Dr Alma Adler, research fellow at the London School of Hygiene and Tropical Medicine, explained:
We're really interested in the preliminary findings around fitness activity and flu-like illness, as exercise is something that everyone can do to reduce your chance of having flu.
We need to treat this result cautiously as these are preliminary findings, however they are consistent with findings for other conditions and really show the health benefits of exercise.
Although many people have dodged the flu bullet this winter, flu can occur at any time, so taking advantage of the better weather is a great opportunity to get out and get fit to ward off flu this spring.
The Government's plans to encourage NHS trusts to ensure three quarters of their workers are vaccinated from the flu "is a very welcome initiative", a lung and heart expert has told Daybreak.
Professor Peter Openshaw, director of the Centre for Respiratory Infection, welcomed plans to encourage NHS trusts to make sure their workers are properly immunised by allowing them access to some of the £250 million funding.
NHS trusts that fail to prove at least 75% of their workers have had the jab will be blackballed from emergency funding.
According to health secretary Jeremy Hunt, the £250 million the Government has pledged to tackle the perennial flu problem will be used to protect some of the UK's youngest children against the disease.
Two and three year olds in England will be offered flu vaccinations as part of the new initiative to tackle winter health problems.
GPs will administer a single dose nasal spray to toddlers alongside the annual campaign to vaccinate Britain's elderly and vulnerable.
The nasal spray flu vaccine is also for children aged two to 18 who are 'at risk' from flu, such as children with long-term health conditions.
Scientists have found a "blueprint" for a universal flu vaccine, according to the leader of a research project into influenza, said Professor Lalvan:
Our findings suggest that by making the body produce more of this specific type of CD8 T cell, you can protect people against symptomatic illness. This provides the blueprint for developing a universal flu vaccine.
We already know how to stimulate the immune system to make CD8 T cells by vaccination.
Now that we know these T cells may protect, we can design a vaccine to prevent people getting symptoms and transmitting infection to others.
This could curb seasonal flu annually and protect people against future pandemics.
British scientists are one step closer to developing a "holy grail" universal flu vaccine that would tackle all strains of the illness.
A successful jab would stimulate the body to create more immune cells capable of attacking the virus and could be effective at preventing new strains that cross into humans from birds and pigs, according to scientists.
Results from the 2009 swine flu pandemic showed patients with more virus-killing immune cells in their blood at the start of the illness, would avoid sever illness, researchers at Imperial College London (ICL) found.
Professor Ajit Lalvani from the National Heart and Lung Institute at ICL, who led the study, said: "New strains of flu are continuously emerging, some of which are deadly, and so the holy grail is to create a universal vaccine that would be effective against all strains of flu."