Now, if you think about it, there are 24 hours in a day, 7 days a week, for 365 days... Which means there are 168 hours in a week... So how does 2.5 hours of movement stack up? It's 1.49% (rounded) of the time alloted.
Is 2.5 hours of "movement," especially as written in the guidelines, enough, or -- and this is crucial -- of the right type to compensate for your lifestyle? The S.A.I.D. principle (specific adaptation to implied demand) rules here. What is the S.A.I.D. principle and what does it have to do with your life? Basically the principle states that no matter what activity you do, your body will adapt to it. If you sit on a couch eating bon-bons all day you will adapt to that activity. In fact you are in "perfect" condition for that life style. If you are an office worker, doing nothing else outside the day-to-day office work, your body will adapt to the necessities of the job perfectly, having just the right mix of attributes and conditioning to get you through your day. But not much more.
While 2.5 hours of movement a week might be enough for some folks, for most it's not enough, and keeping the S.A.I.D principle in mind -- the movements chosen need to be specific to the needs of the individual -- to compensate for the demands of their lives (job, home, weekend sports, et cetera), not to mention holding the interest of the individual. For some that might mean yoga, for others resistance training, or running... Or optimally some mix of all those "types" of things...
The trick, for optimal health and wellness is finding out both what you need to compensate for your daily "life," and how to implement it, so that you'll not only do the "work," but thrive upon it.