There will a period of silence held before the start of the London Marathon and runners are also being encouraged to wear black ribbons after the Boston marathon blasts.
Virgin London Marathon, the organisers, have pledged to donate £2 for every finisher in the race to The One Fund Boston set up to raise money for victims of the explosions.
Roughly 35,500 people are expected to cross the finish line on The Mall, meaning at least £70,000 is likely to be raised.
Tatyana McFadden, who won the women's wheelchair race in the Boston Marathon on Monday, has confirmed she will still take part in the London Marathon and is 'running for Boston':
More top news
Bob Geldof revealed that he "half expected" the death of his daughter Peaches due to the "way she was carrying on".
A mother has told how donating her son's organs after he died in a freak accident helped save six other lives.
A woman died during scenes of panic at a Kenyan university after police carried out a terror drill without the students being told first.