Exercise could bring added benefits for cancer patients undergoing chemotherapy, potentially reducing the amount of drugs they require, according to research led by the University of Pennsylvania.

Researchers, whose findings have now been published in the American Journal of Physiology, found that study work performed in a mouse model of melanoma showed that combining exercise with chemotherapy shrunk tumours more so than just chemotherapy alone.

The investigation had originally set out to observe the impact of exercise on the common chemotherapy drug doxorubicin, which has been linked to negative cardiac-related side effects.

Doxorubicin is known for being effective at treating a variety of cancers, but it is also known to damage heart cells – potentially elevating the risk of cardiovascular disease in the long-term.

To explore whether an exercise regimen during chemotherapy could be beneficial, the scientists brought together four groups of mice, all of which were given an injection of melanoma cells into the scruffs of their necks.

To counter the cells, two of the groups received doxorubicin in two doses, with the other two groups receiving placebo injections.

Mice in one of the treated groups and one of the placebo groups were then placed on exercise plans, where the mice walked for 45 minutes, five days a week on mouse-sized treadmills, with the rest of the mice staying sedentary.

As predicted, doxorubicin did seem to have a negative impact on the heart, however the mice who exercised were also deemed to be unprotected from the drug’s impact.

Yet, what was really surprising for the researchers, was that the mice who exercised and received the drug experienced a notable change in their tumours. It was found that the mice receiving chemotherapy and exercise had significantly smaller tumours after two weeks than mice that only received doxorubicin.

“We looked, and the exercise didn’t do anything to the heart — it didn’t worsen it, it didn’t help it. But the tumour data – I find them actually amazing,” said Joseph Libonati, senior author of the study.

“If exercise helps in this way, you could potentially use a smaller dose of the drug and get fewer side effects.

“People don’t take a drug and then sit down all day. Something as simple as moving affects how drugs are metabolised. We’re only just beginning to understand the complexities.”

As well as research being conducted on the impact of exercise during treatment, growing amounts of data has furthered the discourse suggesting that exercise could help to prevent the development of a number of cancers.

For example, one investigation has found that obesity is the cause of around 12,000 cancers each year, with physical activity potentially holding part of the answer to preventing the disease developing in some people.

Elsewhere, according to the American Association for Cancer Research's new cancer progress report, around a quarter of all preventable cancers in the United States are thought to be impacted by obesity and inactivity.