In Part 1, I discussed a study that Chad Waterbury references on his Fat Loss Research page on his website, chadwaterbury.com.
I’ll tackle one more of his references right now.
Alcaraz PE, Sanchez-Lorente J, Blazevich AJ. Physical Performance and Cardiovascular Response to an Acute Bout of Heavy Resistance Circuit Training Versus Traditional Strength Training. J Strength Cond Res. 2008;22(3):667-671
It’s not so much the study I take issue with, but the interpretation by Waterbury.
“Training in a circuit, where you perform a series of exercises instead of each exercise separately, gained popularity in step aerobic classes where everyone is weak as a kitten. However, research shows that if you perform a circuit of heavier than normal strength exercises with short rest periods you’ll get stronger and boost your cardiovascular capacity. You can’t go wrong with a circuit of pull-ups, dips and squats, resting less than 30 seconds between each exercise. No leg warmers required.”
In the study, the circuit group performed 5 sets of bench presses with a 6RM (6 repetition maximum) with sets of leg extensions and ankle extensions between each set, also 6RM. This is a far different protocol than Waterbury’s recommended Dips, Pull-ups, and Squats.
Let’s say that bench press and dips are equal exercises (arguable) for comparison purposes. This makes Waterbury’s pull-ups and squats take the place of the leg extensions and ankle extensions of the study. This is a huge difference.
Leg extensions work primarily the quadriceps (quads) and while they’re one of the bigger muscle groups on the body, will have nowhere near the demand of squats, which work the quads, hamstrings, lower leg muscles, glutes, not to mention a host of mid and upper body muscles if weighted. Now compare the demand of ankle extensions (calf raises) with pull-ups and you’ve got the same scenario – an exercise using a small muscle group being compared to an exercise which uses multiple groups of big muscles.
Why does this make a difference? During the study, the average heart rates of the circuit and non-circuit groups were about 129 and 113 beats per minute, respectively. If exercises like squats and pull-ups are used in place of leg extensions and ankle extension, you can bet your squat-built booty the average heart rate of the circuit group would have been higher than 129 bpm. Would this have an effect on the strength of the bench press exercise? We would need more research to say so conclusively, but I would bet money on it.
Actually, no I wouldn’t. I don’t bet on anything but myself and even if I did, science surprises us way too often.
And just to make sure I’m not the only crazy one thinking this way, here’s a clip from the conclusion of the study:
Our results strongly suggest that longer term studies be conducted in order to more completely assess the impact of higher resistance circuit programs compared to more traditional circuits on both muscle strength and cardiovascular fitness.
I’ll conclude this post by reminding you that I do like Chad’s workouts, I’m just not a big fan of his use of the studies in these cases.