A bit over a year ago I re-instituted Low Carb a la Atkins. My belly weight had crept up, and as a doc I knew that was not good. My dad had had a mysterious heart "event" in the previous couple of years. My age keeps increasing and had reached upper fifties. And the final straw was the birth of two perfectly fabulous grandsons that summer. Time to make changes.
As part of my obsessive-compulsive trait (a good thing in a physician) I did a lot of surfing and found Mark's Daily Apple. In the forums, someone mentioned "high intensity training." Perhaps you've seen the BBC documentary on high intensity interval training? I had just restarted weight training and of course hurt my shoulder doing the stupid Steinborn Lift (hurt for months.) Then I found a Forum post on "Body by Science."
Could it really be true that half an hour, once a week, could give as good a result as the usual prescription of 3x/week, complex circuits, rapid movements? It turned out to be true. In the past six months my weights have basically doubled and I continue to gain strength.It feels great.
There are a couple of other resources I like. First is an article about the evidence for various types of weight training, which basically says that working muscles to momentary failure, once per week, gives as good gains as more frequent schedules of less intense exercise. A followup article which I can't find right now says that the HIT schedule also does a good job of training aerobic capacity.
What about machines vs free weights? Either is probably fine. At my age I'm liking the machines. Strength gains are just fine and I'm not hurting myself.
So, in brief, my workout is a "slow movement to failure" workout. For each exercise, the trainer sets the weight based on the previous session. I sit on the machine and start pushing the weight, slowly, out and back, out and back, usually to a count of about ten. It is KEY to never let the muscle relax--the important measures are the weight and the total time under load.
The first push is pretty straightforward, and usually the second one is as well. Third push starts to feel difficult. Fourth is when the lactic acid really builds up and it gets really tough. At this point I'm huffing and puffing! You do it slow in part so that you don't injure yourself by doing a momentary overstress of muscle or tendon.
My current goal is to reach 2 minutes under load, then he raises the weight for the next time. Abs, leg extension, isometric leg curl, lower back machine, leg press, lat pulldown, chest press, and horizontal row. 30 minutes once a week.
My trainer is at TruFit in Denver and they have been terrific. The Body by Science Website has a list of trainers around the country. So efficient, so safe, such good results! Highly recommended.