A new study has shed light on the common decrease in activity during early adulthood.
Britain and the US have been experiencing a rise in obesity, with one of the major contributing factors deemed to be our increasingly sedentary lifestyles.
Researchers at McMaster University in Canada found that life transitions provide an opportunity for people to neglect their former exercise regimes, with college being a prime example.
Psychologist Steven Bray analysed 127 students and found that the majority admitted to doing less exercise in their first year of university than during the previous year.
A third of students remained active during their first year; another third dropped their activity levels; while the final third had not participated in exercise prior to university and tended to maintain this lifestyle.
The expert explained: "Unfortunately, [exercise] is one of the first things that goes when we get busy with other things.
"A lot of times it has to do with being too busy with school-related things, but it also comes down to changing social patterns," he continued.
"They get to be friends with people who are less active than they used to be…and so there may be a culture of inactivity that starts to take place at first-year university."
Mr Bray believes that universities could do more to help students adapt and to encourage them to continue exercising throughout their course, reducing their chances of being overweight as adults.
He concluded: "Personally, I believe that if we can teach people to adapt, that's going to be more successful."