It's really great to have boobs. But they can also be annoying when jogging. They wobble, get in the way, and sometimes even hurt. You should know that

It's not a problem that only beginners struggle with: some marathon runners also have sore breasts from time to time while jogging. Sometimes they even limit their training because of this. But that doesn't have to be the case. That's what sports bras are for. Their designs continue to improve, and researchers continue to study the effect of movement on the female breast.

We reveal what every runner should know about their boobs. With it you can jog safely without pain and confidently dare to set new goals: With this training plan you can manage your first 10-kilometer run.

Why do the breasts hurt or bother when running?

There are various reasons for discomfort in the breasts during sport. Many are related to the special characteristics of the breast tissue and the "construction" of the breast. Here are the 7 most important facts and studies about it:

1. The body hardly supports the breasts

"Depending on their size, breasts can be very heavy," says Andrea Cheville, a breast cancer researcher at the Mayo Clinic in Minnesota. "But the body supports her very little. Hardly anything keeps her steady or calm." Just skin and some ribbons. It's very different for other parts of the body.

"The fascia in the abdomen, for example, is enormously strong," says Cheville. "When you run, the organs don't wiggle back and forth because they're surrounded by a strong, fibrous covering. That's not the case with the breasts. They have next to no support, but they still have pain receptors. So when they're stretched, it does that hurts."

2. Your boobs move more than you think

University of Limerick exercise scientist Michelle Norris has studied chest movement and tested products designed to support the tissue. To do this, she and her colleagues had women run on the treadmill, first topless and then in low- and high-support bras. They recorded the movements of the breast using 3D motion capture.

They noticed that the breasts move in the shape of an 8. So they not only rock up and down, but also sideways and forwards and backwards. "Boobs are all tissue, not muscle," says Norris. "They are not rigid but can move in all 3 dimensions when we walk." And they do.

If you add up the movement in all 3 planes, Norris says breasts move about 15 centimeters with each stride. Of course, this varies depending on the cup size. About 50 percent of the movement is vertical and 25 percent each sideways, forwards and backwards.

3. Nothing works without a good sports bra

With so much movement in all dimensions, you need a good bra that holds everything nicely. Some women prefer tight bras that keep everything in place, others prefer bras that "encapsulate" the breasts, i.e. hold them in firm cups. But it doesn't matter which variant you choose. In the end, the best bra is still the one that you're comfortable in. "The most important thing is that the bra fits perfectly," says Norris.

Here are 3 sports bras for optimal support while running:

Price-performance tip: Sports bra from Nike (€32.95)
Quality tip: Air Control Delta Pad by Anita Active (74.95 €)
For big breasts: Run Bra by Shock Absorber (€54.95)
Tip: If you have a model with a clasp at the back, start with wearing it in the widest setting. If it becomes wider later through washing, you can tighten it even further.

4. The breasts move the same amount no matter the speed

Norris surprised herself when she discovered that no matter how fast you run, your breasts move the same amount. "I thought the faster I ran, the more they moved. But they don't," she says. "When you run at 10 km/h, they've reached their maximum range of motion. At 14 km/h they don't move any more.”

Therefore: Even with a slow basic endurance run, you need a bra that offers your breasts good support at all times.

5. How running can make breasts smaller

Women who are new to running often notice strange breast shrinkage. What happens there? Running itself does not reduce your bust size. It is made up of fat and tissue.

But: "If you run regularly, eat well and lose body fat as a result, you lose weight in your breasts accordingly," says Norris. But: "It's not just your breasts that get smaller, you lose weight overall."

6. Periods also increase chest pain

There are different types of chest pain, and most of them are easy to explain. Still, you shouldn't ignore them. The pain often comes from not having enough support – then the bra does not serve its purpose. It can be difficult, especially for women with voluptuous breasts, to find the right model.

Many women are particularly sensitive to their breasts, especially just before their period. This differs from woman to woman. If you're in severe pain during this time, consider doing a workout with less jerky movements. "Accept that this will pass. And take it easy while you're more sensitive," says Cheville. Here we show what the best training is for each.