soccertese, thanks for bringing this up.
Both my parents died, aged 57, of heart disease. So, I was keen to follow the links. It turns out to be a good example of the difficulty of reporting science.
It's no fault of yours, but given the article you refer to, I think the final word of your title has been truncated from "factors" to "fact", which is a stronger statement than that intended.
The article says "Daily activities, such as fast walking and jogging, can curb the development of risk factors for heart disease and stroke by as much as 50 percent", which is stronger than how it reports it later: "fast walking speed halved the risk, while jogging cut the risk by 40 per cent."
It is also worth pointing out that the article mentions "heart disease" and "stroke", while the underlying paper uses "heart disease" only to report other work and "stroke" not at all. It uses the term metabolic syndrome (MS). [Note for most people the unusual use of the term "MS"]. To be fair MS is linked to them, but it is not them.
For many of their results Laursen et al. use odds ratios. This is correct, but as wikipedia says: "Odds ratios have often been confused with relative risk in medical literature. For non-statisticians, the odds ratio is a difficult concept to comprehend, and it gives a more impressive figure for the effect. ... However, most authors consider that the relative risk is readily understood". 
What I want to know is the probability of something bad happening if I exercise more compared with if I carry on as now. This applies as much to Parkinson's Disease as heart disease.
 "Fast walking and jogging halve development of heart disease and stroke risk factors"
 BMJ Open2012;2:e001711 doi:10.1136/bmjopen-2012-001711
"Intensity versus duration of physical activity: implications for the metabolic syndrome. A prospective cohort study"
Adam Hoegsbro Laursen, Ole P Kristiansen, Jacob Louis Marott, Peter Schnohr, Eva Prescott