Some fitness claims are hard to believe, but here’s one with valid research protocol to back it up.  Researchers in the UK (J Strength Cond Res 26(8):2228-2233, 2012) wanted to find out if Kettlebell swing training could influence both maximum and explosive strength.  Short answer: Absolutely.

What did they do?  Twice a week using a 16kg KB (for those weighing > 70kg) they performed 12 rounds  of 30 seconds
on, 30 seconds off, performing as many swings as possible using correct technique.  They did not perform any other resistance exercise during this 6-week period.  
How did it work?  After 6 weeks of bi-weekly KB training, the trainee’s maximum strength
increased 12% and their explosive strength increased 15%. That’s pretty darn good for a 12 minute work out twice a week.  
It’s definitely consistent with what I’ve found using KBs for the past 10-12 years.  They’re very time efficient and impact your cardio, strength, and endurance.  The ballistic nature of the training also makes them ideal for anyone involved in the martial arts (or any other sport for that matter!).  So if you haven’t already, go out and pick up a KB in the 12-16kg range and learn how to do a KB Swing.  You’ll be in better shape in 6 weeks.

In a recent study {J Strength Cond Res 26(7) S15-S22, 2012}, the
most frequently cited perceived exercise barrier in 3 groups of non-athletes was “lack of time”.  Considering that time is one of the few things that everyone receives in the same allocation,
unlike genetics, financial support, ecosystem/environment, social/family structure etc., I tend to agree with the authors when they say that it’s “…a simple, straightforward and socially acceptable answer, it is likely that many nonathletes have no sound rationalization for their inactivity.”  In less scientific terms: it’s a lame-ass excuse.  
I think back to a discussion with an executive team where I floated an idea about an employee wellness initiative.  One of the team members told me that not everyone may be as motivated to participate as I was, because “exercise is easy for you.”  Really?   It was easy for me to make the time to exercise consistently while I was running the company, actively participating in at least 2 other local or regional Board of Directors, coaching Little League or Soccer 3-5 nights a week, traveling 30-60 days per year both domestic and international, volunteering as a Youth Leader,  while being available as a husband and father?   Yeah, that’s easy, you chowderhead.  More likely I did what every other person that has accomplished anything (exercise, school, work, family) or met a goal has done – I decided that it was important and then I did something about it.  I invested my time and energy into it.   And that’s something that anyone and everyone can do, starting from where they are.   
So don’t give me this “lack of time” BS.  Get off the couch, turn off American Idol, and take a walk, do some pushups, ride your bike, punch something, kick something, play some jiu-jitsu.  MOVE!  You can do it IF you decide that you want to and it’s important to
you.  But it’s not because you don’t have time.

(An interesting sub-note in their study - the authors mention that the data clearly showed “that the largest difference between athletes and nonathletes emerged enquiring the attitude and activity of the parents.”  Another study shows “subjects who perceived low social support from their families and personal environment were more than twice as likely to be physically inactive compared with those reporting a high degree of support.”  So if you have kids, make sure you’re setting a good example – encouraging them to be active while being active yourself!)