When you're trying to lose weight or improve your fitness levels, self-control is what will make or break it for you. If you don't have willpower, you're more likely to slip back into bad habits and not see the results you want. You need to ensure that you're able to stick to your plan, make healthy choices and generally make the best decisions about diet and exercise. This may mean saying no to things you'd really like to say yes to, but overall, it's the best way to achieve what you set ...