Make it fun! Start your exercise routines by doing something you enjoy. Your exercise motivation can be to do something you enjoy like dancing, gardening or walking. Although your favourite activity may not be as strenuous as an aerobic workout, it's a place to start.
Plan your exercise. Most people nowadays have a very busy lifestyle and feel they cannot fit exercise into their day. Plan a specific time for 40 minutes of exercise, four times per week and you will be surprised how you can fit exercise into your life.
Mix it up. If you get tired of doing the same thing every day, change your routine. You don't have to walk the same route each day, or only ever ride a bike. Try doing different activites and different environments to keep you interested. This will also help to exercise different muscle groups.
Exercise with friends. Having people to exercise with who share the same exercise interest will keep you motivated. Knowing there is someone counting on you to be there to exercise will help you fight off excuses.
Set goals for exercise that you can follow through with. Choose activities you know you can do well and build up to harder, more strenuous activities as your fitness improves. If you are constantly frustrated with your workout or finding it too difficult, you are more likely to give up.
Incidental exercise gets you moving without feeling like you're 'working out'. Take the stairs instead of the lift, or park a little bit further away from the door at the shops; take a walk during your lunch hour, take public transport when able and walk from the stops/stations to your destination.
Reward yourself for the effort you have put in. Give yourself a bubble bath, rent a movie, get a massage, or buy that item you have been longing for. Try putting away a few dollars every time you exercise and use that money to treat yourself at the end of the month. (Remember, don't treat yourself with food!)
Listen to music or e-books while exercising, or position an exercise bike/treadmill in front of the television and watch your favourite show. You will be surprised how quickly the time passes. If you don't have equipment at home, most gyms have equipment with built in televisions, so you can watch any program you choose.
If you feel you need more help to get and stay motivated while exercising, look into hiring a Personal Trainer to help you with your workouts. They can help you to get the most out of your workouts while having the knowledge to ensure you don't injure yourself.
Don't give up because you miss one or to workouts. If you miss a workout, just start again as soon as you're able. Missing a workout is not a good reason to give up.