Design

Perform 8 sets (only last 6 recorded) of 4 reps at 80% of my 1rm. Perform each rep with maximal effort. Record velocity of each set.

Analysis:

Calculate the rate of velocity drop-off in each set (as determined by the slope of the 4 reps). Record the Min and Max velocity of each rep in the given set. Report the raw velocities of each rep and each set.

Data

Graph 1 is the raw data of each rep’s velocity in each set. There is an obvious drop off in velocity between reps.

GRAPH 1

 

Graph 2 is a lot more interesting than Graph 1. What we have here is the slope of velocity drop-off between reps in each set (blue line and left vertical axis). There is also Max velocity and Min velocity (orange line and right vertical axis).

GRAPH 2

Graph 2 highlights the  increase in rate of velocity drop-off, as determined by size of negative slope, from set to set. It also highlights a steady increase in first rep bar velocity and a slight downward trend in last rep velocity from set to set.

What does this mean?

Firstly, rate of velocity drop-off without context to the Min and Max is dangerous. By simply looking at the slope, one would think that my abilities to maintain power were drastically dropping off. However, this is not quite the case. By looking at Max velocity (which occurred on the first rep for all set besides one), one can quickly see that velocity was actually trending upward from set to set with a relatively stagnant (possibly slight trend downward) Min velocity from set to set. This really brings up the question of how do we actually know when enough volume is enough? If we were to base it on the strict protocol of the lifting program (8 sets of 4 at 80%1rm) I should stop after 8. However, if we are to train in regards to velocity drop-off of the first rep, it appears I would have had quite a bit more in me.

Another interesting aspect of the Graph 2 is the fact the even though the first rep velocity increased from set to set, the last rep velocity did not fluctuate much. Thus the greater negative slope value suggest that my velocity properties of the muscle were increasing set to set (more warmed up, neural patterning of the movement, so other reason I can’t think of) yet the number of reps I could theoretically perform per set were decreasing (if you take the rate of velocity drop-off you can calculate this. For example if we take the first recorded set compared to the last recorded set and assumed that my last rep at failure would occur at 0.15m/s then we can actually run the math and see the number of predicted reps I had left in the tank.

 

Set 1: Last rep velocity was 0.29m/s and the slope was -0.04

Predicted rep 5 velocity would be 0.25m/s, predicted rep 6 velocity would be 0.21m/s, predicted rep 7 velocity would be 0.17m/s and then predicted rep 8 velocity would be 0.13m/s (Predicted missed rep)

Set 6: Last rep velocity was 0.28m/s and the slope was -0.068

Predicted rep 5 velocity would be 0.212 m/s and predicted rep 6 would be 0.144m/s (Predicted missed rep)

So I would actually technically have two more predicted successful reps in set 1 compared to set 2 despite the fact that set 1 had a Max velocity of 0.41 m/s and set 2 had a Max velocity of 0.48m/s

Conclusion

In honestly, I am not quite sure I can explain what is happening here. It appears that there may be a mix of an increase in neurological readiness from set to set occurring, in conjunction with fatigue. There also could be an increase in neurological readiness, which leads to a greater total power output per rep, which in turn reduces my ability for repeat efforts by increasing the metabolic demands per rep. If anyone out here is a is a dunker or has tried dunking, there is a reason why you only get a couple of good jumps a day (at least for me) and it seems like for each good rep the time to fully recover from the rep increases. Thus, because each rep or jump attempt requires more and more energy to be mobilized in the system, the rate at which this output can be maintained is decreased.