Ennis has unfinished business at the Olympics. She was forced to watch the 2008 Beijing Games from her home in Sheffield due to injury and she endured further frustration when she lost her world heptathlon crown last year in Daegu.
Ennis was the first to admit she did not perform well enough when losing out to perennial rival Tatyana Chernova last year and she struggles to watch back tapes of her poor javelin throws which scuppered her hopes of winning the gold.
However, having finished second in Daegu, she now has a clear focus as she heads into a career-defining competition.
If Ennis can score well in her less favourable events — the shot put, long jump and javelin — she will have gold within her sights, as the 26-year-old excels in the three running events and is easily the most consistent heptathlete on the track.
Ennis unquestionably has the talent, consistency and discipline to follow in the footsteps of Denise Lewis, the last British woman to win Olympic heptathlon gold. She proved as much on her way to victory in the 2009 World Championships, when she led the field from the first event to the last and won by a large margin, which represented a personal best score.
Ennis was driven by her desire to prove a point after missing out on Beijing a year earlier. With her world crown now gone, that desire is now back, which is bad news for her rivals.
Her father is Jamaican and mother English
Ennis is engaged to construction site manager Andy Hill
She has a chocolate Labrador called Myla
She features on the August cover of Cosmopolitan magazine
She supports Sheffield United