We recently ran a cycle where we completed the workout “Fran” (21-15-9 reps Thrusters and Pullups) every Friday for 6 weeks, we kept the total volume the same but changed the set / rep combination week to week, apart from being the highlight of everyone's week, what did we or what can we learn from this little experiment?
Firstly in review - our 6 versions of Fran were
15 / 15
9 / 9
5 / 5
45 / 45
After 6 weeks of largely performing the same workout you would have no doubt decided which variations you preferred over others, but some of your reasoning (I suspect) may have been based around which option felt “easiest” and unfortunately that does not constitute a reliable scientific metric for determining exercise effectiveness. We need to look at the goal of the workout - which is to generate as much power as possible (ie make you work as hard as you can to elicit the greatest response from your body). Power being Force x Distance / Time, now we have the Force (the weight / movement) and Distance (unless you got taller or shorter over the 6 weeks) remaining constant over the 6 weeks - ignoring extra cleans / trips to the pullup bar in the higher set / lower rep variations, the only factor that is changing in our Power equation is time.
Hopefully you were a diligent swoldier of fortune and made it in every week and have a time for all 6 weeks and can easiest pin point the week which had the fastest time, simplifying everything - this combination was the most effective for you in terms of power generated (ie making it the most “effective” workout for you)
Taking a rough stab in the dark, the majority of people would have achieved the most joy with Fran 3.0 and 4.0 which had the most rounds and the smallest amount of reps (9 and 5 respectively. Generally speaking someone of reasonable fitness (but not high level / elite ) finds it easiest to pace and keep sets unbroken in these combinations, does this mean since this is where you are generating the most power here that you should always modify your workouts to a similar rep scheme to elicit the most out of each workout? Not necessarily, for those not at the super pointy end of the CrossFit field there is a few more factors which can cloud the data -
1. through practice you got better at the combination of movements - if you havent done Fran a 1000 times in the past, merely by performing a combination of thrusters week in and week out, you got more used to it and were able to move and perform more efficiently .
2. you dont know what you are capable of (or the brain often gets in the way of a good workout) - doing 21 or 45 thrusters in a row can be a mentally (and physically daunting task) so you will tell yourself to stop before you actually need to, broken up in to small chunks of 5 or 9 tho it seems a lot more palatable and its easier to tell yourself to keep going
3. you have a particular weakness / strength in one of the movements - having a particular weakness / strength in one of the movements will lend itself (mentally and physically) to certain combinations, if you really struggle with pullups, hitting a set of 45 straight off the bat will really hit you hard.
So what can you learn from the experience or take away to other workouts, a big part of the lesson here is that smaller sets done with less rest can often trump bigger sets with more rest in terms of total output (which is the aim of the game), the key word here is less rest, if you are breaking those 100 wall balls into sets of 5 - that rest better be damn short to be effective! The other lesson (and a super important one) is that you might be capable of more than you realise - did Fran 4.0 in 5min but your Fran 1.0 was 9min? Perhaps you need to switch your brain off when it comes to bigger sets and just go - you are obviously capable of generating the power (the total volume is the same) you just need to push yourself to go there.
Now how do the lessons learned for someone that is high level (3:00 Fran territory) differ? For someone in this territory the results are likely to be a bit more subtle (a few seconds here and there) and they are obviously capable of performing the work in normal Fran unbroken, what becomes a factor in this territory is the amounts of transitions (having to pick the bar up more times / having to jump to the pullup bar more often) and for these guys their time will be affected by how far away they position their bar from the pullup bar (note this is only for people in that 3:00 territory, if you are taking longer than that - the extra walk is just you enjoying some bonus rest)
What is interesting is that someone who is truly “competant” ie they can handle the weight of the thrusters, they are efficient at pullups, have the physical capacity to complete a decent volume of each movement - the rep schedule almost becomes irrelevant, it comes down to efficient of movement and transitions. But the zinger at the end of it all is that someone who is pretty good at CrossFit will more than likely get their fastest time (ie generate the most power) on the classic 21-15-9 rep scheme, the descending rep schedule accounts neatly for fatigue across the 3 sets and allows for maximum speed and total output - maybe there is a little bit of thought behind that seemingly random rep scheme after all?