The graph demonstrates the percentage of North Americans who were regular gymmers from 1990 to 2010, categorised by age.
Overall, the two youngest age groups exhibited generally striking patterns while the remaining two experienced more gentle fluctuations.
To commence, the figure of those aged 24-33 started off with slight changes, ending the first half of the period at 20% in 1998. Thereafter, it rose consistently to over 25% in 2006 before an insignificant drop of merely 2% in 2010. Interestingly, this age group remained as one with the greatest proportion of frequent gym visitors among all, followed by the group of the youngest adults. For those aged 18-23, their figure experienced an almost identical trend to that of those in their middle 20s and 30s. From its starting point at precisely 15%, the percentage fluctuated gently, reaching its peak at 25% in 2006 before decreasing considerably to approximately 17% in 2010.
At the meantime, the two oldest groups underwent far more stable changing patterns. After minor fluctuations in the first eight years, the proportion of those aged 34-43 going to the gym on a regular basis increased gradually to over 10% in 2010, approximately 3% higher than its starting point while that of those aged 44-53 was recorded to have declined to its initial level of over 5%, coming last place in terms of the largest percentage.