A favourite phrase of teachers at every parents evening is 'They're bright, but don't apply themselves'.
Usually this cliche doesn't earn the student many brownie points, as they're essentially just being called lazy.
But according to a 2015 study, their idleness may actually be an indication of how brilliant they actually are.
A study undertaken by the Florida Gulf Coast University found that people with higher IQs are less physically active than those at the lower end of the scale.
Brainy people are more likely to engage in thought-intensive activities while giving exercise the cold shoulder.
The research used a cognition test to put subjects into two camps - thinkers and non-thinkers.
Over the course of a week, fitness trackers showed that the 'thinkers' were less active on weekdays, and showed not much difference on the weekends.
It is thought this because intelligent people are less likely to get bored, meaning they'll spend more time engaged in intellectual activities.
And despite the benefits of reading and crosswords, they don't do much to get your blood pumping.
Active people on the other hand need to keep stimulated with external activities because they're more prone to getting bored.
The British Psychological Society quoted the study, saying: "Ultimately, an important factor that may help more thoughtful individuals combat their lower average activity levels is awareness.
"Awareness of their tendency to be less active, coupled with an awareness of the cost associated with inactivity, more thoughtful people may then choose to become more active throughout the day."
Given that only 60 people participated in the study, the researchers have warned against making too many generalisations based on the findings.
The study has rung true with a lot of people however, who were overjoyed to hear they may actually be a genius.
One bloke commented: "I must be Albert f**king Einstein", while another joked: "Lazy people are smart because they get others to do the work for them."
However, there was some pushback on other corners of the internet.
One critic wrote: "You can be lazy and intelligent yes, but the real intelligent people are the ones who fight past laziness and have discipline. Easier said then done trying to do better."
Ultimately, one's intelligence can't rest solely on how much they're heading to the gym or sitting on the couch.