As a strength and conditioning coach, I'm asked the question "What do you think about Crossfit/Yoga/HIIT?" quite often. I actually really enjoy being asked this question. It gives me the opportunity to do exactly what I want to do with my life; help others. That mission is the reason I work in an industry that allows me to serve, and it's the reason why I want to pursue a graduate degree in physical therapy. I truly believe that giving back and adding value to society is the best thing you can possibly do with your time, and I'm really blessed that I have the opportunity to do just that 8-10 hours a day.
Now, there are millions of people who work in the fitness industry. Personal trainers, strength and conditioning coaches, Crossfit coaches... the list goes on and on. Due to this, there are, dare I say, millions of philosophies concerning the best strength training practices. Some people swear by the effectiveness of the kettlebell or the long, slow run. Some pledge their lives to yoga and achieving balance and harmony with their training. Others yet claim that heavy barbell compound movements are, and always will be, king of the iron jungle.
I'm here to tell you that every single of one the above individuals are dead wrong. Each of the above examples includes an individual who is biased and jaded by a method that they enjoyed. This enjoyment kept them coming back for more. They experienced success and used that jubilation as fuel to stoke their metabolic fire. The methods that they used are all wildly different, but the core concept is the same. They enjoyed an activity, stayed consistent by practicing over and over, and slowly but surely improved and increased the difficulty progressively.
My take-home message to you in this: Find an activity you enjoy and incorporate it into your weekly routine... 3-5x/week for best results.
With that being said... I am not without bias. I love weight lifting and truly believe that everyone would benefit from finding some time to incorporate the practice into their weekly routine. The iron game can strengthen your weaknesses, help solve those aches and pains, negate the natural effects of age, and help you on your quest for a leaner, stronger body.