Akemi Nakagaki1,2, Takayuki Inami3, Tetsuji Minoura4, Reizo Baba5, Satoshi Iwase2, Motohiko Sato2. 1. School of Nursing/Graduate School of Nursing, Nagoya City University, Nagoya, Japan. 2. Department of Physiology, Aichi Medical University, Nagakute, Japan. 3. Faculty of Sport Sciences, Waseda University, Tokorozawa, Japan. 4. School of Nursing & Health, Aichi Prefectural University, Nagoya, Japan. 5. Department of Cardiology, Aichi Children's Health and Medical Centre, Obu, Japan.
Abstract
AIM: To test the hypothesis that autonomic neural activity in pregnant women during exercise varies according to gestational age. METHODS: This cross-sectional study involved 20 healthy women in their second (n = 13) or third (n = 7) trimester of pregnancy. Incremental cardiopulmonary exercise testing was performed with an electromagnetic cycle ergometer. Heart rate variability was analyzed by frequency analysis software. RESULTS: The low-frequency to high-frequency (LF/HF) ratio, an indicator of the sympathetic nervous system, was significantly higher in third trimester than in second trimester subjects (P < 0.05) at 1, 2, and 3 min of incremental exercise testing. In contrast, the HF/total power ratio, an indicator of rapidly acting parasympathetic activity, was significantly higher in second trimester than in third trimester subjects (P < 0.05) at 2 and 3 min. In addition, a negative correlation was found between gestational age and the 'accumulation half-time' of the LH/HF ratio, the time point at which the sum of the LF/HF ratio reached 50% of that accumulated in the total 6 min of exercise testing (r = -0.49, P = 0.028). CONCLUSIONS: The autonomic response to exercise in pregnant women differs between the second and third trimesters. These differences should be considered when prescribing exercise to pregnant women.
AIM: To test the hypothesis that autonomic neural activity in pregnant women during exercise varies according to gestational age. METHODS: This cross-sectional study involved 20 healthy women in their second (n = 13) or third (n = 7) trimester of pregnancy. Incremental cardiopulmonary exercise testing was performed with an electromagnetic cycle ergometer. Heart rate variability was analyzed by frequency analysis software. RESULTS: The low-frequency to high-frequency (LF/HF) ratio, an indicator of the sympathetic nervous system, was significantly higher in third trimester than in second trimester subjects (P < 0.05) at 1, 2, and 3 min of incremental exercise testing. In contrast, the HF/total power ratio, an indicator of rapidly acting parasympathetic activity, was significantly higher in second trimester than in third trimester subjects (P < 0.05) at 2 and 3 min. In addition, a negative correlation was found between gestational age and the 'accumulation half-time' of the LH/HF ratio, the time point at which the sum of the LF/HF ratio reached 50% of that accumulated in the total 6 min of exercise testing (r = -0.49, P = 0.028). CONCLUSIONS: The autonomic response to exercise in pregnant women differs between the second and third trimesters. These differences should be considered when prescribing exercise to pregnant women.
Authors: Olga Roldan Reoyo; Jose Castro-Piñero; Lidia Romero-Gallardo; Linda E May; Olga Ocón-Hernández; Michelle F Mottola; Virginia A Aparicio; Alberto Soriano-Maldonado Journal: BMJ Open Sport Exerc Med Date: 2022-09-23