The purpose of this investigation was to determine the effects of antioxidant supplementation on DNA damage following exercise. Fourteen subjects were randomly assigned to one of two groups and required to ingest either antioxidants (400 mg α-lipoic acid, 200 mg co-enzyme Q10, 12 mg manganese, 600 mg vitamin C, 800 mg N-acetyl cysteine, 400 μg selenium, and 400 IU α-tocopherol per day) or placebos for 7 d. Exercise increased DNA damage, PS, FRAP, and LDH (P < 0.05), but not selectively between groups. LDH and PS concentration decreased 1 h post-exercise (P < 0.05), while LH concentration decreased 1 h post-exercise in the antioxidant group only (P < 0.05). The antioxidant group had a higher concentration of LH (P < 0.05), perhaps due to a selective difference between groups post-exercise (P < 0.05). The main findings of this investigation demonstrate that exhaustive aerobic exercise induces DNA damage, while anti-oxidant supplementation does not protect against damage.
G.W. Davison, C.M. Hughes, and R.A. Bell
Julia C. Orri, Elizabeth M. Hughes, Deepa G. Mistry, and Antone Scala
The authors compared the linear and nonlinear heart rate variability dynamics from rest through maximal exercise in postmenopausal women who trained at either moderate or high intensities. The outcome variables included the RR triangular index, TINN, SD1, SD2, SD1/SD2, DFA α1, DFA α2, and α1/α2. Maximal exercise reduced SD1, SD2, DFA α1, DFA α2, α1/α2, RRTri, and TINN in both groups and increased SD1/SD2 (p < .05). Two minutes of active recovery produced significant increases in SD1, SD2, DFA α1, and TINN, compared with exercise in both groups (p < .0001). There was also a significant main effect between groups for RRTri during exercise recovery, with the moderate group achieving higher levels (p < .04). The authors have shown that both moderate and vigorous exercise training can lead to a healthy response to maximal exercise and recovery, with the moderate group having a slightly improved recovery in the triangular index.
Louise C. Mâsse, Teresia M. O’Connor, Andrew W. Tu, Allison W. Watts, Mark R. Beauchamp, Sheryl O. Hughes, and Tom Baranowski
The purpose of this study was to compare the physical activity parenting practices (PAPPs) parents report using with the PAPPs incorporated in the published literature.
PAPPs in the literature were identified by reviewing the content of 74 published PAPP measures obtained from current systematic reviews supplemented with a literature search. The types of PAPPs used by parents were identified by surveying a stratified sample of 134 Canadian and US parents of 5- to 12 year-old children. Items from the literature and parent responses were coded using the same coding scheme. Differences between the PAPPs emphasized by the parents and the literature were examined.
Parents significantly emphasized different issues than what is measured in the literature (P < .001). Parents emphasized more control (13.6% vs. 6.9%), modeling and teaching (13.2% vs. 9.2%), and structural strategies (32.2% vs. 28.6%) and less autonomy support (11.8% vs. 14.0%), logistical support (9.9% vs. 12.8%), and responsiveness strategies (19.3% vs. 28.5%).
Physical activity practices most often employed by parents are not the ones emphasized in current measures. The extent to which putting more emphasis on the areas identified by parents will increase the predictive validity of the measures warrants further examination.