Power Circuits

Article by Ed McNeely

Time is a precious commodity. Most of us don’t have nearly as much as we would like. It is difficult to balance a career or school with training and family commitments. So how is it possible to juggle everything and still have an effective workout? The answer is circuit training.

 

Circuit training has been around for many years. Traditionally circuits have consisted of either bodyweight and medicine ball exercises or low weight high rep weight training exercises designed to increase muscle tone or strength endurance. While this has been the norm, circuit training can be so much more. When designed properly circuit training can be an effective way of increasing strength and power.

 

Power circuits can increase power, strength, and muscle size but they aren’t for everyone. If you like the social aspects of training and enjoy spending time in the gym this isn’t your workout. If you are training with very heavy weights, greater than 85% of 1RM you need a long rest period between sets to allow your nervous system to recover and psyche up for the next maximal effort, a circuit wouldn’t be appropriate.

 

If you are trying to cut up power circuits are probably your best bet for maintaining muscle mass while decreasing body fat. The continuous nature of circuit training keeps metabolism high through the whole workout. Research from our lab suggests that fat use after exercise is increased more with power circuits than with a traditional program.

The concept behind circuit training stays the same whether you are training for strength or strength endurance. A series of exercises are performed one after the other with little or no break between the exercises. The difference between power circuits and endurance circuits is determined by the intensity and volume.

 

In order to increase strength you need to work with at least 60% 1RM. Usually, power circuits will be performed between 75% and 85% of 1RM. Higher intensity places a greater demand on the nervous system, requiring more rest between sets, making it difficult to perform circuit style. Endurance circuits would be done with less than 50% 1RM.

Volume is the total amount of work. It is usually calculated by adding up the total number of repetitions for each exercise. For instance 6 sets of 5 reps would be a volume of 30. For strength increases the volume of training for each exercise is normally 15-40 repetitions. This doesn’t mean 15-40 reps per set but rather the total volume is 15-40. If you did 3 x 10 on the bench press you would have done a volume of 30 if you did 6 x 5 you would also have a volume of 30. More volume in a session does not mean more strength gain. The stimulus to increase strength is like the button on an elevator. Push it and it will come, pushing the button more doesn’t make the elevator come any faster. More volume in a training session will only increase the time it takes to recover. As a general rule when you increase the volume of an exercise you will need to decrease the intensity.

 Speed

 

Movement speed is critical to power development, particularly during the concentric or positive part of the movement. While slow movements have their place in a training program, the attempt to be as explosive as possible during the concentric part of the movement is the key to power development. This does not necessarily mean that the weight, particularly a heavy weight, will be moving fast; but you should be trying to move it as fast as possible. In fact researchers have shown that the attempt to move weights explosively, even when the actual movement speed is slow (due to the heavy weight), can improve power significantly. Still, the eccentric movement should be slow and controlled so that true power is developed and not momentum.

 
Think Time not Reps

 

In order for a strength circuit to be effective you need to control fatigue. Fatigue during power training circuits will be caused by either a depletion of ATP-CP, the immediate source of energy in the muscles, or an accumulation of lactic acid. If the fatigue is caused by depleting ATP-CP that’s fine because this energy system can recovery very quickly (2-4 minutes for complete recovery) and allow you to continue to work at the right intensity and speed. 

 

The recovery time from high levels of lactic acid can be as much as two hours. High levels of lactic acid will make it difficult to work at the appropriate intensity, decreasing the effectiveness of the workout. To make sure that lactic acid is not causing fatigue the duration of each station in the circuit should be kept to 15 seconds or less. Notice that we aren’t recommending a specific number of reps because this can vary from exercise to exercise, depending on the range of motion and the weight used. A lot more reps can be done on an arm curl in 15 seconds than on a squat. The goal is to do as many reps as possible in the 15 second time frame, using good technique and a controlled eccentric. When the whole circuit is completed a 2-4 minute rest is taken before the next round to allow full recovery of your ATP-CP stores.

 
Selecting the Exercises

 

The order of exercises in the circuit will also affect fatigue levels. Upperbody and lower body exercises need to be alternated to spread the fatigue as much as possible. You should alternate push and pull as well. For instance if your circuit starts with a pulling exercise like pulldowns you would then move to a lower body exercise like leg press, your next upperbody exercise would then need to be a pushing exercise like bench press and the lower body exercise would need to be a leg curl for the hamstrings.

 
Sample Circuit

 

 

This is a circuit designed to give a total volume of about 30 reps for each body part with an intensity of about 70% 1RM. You won’t be near a failure point on any of the exercises. This is fine since failure is not necessary to increase power.

 

The number of repetitions you do in each 15 second set will depend on the exercise. Arm curls and calf raises have a much shorter range of motion than back extensions or leg press so you can do more reps in 15 seconds.

 

When you achieve the desired volume, 30 reps in this example, for an exercise the exercise is eliminated from the circuit and you take a 15 second rest when you get to that station. If you look at the calf raises you will see that after two circuits you have done the required 30 reps. For the remaining circuits you now take a 15 second rest when you get to the calf raise station. Do not continue to do calf raises because this will increase the volume too much and potentially overtrain your calves. Make sure to take the rest period. Do not move onto the next exercise and skip the rest period because you will ruin the upperbody-lowerbody pattern that you need to follow.

 
Give it a Go

 

Ideally you should try to complete this circuit in under 25 minutes. If you need to wait for equipment or take a long time between stations your time will obviously increase. Pre-planning your routine by setting up your circuit in advance will prevent the rest from getting too long.  Have a “back-up” plan or alternate exercises selected and working out at “quiet” times will give you more choices and easier transitions. Full body power circuits can be done twice a week with two days rest between sessions making it a very time efficient way to fit power training into a busy athlete’s program.