The effect of 13 weeks of running training followed by 9 d of detraining on postprandial lipaemia.
The present study examined the influence of training, followed by a short period of detraining, on postprandial lipaemia. Fourteen normolipidaemic, recreationally active young adults aged 18-31 years participated, in two self-selected groups: three men and five women (BMI 21.7-27.6 kg/m2) completed 13 weeks of running training, after which they refrained from exercise for 9 d; three men and three women (BMI 21.5-25.6 kg/m2) maintained their usual lifestyle. Oral fat tolerance tests were conducted at baseline and again 15 h, 60 h and 9 d after the runners' last training session. Blood samples were drawn after an overnight fast and at intervals for 6 h after consumption of a high-fat meal (1.2 g fat, 1.4 g carbohydrate, 70.6 kJ energy/kg body mass). Heparin was then administered (100 IU/kg) and a further blood sample was drawn for measurement of plasma lipoprotein lipase (EC 3.1.1.34; LPL) activity. Endurance fitness improved in runners, relative to controls (maximal O2 uptake +3.2 (SE 1.1) ml/kg per min v. -1.3 (SE 1.2) ml/kg per min; P < 0.05). In the absence of the acute effect of exercise, i.e. 60 h after the last training session, there was no effect of training on either postprandial lipaemia or on post-heparin LPL activity. However, changes during 9 d of detraining in both these variables differed significantly between groups; after 2d without exercise (60 h test), the runners' lipaemic response was 37% higher than it was the morning after their last training session (15 h test; runners v. controls P < 0.05), with a reciprocal decrease in post-heparin LPL activity (P < 0.01). These findings suggest that improved fitness does not necessarily confer an effect on postprandial lipaemia above that attributable to a single session of exercise.
Herd
S L
SL
Department of Physical Education, Sports Science and Recreation Management, Loughborough University, Leicestershire, UK.
Hardman
A E
AE
Boobis
L H
LH
Cairns
C J
CJ
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006493:Heparin / Q000008:administration & dosage; D006801:Humans; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood*; D008071:Lipoprotein Lipase / Q000097:blood; D008297:Male; D010806:Physical Education and Training; D010807:Physical Endurance / Q000502:physiology*; D010809:Physical Fitness; D019518:Postprandial Period; D012420:Running / Q000502:physiology*; D014280:Triglycerides / Q000097:blood
D004041:Dietary Fats; D007328:Insulin; D008055:Lipids; D014280:Triglycerides; D006493:Heparin; D008071:Lipoprotein Lipase