HDL Cholesterol: Normal Values and What a Low HDL Means

Your HDL result is the amount of cholesterol travelling inside the smallest, densest lipoproteins in your blood. Those particles collect cholesterol from your cells and from the artery wall and hand it in at the liver. What the test does not measure is how many HDL particles you have and how well they do that clean-up work. So you are reading the cargo, not the capacity.

For anyone tracking a panel that difference is decisive. An HDL of 1.6 mmol/l in an endurance athlete and an HDL of 1.6 mmol/l in someone who drinks daily represent completely different situations, and the blood result cannot tell them apart. The number takes its meaning from the context around it, not from itself.

The unit is mmol/l and the reference has a lower limit only: 1.0 mmol/l for men, 1.2 mmol/l for women. That sex difference surprises many people. Oestrogen lifts HDL, so women sit higher naturally and their lower limit sits correspondingly higher. A value of 1.1 mmol/l is therefore perfectly normal in a man and too low in his training partner. If you compare numbers within a training group, keep that difference in mind.

One link you need to know, or you will misread your panel: HDL moves inversely with triglycerides. A transfer protein swaps cholesterol out of your HDL particles in exchange for triglycerides from the fat-rich particles, after which the loaded HDL particle is broken down faster. A period of high carbohydrate intake, weight gain in a bulking phase or heavy drinking in an off-season pushes your triglycerides up and drags your HDL down with it, without anything being wrong with the HDL particles themselves.

Fasting is not needed for HDL. The value barely shifts after a meal, unlike your triglycerides.

In sporting circles HDL gets treated as a scoreboard: the higher it is, the better your aerobic base, the healthier your heart. That reasoning fails at every point, and it pays to be precise about what HDL actually does in a sports context.

Training raises HDL, but far less than you hope. Regular aerobic exercise demonstrably raises HDL, but the order of magnitude in meta-analyses is roughly 0.05 to 0.1 mmol/l, built up over months, and duration per session weighs more heavily than intensity. A block of interval training will not lift your HDL from 1.0 to 1.5 in four weeks. Anyone using HDL as a training goal has picked a variable that responds slowly, slightly and noisily. Your power output, your heart rate variability and your watts measure your form; your HDL does not.

Androgenic agents are the elephant in the room. No lifestyle factor moves HDL as hard as the use of anabolic androgenic steroids, and above all the oral, 17-alpha-alkylated variants. In controlled research, HDL under stanozolol fell from 59 to 29 mg/dl, roughly a halving, while LDL rose over the same period. The mechanism runs through the liver, which under these agents breaks HDL particles down faster. That is exactly the pattern that shows up in strength athletes' blood work: everything apparently normal, except an HDL that has collapsed and an LDL that has climbed. Injectable testosterone does this far less markedly than the oral, alkylated agents, but it does not leave the lipids entirely untouched either. If you see this pattern in your results, discuss it openly with a doctor.

And higher is not better. The relationship between HDL and all-cause mortality is U-shaped. In two large Danish population studies, together more than 116,000 participants, the lowest mortality sat around 1.9 mmol/l in men and 2.4 mmol/l in women; above roughly 3.0 mmol/l in men, mortality climbed again. On top of that, drugs that raised HDL by tens of percent did not reduce heart attacks, and people carrying a genetic variant for a higher HDL do not have a lower risk because of it. HDL is a gauge of your metabolic state, not a dial you can turn.

What does that mean for your panel? Use HDL as context. A falling HDL alongside rising triglycerides in a bulking phase tells you that your metabolic state is moving with your calorie surplus. For your actual risk you look at LDL, non-HDL cholesterol and ApoB, the number of risk-carrying particles. Your HDL says nothing about those.

HDL belongs in a full lipid profile, together with total cholesterol, LDL and triglycerides. Drawn on its own the value is barely interpretable.

Fasting is not required: HDL hardly moves after a meal. Your triglycerides do, and they can distort the calculated LDL, so for the full picture a fasting draw is still the cleanest.

For athletes there are two timing rules that do matter. Do not draw in the days immediately after a race, a marathon or an extremely hard session: acute exertion shifts the lipids temporarily, and you would be measuring the aftermath instead of your baseline. And do not draw during or shortly after an infection or an operation; the whole lipid profile dips for weeks then and gives an over-optimistic picture.

Testing is particularly useful as a fixed value in a periodic panel, at the start and the end of a longer training build, at a switch between a bulking and a cutting phase, and when you use or have used androgenic agents. In that last case HDL is the most sensitive value in your entire lipid panel and belongs to be followed alongside LDL and ApoB.

The table below summarises what your HDL does in different situations.

Have an abnormal result repeated before basing a training or nutrition decision on it, preferably at the same laboratory.