Many years ago a study was published looking at the addition of a final set of a very low load weight after several sets of conventional training.
In the study, the subjects initially did 5 sets of 90% RM knee extension, with 3 min rests. This was generally about 5 reps per set. Then as a last set after just 30 seconds rest, they performed to failure either the same weight (90%), 70% 1RM or 50% 1RM(the low load).
The number of reps completed on that last supplementary set (6th set below) was very variable as expected but each group was able to complete near expected numbers.
Now comes the interesting part. The best growth hormone boost compared to the standard routine (just the 5 sets, with no addition) was seen in the low load group:
So it would seem that a set to failure of a low load shortly after a conventional training routine may be beneficial to the hormonal stimuli of muscle building.
Over the years, not much more came of this line of thinking until recently.
The study looked at outcomes of leg press/leg extension with different drop set, traditional and pyramid protocols. One leg was trained conventionally and the other leg was the experimental method.
The traditional group used 3-5 sets of 6-12 RM loads with 2 min rests.
The reverse drop set (called a crescent pyramid) started at 65% 1RM and rose to 85% on the last set.
The drop set group started at 65% 1RM and had 2 "drops" of 20% each by the last set.
Total volume was equalized between legs.
Maximal strength gains were no different across methods
Cross sectional muscle area was also no different across methods:
The conclusion, quoted from the paper:
CP and DS systems do not promote greater gains in strength, muscle hypertrophy and changes in muscle architecture compared to traditional resistance training
On first glance, one could be disappointed that the drop set light load group did not fare better. But a couple of thoughts.
- The reverse drop set used above (increasing weight) is not the same as the low load protocol with rising weight discussed in this blog. A low load, reverse drop set starts out at an even lower "low load" than usual, and the maximum is just slightly higher than usual (so still using a 1 RM below 60%, and this is subject to adjustment).
- The drop set group did just as well with strength and CSA, despite never training above 65% and finalizing into the 50 % range.
- Instead of looking at this as a failure of superiority, I would look at it as a way to get equivalent gains despite lower weight lifted. Getting back to the theme of this blog, some individuals just can't lift the heavy loads, but here is some supporting data that there is a workaround.
A recent study looked at the muscular gains in a group of Australian football(soccer) athletes who trained with either conventional loads + cuff restricted low loads vs conventional loads + non-cuff restricted low loads. So both groups basically did the same training (heavy and very light) but just differed in whether they had cuff restriction or not. If our premise is correct, that low loads will provide adequate ischemic conditions, the cuffs should not matter. The results bear that out:
The study conclusion was that additional blood flow restricted exercise was not helpful in the outcome of the measured parameters(sprint, jump, 3RM, endurance). But, one could also conclude that the cuff effects were just not necessary for reasonable muscle ischemia training.
In other words Kaatsu/BFR was equal to just low loads without external compression.
Now the fun part:
Given the 2 studies above, I set out to look at muscle oxygen saturation, during a combined conventional and light protocol of my own.
The first exercise is the pulldown
It consisted of 3 sets of 7-10 RM, 3-5 min rests (with some circuit training between) followed by a 1 min rest then a set to failure of the typical low load (35-50% 1RM). Sensor on lat dorsi
heavy heavy heavy 1 min rest light
heavy heavy heavy 1 min rest light
The first set was at 165 lbs (10 reps) the 190 lbs (8RM) x 2, lastly 115 lbs for almost 1 minute.
Although desaturation is not as deep, the area under the curve is probably comparable.
The next trace is doing the Lateral Raise, (full can-thumbs up), sensor on deltoid. I did not include the first 2 sets, just the last 2 - about 13 reps of 20 lbs, then 10 lbs to failure. I included the total Hb trace as well since it shows excellent muscle compression effects on overall blood volume.
last set of 13 RM 1 min rest low load to failure
Lastly the dip, again showing just the last 2 sets. Sensor on lat dorsi, conventional load (body weight +30 lbs) x 12 reps then a set of low load, (body weight - 30 lbs).
last set of 12 RM 1 min rest low load to failure
Again, oxygen drop is not as deep but it is present and of longer duration since the low load set lasts so much longer.
- An additional set of light weight shortly after conventional training leads to excellent desaturation.
- The "relative perception of effort" while doing the low load was not severe, except toward the end of the set.
- On a personal note, although at the time I was feeling no ill effects and was not sore the next day, my overall energy, strength recovery and cycling power definitely took a hit for several days after training. This type of additional exercise load should be integrated into your program gradually and realize the danger of over-reaching.
- We can assume an additional metabolic stimuli, including growth hormone will occur with the last set given the first paper.
- In keeping with the second paper (equivalent training effects no matter how the sets are structured), I would say that we may be getting the same benefit as if we did 4 sets of conventional weights but only doing 3 sets plus a perceptually easier low load set. If saving joint/tendon/ligament health is a factor, this is even more of a benefit (less heavy load lifting). So although the theme of the study would say that doing a low load at the end is not superior, that's fine as long as it's equivalent to doing a conventional load.