Do certain types of strength training significantly enhance a person's level of aerobic fitness?

A type of strength training known as circuit training has been shown to increase aerobic capacity by an average of approximately five percent -- this will vary depending upon the individual's fitness level and how hard the person trains. For example, one study reported that three 20-30 minute circuit training sessions a week for a period of 20 weeks improved aerobic capacity by approximately seven to eight percent -- one-third the improvement that might otherwise be expected from a conventional aerobic conditioning program. Some evidence exists, however, that circuit training can be used to effectively maintain improvements in aerobic fitness achieved through traditional forms of aerobic training (i.e., running, cycling, stair climbing, etc.).  more