻟﯿﮑﻮﻻر ﺧﻮد ﺗﺎ ﺳﺮﺣﺪ واﻣﺎﻧﺪﮔﯽ اﻧﺠﺎم دادﻧﺪ. درﺧﻼل آزﻣﻮن ﮔﺎزﻫﺎي ﺗﻨﻔﺴﯽ ﺑﻄﻮر ﻧﻔﺲ ﺑﻪ ﻧﻔﺲ ﺟﻤﻊ آوري ﺷﺪ. آﺳﺘﺎﻧﻪ ﺑﯽ ﻫﻮازي ( اﻓﺰاﯾﺶ ﻧﺎﮔﻬﺎﻧﯽ در ﻣﻌﺎدﻟﻪ ﺗﻬﻮﯾﻪ اي اﮐﺴﯿﮋن(VE/VO2))، ﻧﻘﺎط Fatmax و cross over (ﺑﺎ اﺳﺘﻔﺎده از ﻣﻘﺎدﯾﺮ RER)ﺗﻌﯿﯿﻦ و ﺿﺮﺑﺎن ﻗﻠﺐ و اﮐﺴﯿﮋن ﻣﺼﺮﻓﯽ ﻣﻌﺎدل ﺑﺎ آﻧﻬﺎ اﺳﺘﺨﺮاج و اﯾﻦ ﻣﺘﻐﯿﺮ ﻫﺎ ﺑﯿﻦ ﻣﺮاﺣﻞ ﻣﺨﺘﻠﻒ ﻗﺎﻋﺪﮔﯽ ﺑﻮﺳﯿﻠﻪ آزﻣﻮن t زوﺟﯽ ﺑﺎﻫﻢ ﻣﻘﺎﯾﺴﻪ ﺷﺪﻧﺪ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﺳﻄﻮح اﺳﺘﺮادﯾﻮل و ﭘﺮوژﺳﺘﺮون در ﻣﺮﺣﻠﻪ ﻟﻮﺗﺌﺎل ﺑﻄﻮر ﻣﻌﻨﯽ دار از ﻣﺮﺣﻠﻪ ﻓﻮﻟﯿﮑﻮﻻر ﺑﺎﻻﺗﺮ ﺑﻮد (0/05

Background and Purpose: Hormonal variations throughout the menstrual cycle is usually associated with change in exercise performance. The purpose of the current study was to investigate the effect of menstrual cycle phases on aerobic performance, substrate selection, and physiological variables corresponding to anaerobic threshold (AT) in active women of Kerman city. Methodology: Twelve active females owning regular menstrual cycle participated in the study. The subjects performed two standard incremental tests at their own middle of follicular or luteal phase until exhaustion. Breath-by-breath respiratory gases were measured throughout the test. AT (abrupt increase in oxygen equivalent (VE/VO2)), cross over point (COP) and Fatmax (using respiratory exchange ratio (RER)) were determined, then heart rate and oxygen consumption corresponding to them were extracted and compared between menstrual cycle phases using paired sample T-Test. Results: Estradiol and progesterone levels during luteal phase was significantly higher than those from follicular phases (P < 0.05). The values of oxygen (ml.kg.min) corresponding to AT (follicular: 30.8±3.3, luteal: 34.6±2.1), Fatmax (follicular: 16.2±1.6, luteal: 19.1±1.7), and COP ((follicular: 18±3.3, luteal: 21.8±4.5) were significantly different between the phases (All P < 0.05). COP was occurred during follicular and luteal at 200±72 and 230±67, respectively, and the difference between phases was significant (P < 0.05). Conclusion: In sum, the results of the present study showed that different values of sexual hormones probably result in improvement in AT and seemingly do this due to change in substrate selection toward fat oxidation at intensities below the AT.