The importance of the correct use of strength training in athletic programs is clear.
Strength and Conditioning programs have been shown to improve athletic prowess (sprinting, jumping, etc) through increased strength and power levels. Periodized strength training is often incorporated before a sport specific training phase, as Clark et al (2008) suggest that athletes must have a base level of strength before training for power. One variable of strength training that has recently received a lot of interest are rest periods in-between sets. Typically, rest periods anywhere between 1-5 minutes are recommended to allow for recovery and to maintain training intensity… But what does the research suggest!?
A comparison of 3 different rest intervals on the exercise volume completed during a workout was investigated in the squat and bench press (Willardson & Burkett 2005), exercises which are extremely common in strength training programs. This study recruited 15 male college students who performed their 8 rep max (RM) for 4 sets in the squat and bench press. Each week for 3 weeks, subjects randomly used one of 3 rest periods, until each subject had performed under each condition. The rest periods in the study were 1, 2, and 5 minutes. All subjects had a background of at least 3 years strength training experience to prevent neurological adaptations occurring during the testing procedure. Spotters also oversaw both of the exercises being performed to ensure correct technique was maintained throughout and each repetition was performed at a 3-second eccentric phase, followed by a 1-second concentric phase.
Results from the study suggest that rest periods of 5 minutes when performing exercises such as the squat and bench press allow for an increased total number of repetitions compared to rest periods of 1 and 2 minutes. No real difference, however, was found between 1-minute and 2-minute rest intervals with regards to increasing volume. To conclude this research, if you are short of time when strength training, resting for 1 minute instead of 2 minutes in-between sets will not be a detriment to your strength gains based on completion of repetitions.
Strength has been defined as the maximal force that can be generated by a muscle or muscle group at a specified velocity (Kuttgen & Kraemer, 1987., Baechle & Earle, 2008). Dissipation of fatigue is, therefore, essential when strength training, to allow for muscle recovery and in-turn sufficient force production. Rest periods of 5 minutes have been shown to allow for this (de Salles et al, 2009., Willardson & Burkett 2005). The inclusion of supersets when strength training is a choice many strength athletes like to take, especially when 5 minute rest periods are prescribed. This a great way to ensure rest periods are kept to and not shortened due to boredom. So based on current research, surely the practicality of implementing longer rest intervals would positively impact training volume and intensity when training for strength!? Future studies do need to examine longer rest intervals to determine whether 5 minutes is the optimal rest period, and to determine a point of when too much rest may start to diminish performance.
References
Baechle, T.R., Earle, R.W. (2008) Essentials of Strength Training and Conditioning. 3rd edition. Champaign IL: Human Kinetics, pp 74.
Clark, M.A., Lucett, S.C., Corn, R.J. (2008) NASM Essentials of Personal Fitness Training 3rd edition. Philadelphia PA: Lippincott Williams&Wilkins, pp 255.
De Salles, B.F., Simao,R., Miranda, F., Novnes, J. S., Lemos, A., Willardson, J.M. (2009) Rest Interval between Sets in Strength Training: Review article. Sports Medicine. 39, pp 765-777
Knuttgen, H.G., Kraemer, W.J. (1987) Terminology and Measurement in Exercise performance. Journal of Strength & Conditioning Research. 1, pp 1-10.
Willardson, J.M., Burkett, L.N. (2005) A Comparison of 3 Different Rest Intervals on the Exercise Volume Completed During a Workout. Journal of Strength and Conditioning Research. 19, pp 23-26