Not the slightest chance of overdose. There are more cost-effective ways to increase
long-chain omega-3 fatty acid intake, and vitamin E, though.

It looks like exercise and omega-3 supps do increase HDL. To increase the HDL:LDL
ratio, you should also avoid trans fats like the plague.

Lar

Metabolism. 2004 Jun;53(6):749-54.

Effects of omega-3 fatty acid supplementation and exercise on low-density
lipoprotein and high-density lipoprotein subfractions.

Thomas TR, Smith BK, Donahue OM, Altena TS, James-Kracke M, Sun GY.

Departments of Nutritional Sciences, Biochemistry, and Pharmacology, University of
Missouri, Columbia, MO, USA.

The purpose of this study was to examine the effect of combining exercise with
omega-3 fatty acids (n-3fa) supplementation on lipoprotein subfractions and
associated enzymes. Subjects were 10 recreationally active males, aged 25 +/- 1.5
years (mean +/- SE), who supplemented n-3fa (60% eicosapentaenoic acid [EPA] and 40%
docosahexaenoic [DHA]) at 4 g/d for 4 weeks. Before and after supplementation,
subjects completed a 60-minute session of treadmill exercise at 60% Vo(2)max.
Following a 24-hour diet and activity control period, blood was collected
immediately before and after the exercise session to assess lipid variables:
high-density lipoprotein cholesterol (HDL-C) and subfractions, low-density
lipoprotein cholesterol (LDL-C) and subfractions and particle size,
lecithin:cholesterol acyltransferase (LCAT) activity, and cholesterol ester transfer
protein (CETP) activity. Supplementation with n-3fa alone increased total HDL-C and
HDL(2)-C, while exercise alone increased total HDL-C, HDL(3)-C, and total LDL-C. LDL
subfractions, particle size, and LCAT and CETP activities were not affected by
supplementation. Combination treatment resulted in an additive effect for HDL(3)-C
only and also increased LDL(1)-C versus baseline. LCAT and CETP activities were not
affected by treatments. These results suggest that n-3fa supplementation or an
exercise session each affect total HDL-C and subfractions but not LDL-C or
subfractions. In addition, the combination of n-3fa and exercise may have additional
effects on total HDL-C and LDL-C subfractions as compared to either treatment alone
in active young men.