You have probably heard the advice about 150 minutes of exercise a week. It sits in most public health guidelines, and can feel like just another number to hit.
New research suggests the payoff may run deeper than the scale or your resting heart rate.
In a randomized trial at UC San Diego, breast cancer survivors who reached that weekly target aged only about one month at the molecular level over a full year.
The women in a comparison group aged nearly 10 months on the same measure.
Also read: New study: Weight-loss drug users report nails falling off
The finding was published in the Journal of the National Cancer Institute on September 30, 2026.
What biological aging actually measures
The researchers used epigenetic clocks. These are lab tests that read chemical marks on DNA, called methylation patterns, and use them to estimate how old the body looks at the cellular level.
That estimate is a person's biological age. It can drift ahead of the age on the birth certificate, especially after illness or treatment.
At the start of the trial, survivors in both groups already looked biologically older than their years. On average, their epigenetic age ran about 8.7 years ahead of their chronological age.
Also read: Here’s how eating raspberries every day can affect your body
How the trial was set up
The team enrolled 253 breast cancer survivors who had finished active treatment and reported low activity levels and cognitive difficulties.
They were randomly assigned to a 12-month remote exercise program or a general health and wellness program.
The exercise group received fitness trackers and individual coaching. The goal was 150 minutes of moderate-to-vigorous activity per week, the same target the Centers for Disease Control and Prevention recommends for most adults.
A subset of 124 women gave blood samples at the start of the study, at six months and again at 12 months for the epigenetic analysis.
Also read: Scientists discover new tick-borne virus linked to flu-like illness
What the researchers caution
This is one randomized trial in a specific group. The authors note that larger studies are needed to confirm the biological aging benefit and to see whether the DNA-level changes are what drives the cognitive gains.
Survivors who are considering starting or increasing exercise should talk with their oncology team first, especially if fatigue, bone health or lymphedema are concerns.
Also read: Two cups of blueberries a day may ease low mood after 65
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.