During my casual considerations an lame efforts trying to lose a stone and a half a buddy has tried and succeeded with a simple and seemingly very effective strategy....

Press-ups.

He started three months ago as a 38 year old with a bit of a gut, a smoker, a drinker and someone who lived on a pretty unhealthy diet, medium build at just under 15 stone (5' 10").

Initially he could only do around 6 press-ups.

So he started doing them every day - literally as many reps as he could manage X as many sets as he could manage.

Before too long he was doing 200 per day in sets of 15 - 20.

Not long after he'd reaced 300 in sets of 20 - 30.

He peaked at around 550 and generally does around 400 every day (Monday to Friday).

Note: he does a variety - wide handed, close handed, slow, quick

After 3 months the results:

1. he's lost 12 lbs - presuming he's gained a few pounds in muscle that's a stone of fat gone.

2. He's dropped from a 38" waist to a 33"

3. His belly is flat and he's developed his shoulders, arms and chest quite surprisingly

4. His wife is very impressed (etc.  )

Apart from the press-ups, he does a few sets of sit-ups and has generally cut down a bit on alcohol, reduced the carbs (only a bit), increased fruit and veg and tends to eat wholegrain instead of white rice/bread/etc.

The reason I think this has worked IMO:

1. press-ups are a compound exercise so he is working a range of muscles simultaneously including abs and back in order to keep the body straight - hence the drop in waistline

2. press-ups are completely convenient so he doesnt skip sessions

3. he's built muscle which has increased his metabolism so he's buring more calories at rest

4. he's stuck at it

I have to say the results are as good if not better than any three month program I've witnessed before.