Is 1/2 hr of daily exercise enough

That's the minimum daily recommendation for adults, so I'd say yes. However, just make sure that you make the most out of that half hour.

How does one get the most of a mere 30 minutes? ( I woke up today with the same question!!) I have allotted 30 minutes out of my lunch to go to the gym, but what to do with it has me stumped.

As long as it's more than you were doing before, it will help. Any exercise is better than sitting on the couch.

As others have said, yes, it will make a difference. ANY exercise makes a difference. NEVER, EVER make "but it won't make ENOUGH of a difference" stop you from doing what you can do to add exercise.

I only have an hour but I have the benefit of a decent workout room here at work. I spend 45 minutes of it on the elliptical most days going full-tilt-boogie at high resistance. I get my heart rate up to about 150-160 and keep it there for as much of the workout as I can. The other 15 minutes, I take a shower and hustle back to my desk. Obviously you want to check with a doctor before starting an intense cardio program, especially a self-directed one.

Calories burned are proportional to what you get your heart rate up to. So try to get your heart rate up as high as you (reasonably) can. If you've only got a half hour and you can't afford to get sweaty, do what you can within the limits you have. But it's important (if you have no health issues that prevent it) to get at least a couple of good, long, sweaty cardio workouts in. They'll build your endurance rapidly and they burn off calories like you would not believe (I can toast off 600-700 calories in 45 minutes of hard work on the elliptical)

I run for 15-20 minutes and that's about all I do. I just get bored running for much longer. I have no problem and see results with doing less than 30 mins

ive lost all my weight from doing half hour workouts....every now and then i get more time and maybe get hour in!

I'm all for exercise, but the answer to your question depends on your goals. Fat loss can be accomplished without any exercise as long as you eat below your total daily energy expenditure. If you're planning on running a marathon next month, 1/2 hr per day probably won't cut it. If you want to build muscle, you'll need to eat over your TDEE and lift heavy weights.

Most of my work outs are 30 minutes of eliptical each day during my lunch hour. However, the info I have read states you really need to do some sort of weight training at least twice a week, and the information further reccomends 48 hours rest between lifting (on the same body part). So, if you could do something like weights on Mon & Thurs and cardio on the other days that would be good. I try to just add two days a week where I do some sort of lifting at home so that I get a minimum of 7 workouts in at a minimum of 30 minutes each during the week. That is all my schedule allows for with the girls and my new puppy I am training.

Absolutely! And the best part about 30 minutes is that when you really don't feel like doing it, you can tell yourself, it's only 30 minutes. Really not that long!

And what others have said - make 30 minutes count! I do 7 exercises for one minute each, rest a minute, then repeat. That's 15 minutes done aready. Then another 7 exercises x 2. Exercises include star jumps, skip rope (without the rope), pushups, squats, lunges, sit ups, bicep curls, shoulder press, burpees (shudder), plank (groan) etc

Yes. If you do weight training and eat well, 3 hours a week (1 hour a day 3 days a week) is enough to be in great shape.

You do what you can do to the best of your limits. That's all that matters. Push yourself (gently) and when you can do more, than do more.

That said, I read up on that whole "30 minutes most days of the week" recommendation from some govt agency or another...that's not the whole story.

You'll have to google around to find it if you want to read it for yourself, but what the study they did came up with was that if you are at a healthy weight and just want to maintain that healthy weight, 30 minutes is enough. If you have weight to lose, than it's 60 minutes and if you are obese OR (this part kills me) have ever been obese, even if you have gotten to a healthy weight, the recommendation was 90 minutes...and most days was meant as 5-6 not 3-4.

Of course, I don't *think* it was intended as up to 90 minutes a day of strenuous exercise...just being active at least that much of each day.