Stamina and endurance are different from pure strength. Endurance allows you to exercise longer. Good stamina levels usually means better circulation, energy levels and overall health. Some people are naturally better equipped to handle endurance exercise. To increase your stamina and endurance, you need to enlarge your lung capacity, build the muscles around your heart and strengthen the muscles used in endurance activities. The key is gradual increases in your daily physical activity. Ideally, you need no less than 150 minutes a week of vigorous exercise, according to the American Heart Association.
Calculate your target exercise heart rate. According to the University of Arkansas, your maximum heart rate is 220 minus your age. For example, the maximum recommended heart rate for a 35-year-old is 185. Target between 50 percent and 80 percent of your max heart rate during exercise. Use a heart rate monitor or count your beats per minute right after exercise.
Play a sport or engage in an exercise activity that you enjoy. For example, it could be a team sport such as soccer, a head-to-head sport like tennis or a solo pursuit such as swimming. Stick to light-exertion activities if you're not accustomed to exercise. Build up to more strenuous exercises as your endurance improves.
Exercise for at least 30 minutes each day. If you're a beginner, break the 30 minutes into 10-minute chunks. Ensure each session contains sustained exercise that increases your heart and breathing rate. Build exercise into your daily routine so that it becomes a habit.
Mix your routine up. For example, alternate your three chosen activities every two days. In the days in between, try jogging, swimming or gym sessions. A broader range of exercise works more of your body's muscles. Don't feel you have to do high-intensity activities every day; a brisk walk is fine every few days.
Test your heart rate after a month of daily exercise. Measure just after or during a session. Note any improvements.
Increase the intensity and duration of your sessions if your heart rate has improved. This is a sign that your stamina and endurance are increasing. For example, try swapping a low-intensity workout for a high-intensity one. This will keep your stamina and endurance building over time.