Circuit training

Circuit training is a series of exercise stations completed in succession with little to no rest between exercises.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 243.},^{2International Sports Sciences Association, Strength and Conditioning, p. 230.} The circuit ends when every station is done.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 243.} ISSA describes two to three rounds with 60 to 90 seconds of rest between rounds.^{2International Sports Sciences Association, Strength and Conditioning, p. 230.} A circuit can use resistance exercises alone or alternate resistance sets with short bouts of aerobic exercise.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 455.} Consecutive stations shouldn’t load the same muscle groups.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 243.}

The format fits many exercises into a short session, and the faster pace raises intensity; ISSA reports that it also raises enjoyment and motivation for many participants.^{2International Sports Sciences Association, Strength and Conditioning, p. 230.}

What does circuit training improve?

Zatsiorsky and colleagues describe circuits as an effective, convenient way to build muscular endurance.^{1Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 243.} They question whether circuits can build strength and endurance together because the adaptations compete, and report smaller strength gains than regular strength routines.^{4Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 101.} The NSCA’s personal training text reports that most studies of circuit variations found strength gains, but no significant VO2 max improvement compared with aerobic-only training.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 455.}

In practice

• Time each station and keep the load submaximal.^{5International Personal Trainer Academy, Certified Personal Trainer Textbook, p. 265.} IPTA gives an example of 30 seconds of goblet squats at 20% of one-rep max, a quick transition, then 30 seconds of V-ups.^{5International Personal Trainer Academy, Certified Personal Trainer Textbook, p. 265.}
• Use a circuit when time is short or the client needs a full-body workout, and leave 24 to 48 hours between circuit sessions.^{2International Sports Sciences Association, Strength and Conditioning, p. 230.}
• Circuits can introduce beginners to resistance and aerobic training.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 455.} The NSCA also suggests them for maintenance, reporting no evidence that VO2 max drops during a circuit program.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 455.}