Lipid-lipoproteins in children: an exercise dose-response study.
OBJECTIVE
To study the effect of exercise volume on pre- and early-pubertal children's lipid-lipoprotein profile.


METHODS
Thirty-four children (15 girls) completed 12 wk of exercise training, preceded by a 12-wk control period. Sixteen (7 girls and 9 boys) expended an additional 422 +/- 5 kJ.kg BM (LOW, 100 kcal.kg), whereas 18 (8 girls and 10 boys) expended an additional 586 +/- 7 kJ.g (MOD, 140 kcal.kg) as a result of the training program. They all exercised on three nonconsecutive days per week at 80 +/- 1% HRpeak. Exercise duration was individualized to match energy expenditure targets. Plasma TG, TC, and HDL-C were measured precontrol, pretraining, and posttraining. LDL-C, TC/HDL-C, and LDL-C/HDL-C were also calculated.


RESULTS
Group mean lipid-lipoprotein concentrations did not change as a result of training energy expenditure in either of the groups (P > 0.05). Dietary composition, habitual physical activity, and body composition were also relatively stable over the intervention period (P > 0.05). In the LOW, but not the MOD group, peak VO2 (mL.kg.min) tended to increase over the intervention period (P = 0.07). Pearson's product moment correlation analyses indicated that pretraining concentrations of TG, TC, LDL-C, TC/HDL-C, and LDL-C/HDL-C were all related to the small changes seen in the lipid-lipoprotein profile (P < 0.01).


CONCLUSIONS
Additional energy expenditure of 422 or 586 kJ.kg, as a direct result of aerobic exercise training over a 12-wk period, did not cause significant alterations in the lipid-lipoprotein profile in pre- and early-pubertal children. This may indicate that the exercise volume was insufficient, the lipoprotein profiles of the majority of children in this study were classified as "desirable," or more likely a combination of these factors.
Tolfrey
Keith
K
Department of Exercise and Sport Science, Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University, Alsager, United Kingdom. k.tolfrey@mmu.ac.uk
Jones
Andrew M
AM
Campbell
Ian G
IG
D002648:Child; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D014280:Triglycerides / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008074:Lipoproteins; D014280:Triglycerides