Interval training involves short bouts of high intensity work followed by a longer bout of lower intensity work. In a study published in the October 1996 issue of the journal "Medicine and Science in Sports and Exercise", researchers found that subjects who performed moderate cycling exercises for 60 minutes a day for six weeks improved their aerobic endurance but experienced no change in anaerobic endurance. Another group of cyclists who performed eights sets of high intensity, 20-second intervals with 10 seconds of rest in between for six weeks not only improved their aerobic endurance more than the moderate intensity group but also improved their anaerobic capacity by 28 percent.
Lifting weights is mostly anaerobic and not only improves your strength but also your muscular stamina and your ability to perform activities of daily living such as vacuuming, shoveling snow or gardening for extended periods of time. According to the National Strength and Conditioning Association, to experience both strength and endurance gains in weightlifting, you need to lift a weight heavy enough that you experience muscular fatigue within eight to 15 repetitions. Perform weight training exercises at least two days per week, working every major muscle group with about eight different exercises per session.
Circuits involve three to 12 different stations that incorporate strength training, cardiovascular exercise or both. Circuits emulate everyday life because your body does not get a break from movement, however individual muscle groups do. They challenge your strength and both anaerobic and aerobic endurance, making it the perfect combination for improving stamina. To do a circuit, combine basic strength training exercises and do each one for 30 seconds before moving on to the next. Give yourself a 30-second break in between each exercise. As your stamina improves, reduce your rest time to 15 seconds and increase your work time to 45 seconds.
The best way to improve your aerobic endurance and therefore your ability to withstand low to moderate intensity work for a long time is with prolonged cardiovascular training. Start with 30 minutes of low to moderate intensity cardiovascular exercise such as walking, jogging, hiking, cycling or swimming. Each week try to increase the amount of time you can exercise by five minutes or increase your distance a little. Add another quarter mile on the walk or jog, or another lap in the pool.