Identifying a lack of stamina isn't hard to do; maybe you tire easily during exercise or feel weak early in a workout. Building up your stamina includes boosting your cardiovascular performance and overall physical endurance to conquer challenges when you're active. Keep in mind that your body can adapt to activities and a key element to improving your stamina is trying new things.
Warm up for about five minutes before each workout to increase blood flow and prepare your body for exercise. Engage your whole body with jumping jacks, running in place, lunges or high knees. Work at a light to moderate pace so you can avoid working too hard and exhausting yourself prior to the workout.
Alternate traditional cardio workouts with high-intensity interval training (HIIT). HIIT puts a higher demand on your muscle fibers, heart and lungs and improves your stamina in a shorter time frame. Pick an aerobic activity, like running, and alternate between working at a slower pace and a much faster pace for a total of 15 to 25 minutes. Each interval should last 30 to 90 seconds. For example, you could walk or jog for 60 seconds and then immediately sprint as fast as you can for 30 seconds, repeating these intervals for the entire workout.
Create challenges for yourself. Increase the amount of time or distance in your workouts. If you normally work out for 30 minutes, try to reach 40 minutes. If you perform activities that you can measure in distance, like cycling, add five miles on to your ride. Race against your previous performances. For example, if it normally takes you 18 minutes to run two miles, try to beat this time.
Mix it up with new aerobic activities that will help your body avoid hitting a plateau. If you normally run, go for a bike ride, hop in the pool for some lap swimming or jump rope. If you're into rowing, opt for a kickboxing class, step aerobics or an outdoor run. The goal is to engage your heart, lungs and large muscle groups with new exercises that promote increased stamina.