Some exercise and diet lessons I've learned over time:
Switch from per-day to per-week discipline. For many years I tried to exercise a set amount each day or every other day but would find my discipline would soon wane for one reason or another, causing difficulty restarting and getting back into a groove. About six years ago I switched to per-week discipline, which I've been able to adhere to 100% since then, amazing considering all the problems I was having before.
With per-week discipline I give myself a weekly quota of exercises to do, starting Friday and ending on Thursday at midnight. If I finish up the week's quota by, say, Monday, I'll have nothing more to do through Thursday. But I frequently exercise in advance for the following week's quota if I finish early; indeed for the past several months I've usually been about two weeks ahead of schedule.
Weekly discipline takes into account that some days we are unable or simply don't feel like exercising, some days we're in a groove and can do multiple days' worth of exercising, etc. Giving seven days to make the quota makes it much easier to stay on track without the energy-wasting falling-off-and-resetting of exercise plans that frequently occur when daily discipline is tried. It has one drawback in that it's better to spread out exercise over the week instead of clumping up too much on certain days, but over time I've found my exercise days to be spread out rather evenly.
Recommended quotas? Do what works for you of course, but my weekly quota is 5 hours 15 minutes of exercise, which comes out to 45 minutes per day. For me, the quota can be met aerobically (jogging, ice skating, elliptical machines, or swing dancing credited at 3 minutes per song) or via lifting weights. For the latter, I count 36 sets of whatever exercises (normally split out as six sets of six different exercises), however long it takes me to do so, as good for 45 minutes against my quota, which comes out to 1 minute 15 seconds per set. For five specific particularly good but time-consuming exercises, I let just 30 sets of those count for meeting my quota, which incentivizes me to do the best exercises.
Use the Internet and social interaction to get more out of physical exercise. For weightlifting, there's bodybuilding.com and countless weightlifting videos on YouTube to learn proper technique for specific exercises (and for some, especially those potentially involving the lower back, it's very important to have the technique right). It is good to make one's before- or after-work friends those in the gym, as it provides another incentive to exercise (similar to those who go to the same bar after work specifically to meet the friends they've made there.) For aerobic exercise, meetup.com offers running, hiking, and walking groups for most areas. The running group whose events I frequently take part in has attendees walk/jog/run say 20 minutes out and 20 minutes back, so everybody returns at roughly the same time regardless of individual running pace.
For those new to exercise routines, two suggestions:
For heavy TV watchers/'Net surfers who have trouble motivating themselves to exercise, making the watching of TV or internet access for the day contingent on walking/jogging, etc., 30 or so minutes, is one way to help ensure getting one's exercise quota, and getting it in very early. It's frequently easier to discipline oneself to not do something enjoyable until the exercises are finished than to discipline oneself to do the exercise without there being any immediate reward afterwards.
Don't buy indoor exercise machines until you first learn to enjoy outdoor exercise (providing that is an option for you). It's dispiriting for anyone to buy a machine with the best of intentions and then see it sit unused as an ugly reminder of not getting exercise in. I would suspect the greatest amount of machine purchase failures (i.e., buy the machine but it sits unused) appear to be among those who assume that outdoor exercise is unpleasant but think it will be more palatable if they buy an indoor machine that looks neat and allows them to watch TV while exercising. Problem is, exercising indoors on a machine while trying to watch TV, for many regular exercisers, is actually lousy compared to outdoor exercise. But if you haven't done much regular outside walking/jogging first, you might incorrectly assume that the unpleasantness of indoor exercise means that outdoor exercise must therefore be much worse, when in fact the opposite is true.
Further, buying a machine in order to make exercise more palatable perpetuates a fallacy that it is best to tackle early on for those wanting to get in better shape: namely, the idea that the world will end if a person has to do something unpleasant (like outdoor exercise), and that every waking minute must be spent doing pleasant things. Indeed doing outdoor exercise specifically because it is presumed less pleasant helps to toughen one up, to see that one can do unpleasant things on a regular basis and survive the experience.
Drink water instead of sodas (even diet sodas). Despite their lack of calories, in my observation diet sodas seem to encourage more eating (compared to water) in order to neutralize their roughness on the stomach, also they form part of combo meals at fast food restaurants, encouraging purchases of unhealthy foods in the process. They also consist of a bunch of chemicals and additives the body doesn't need. And if you use filtered water pitchers such as those by Brita and Pur, a lot of landfill waste (empty bottles and cans) can be prevented.
Practice food divorce. It's easier to give up 100% on a bad food item, now and forevermore, than to try to cut down 80% on that food item, because with 100% abstinence after a while you forget what the food item tastes like, and with that, lose your temptation to eat it. As Reverend Sharpton noted: "Once you give things like starches and fried foods up, you find you won't be tempted by them any more. You forget them." He probably would not have had his success had he merely cut down on such food items, because by being constantly reminded of how yummy they are are the willpower necessary to lose weight would have been insurmountable.
Food divorce is probably best done one fattening food item (or class of items) at a time while keeping the rest of your diet the same. Go several months or however long until you've well forgotten what the food item tastes like, then choose another bad food item to say sayonara to.
My food divorce started in May 2011, when I first gave up all diet sodas in favor of water. It was tough for awhile--until I reached that happy state where I largely forgot what they tasted like. And today I love ice cold filtered water. In May 2012 I gave up pizza, as I would always overeat it. About a month later I made a huge jump and gave up all processed sugars--cookies, ice cream, pies/cakes, sugar in coffee--whatever, except for the incidental amounts in bread, milk, etc., and from fruits and vegetables. It was tough for a couple of months, but I made it: Today I can look at a brownie and have little desire to eat one because I've largely forgotten what they taste like, it's not even a willpower issue any more. Indeed, my food routine is so old-hat today I don't even think of myself as being on a diet.
Around October of last year I stopped eating out, except when I'm travelling. This is forced me to become more of a cook at home, and has saved me time, money, and excess calories, as well as resulting in me eating healthier food.
Because I've given up processed sugars, I haven't bothered restricting other types of carbs such as rice or bread, etc. My total caloric intake is probably just moderately reduced, I still eat fully except none of the aforementioned food items.
For those with willpower problems, deliberately eat some plain and unpleasant food items daily. Plain foods without the salt, sugar or other seasoning that you would normally add, for example, coffee without cream or any sweetener additives, a plain baked potato or plain toast without butter. Doing so helps to toughen one up, to learn the world won't end if not every food item consumed is fantastically delicious, a mindset necessary to defeat in trying to improve one's diet. For years I thought pure black coffee with no sweetener would be impossible for me to consume, but that's the only way I drink it now. I drink much less of it as a result, but I still consume it--who cares if it isn't the most delicious thing in the world? I don't need that, I'll survive.
Don't weigh yourself. On a day-by-day basis, scales are an inaccurate measure of health and also even of weight (because weight will also vary by the clothes being worn, the amount of water and undigested food in the body, etc.) They also encourage crash-dieting and penalize weight-lifting (as weight retained may be due to gained muscle), harmful for overall health and appearance. Basically, you either look good or you don't, and the number on the scale doesn't play much of a factor in that. There are healthier long-term ways to see progress being made--looking slimmer, people noticing weight loss, clothes feeling looser, etc. In my view, dispensing with the scale forces a person to make long-term efforts to see the progress they're craving instead of allowing that craving to be met just by seeing lower numbers on the scale. In the past year, I've weighed myself very few times (and not once so far in 2013)--during my annual physical and at the gym scale right after to confirm that I had indeed lost several pounds.