People often email me asking how many days per week should they workout. For the average person wanting to lose weight and focus on fat loss, the answer is simple. They will get fantastic results by training hard only three days per week. Now for the average person, that should be manageable.
And yes, all three of those workouts should be done in less than an hour. Research shows that 20-30 minutes of interval training is more effective than 40 minutes of slow cardio for weight loss. Combine the intervals with 20-30 minutes of strength training. Do that 3 days per week, and pow, you'll lose fat fast. (With good nutrition too, of course!)
On off days, I encourage people to be as active as possible, but without making extra effort to go to the gym. Walking to do your errands for an hour is great, if you have the time. Just do some form of health-promoting exercise (which can mean a half hour walk, yoga, or aerobic training if you desire). The duration and intensity of these off-day workouts depends on your fitness level, your recovery capacity, and your nutrition plan.
For many people, New Year's resolutions mean a return to high-volume cardio programs. But I urge restraint, caution, and conservatism. Trying to re-do your old running programs after some time off is a recipe for disaster.
If you plan on resuming a former running program, please start conservatively, especially if you are running on hard surfaces. Start easy. Build up in volume. Monitor your energy levels, strength levels, and mood. Be conservative, train consistent, and superior results will be yours.
And what about for beginners? How often should they workout?
Well, if you are the utmost of beginners, and haven't done any formal exercise in a long, long time, then simply do 3-6 bouts of 5 minutes of walking each day. Every day. Progress with your walking by increasing the time you walk and decreasing the number of "bouts" per day. For example, in week 3 of your exercise program, do 3 bouts of 10 minutes per day. And by week 6, you should be able to walk for 30 minutes straight. That is a place to get started.
At the same time, combine your walking program with a professionally designed bodyweight 3-day strength program that you can do at home (heck, most beginner exercises are even done lying on the floor!). After 6 weeks, you can increase the intensity of your workout, as outlined by your personal trainer. Eventually, you can progress into a more intense 3-day per week program.