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Long‐term endurance training in older adults preserves cardiovagal control but not heart rate responses to exercise
Author(s) -
Luchyshyn Torri A,
Norton Katelyn N,
Corkal Jamie C,
Shoemaker J Kevin
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.1091.29
Subject(s) - baroreflex , medicine , heart rate , isometric exercise , cardiology , autonomic nervous system , endurance training , young adult , heart rate variability , physical therapy , physical medicine and rehabilitation , blood pressure
Parasympathetic nervous system (PNS) activity decreases with age. Estimates of baroreflex sensitivity (BRS) suggest endurance training may preserve PNS activity in older adults. But, do these estimates reflect the physiologic heart rate responses to exercise? We hypothesized that long term endurance training (ET) in older adults (O) would result in similar levels of PNS control, when compared to young healthy controls (Y). Older ET adults (n = 14; 55 ± 4 years; 4 females) and recreationally active controls (n=12; 26 ± 4 years; 6 females) completed repeated 30‐sec bouts of isometric hand grip exercise (IHG) at 30% of maximal voluntary contraction. Baseline PNS was estimated using cardiovagal BRS (sequence method). The ability to withdraw PNS during IHG was assessed by the reduction in high frequency heart rate variability (HRVhf; wavelet‐based power spectral analysis; ln normalized) and the heart rate (HR) response. Mean BRS (Y: 28.8 ± 18.4ms/mmHg vs O: 23.3 ± 15.2ms/mmHg; P >0.05) and decreases in HRVhf from rest (Y: −0.45 ± 0.63 ms 2 vs O: −0.17 ± 0.36 ms 2 ; P >0.05) were not different between groups. However, increases in HR (Y: 7.24 ± 3.36 vs. O: 2.53 ± 1.5 bpm; P =0.0002) from rest were greater in young compared to old. These data suggest that long term ET in older adults can preserve cardiovagal control but not HR responses to a moderate intensity IHG compared to young. Supported by CIHR.