You do not have to be an exercise scientist to realize that the more rest you take between sets, the more weight you’ll be able to lift when you do come back. This doesn’t mean that you should always take more rest between your sets… the right amount of rest for you will depend on your goals somewhat. When you go to the gym, do you go with a plan? The answer is yes. I am sure you have been to the gym and seen people perform an exercise then either talk to a friend for ten minutes or admire their body in the mirror. If you’re training a certain energy system, you need to have the appropriate rest period to achieve your goals.
The energy systems are:
ATP-PC System (Phosphogen System) – This system is used only for very short durations of up to 10 seconds. This is the primary system behind very short, powerful movements like a golf swing or a 100m sprint. Best for short bursts of intense lifts, like in power lifting or strength training.
Anaerobic System (Lactic Acid System) – Predominates in supplying energy for exercises lasting less than 2 min. Also known as the Gylcolytic System. An example of an activity of the intensity and duration that this system works under would be a 400m sprint. This creates muscle mass, size.
Progressive resistance training exercises are designed to improve neuromuscular performance, physical function, quality of life, and to prevent and treat chronic diseases in older adults (Filho 2013). The goal of a resistance training program depends on several acute variables, such as intensity, volume, weekly frequency, movement velocity, exercise order, and duration of the rest interval (RI) between sets and exercises. The positive effects of RI between sets, on acute muscle performance in single resistance training exercises, have been examined in young and older adults.
Filho (2013) assessed the effects of different rest intervals between sets on number of repetitions, sustainability of repetitions, and total volume during a leg press exercise. Seventeen resistance-trained older women (68.0 years, 71. 2 kg, 1.58 m) participated in the study. All participants performed three sets to voluntary exhaustion, with loads that corresponded to 15 maximum repetitions, in two experimental sessions (that ranged from 48 to 72 hours apart). In each session, one of two RI (one-minute: RI-1 and three minute: RI-3) was tested, employing a randomized and counterbalanced design. For both RI, significant reductions were observed in the number of repetitions and sustainability of repetitions, from the first to the second and third sets. Differences between the RI also were observed in the two final sets. The total volume for the RI-3 session was statistically higher (29.4%), as compared to the RI-1 session. The length of the RI between sets influenced the number of repetitions, sustainability of repetitions, and total volume. The longer RI should be used, therefore, when the goal of training is to increase the total volume.
The number of repetitions, sustainability of repetitions, and total volume of experimental sessions were significantly influenced by the RI, between sets, in resistance- trained older women. Neither RI appeared to help the women maintain sustainability of repetitions in subsequent sets. However, the sessions with RI-3 reflected a greater ability for the participants to maintain number of repetitions, time of tension, and total volume.
If you are look for a personal trainer who can help you reach your goals, then COR is the place to be. With clients of all ages and abilities, COR designs individualized programs based on science and research. COR is fully dedicated to each individual.
Reference:
1. Filho JC, Gobbi LT, Gurjão AL, Gonçalves R, Prado AK, Gobbi S. Effect of different rest intervals, between sets, on muscle performance during leg press exercise, in trained older women. J Sports Sci Med. 2013 Mar 1;12(1):138-43.

Written by Chris Barber, CPT