The 10 Second Supramaximal Exercise Burst Experiment
We have done a 20-second burst but for one HIIT session we did a 10-second burst experiment. I wondered what could happen in a 10-second burst. What could go wrong?
Brittany is our tester. She is 30 years old and wanted to get in better shape (with relatively little effort!). Upon hearing about the Myoride Exercise Machine and the experiments I was doing she became a willing subject.
Prior to this 10-second HIIT session, Brittany did the 20-second HIIT burst experiment for one week prior. In just 4 minutes of active exercise she lost 5 pounds, lost 4% body fat, and reduced her BMI by 3 points. In 4 minutes of total exercise!
This the first 10-second burst and was on a Friday. And this is a report of one session of the 10-second HIIT burst experiment, minus interval #2. For whatever reason, maybe my finger was over the lens or we messed up somewhere, this interval is not recorded.
Please understand we do not have a fully equipped laboratory. I have a $500 Tuffsat that works depending upon the warmness of the tester’s fingers; if they are cold we do not get accurate readings. Since this is the case because either the room is cold because I'm cheap on heating it or because blood is shunted away from the fingers during the high intensity, I use a simple pulse oximeter which seems fairly accurate to measure heart rate. In addition, I purchased a Fitbit wristband which we’re using also. I realize that electrodes or other sensors are more accurate but this is where we are at this point. It will be great to measure VO2, and EKG and other such, but for another day. This is basic research not meant to compile for professional publication.
In all the experiments we take three heart rate measurements:
Maximum heart rate.
60-seconds after stopping.
120-seconds after stopping.
From these measurements, we can follow Heart Rate Recovery (HRR) over the intervals during the session. I’m finding that there are unexpected differences in HHR between the 60-second and the 120-second marks. In other words, sometimes the 60 second HR will recover in one interval compared to the previous interval but the 120 second HR will not recover. Then, the very next interval they may switch; the 60 second HR will not recover and the 120 second HR will recover. This may be due to equipment error or slow calibration of HR or could actually be a function of recovery. I need someone to help me understand this. In any case, on with the experiment.
This is a view of the test form I complete for each tester. We get preliminary data so we can compare post 3-week trials. For this we get BMI, %fat, number of pushups, weight. I would have liked to get resting heart rate and blood pressure and I'm not sure why we didn't other than to say, it's just me and a lot of numbers.
On the form, notice on the left, next to date is the resistance levels. We can adjust the resistance on each limb, and I’m changing this as the session intervals continue, so we can keep velocity relatively the same. I think this is one of the most remarkable attributes of the machine; change the resistance levels on each of the four independently moving limbs.
For velocity, which is a function of exercise, I used the cadence of the arm/leg swing and mark it on the form. Brittany usually does 16 cycles of arm/leg swing in 20 seconds. In 10 seconds, she started at 8.5 cycles but watch Interval #3, she slows to 8. So normally I would reduce the resistance in the legs because the arm swing needs far less resistance and usually tires the quickest so we can keep velocity the same as possible. So watch her arm swing and you'll see what I mean. I usually do a good job explaining this in most of the intervals.
Now, on to the experiment descriptions.
#1 Interval — the first exercise burst. She works for 10 seconds. Her supine resting heart rate 73 bpm and we get to 136 bpm; in 10 seconds! Also, notice she does 8.5 cycles of arm/leg swing. This is her velocity. We want to keep this fairly consistent.
#2 Interval — missing!
#3 Interval — Brittany's heart rate goes to 141 bpm in 10 seconds. I state that we have the heart rate increase as high in the 10-second burst as we did in the 20-second burst. I’m looking at the test form that I’m marking everything on. Her arm/leg swing is 8 cycles.
Her 60 second HR was 85 bpm.
#4 Interval — Brittany's heart rate climbs to 153 in 10 seconds. Her 60 second heart rate is 96 bpm which is higher than the previous 60 second HR readings.
Notice her arm swing was 8 cycles.
#5 Interval — I say that her arm swing was 8 during #4 interval but it was really 8.5 and it isn't cycles per minute, it's just cycles per time measured (she didn't do this for one minute). Her arm/leg swing in #5 interval was 8.5, so we see that her velocity is staying the same.
In this #5 interval, Brittany's heart rate is 158 bpm starting at a "interval resting HR of 82 bpm. Her 60 second HR was 103 bpm.
#6 Interval — Her maximum heart rate in this 10 second burst is 150 bpm. Her 60-second HR is 98, again she is not recovering her heart rate as she did the first few intervals.
She is 8.5 arm/leg swing so her velocity remains constant although there is noticeable facial expressions of angst on her face. And her face gets red. In my book she is done exercising! Any more exercising will do her no good. Although she could have quit one interval earlier, this time she is done. She should not exercise for at least two days. It may take her over 60 minutes or more for her heart rate to fully recover to resting HR.
She's noticed that her arms are more toned over the past two weeks of the experiment. This is exactly why I have all testers, before they begin this experiment, drop down and do as many pushups as they can. Then we will have them repeat as many pushups as they can after the 3 week experiment.
And we continue with our experiment - HIIT bursts. I would consider these supramaximal bursts and that’s maybe how they should be described. Although we are engaging major muscle groups I realize that Type I fibers are being activated while I would like most to be Type II B, fast twitch. We’ll see how we can improve on this. Regardless, this is a very good workout for anyone in just seconds.