I am sure you have heard various bodybuilding experts lecture you on the importance of tempo. If you’re not familiar with the concept, tempo is simply the speed at which you perform a repetition. It is often written with four numbers such as 4-1-1-0 which means you lower the weight for 4 seconds, pause for one second, lift the weight for 1 second, then pause for 0 seconds.
While this is an interesting idea that allows you to account for an often forgotten variable (rep speed), it is distracting to use during training. If you train by yourself then you have to constantly be counting in your head, which takes your mind off of the effort at hand. It’s pretty hard to get amped-out about a set and then have to count to yourself!
Even as a strength coach I find it distracting when I am training an athlete. By counting for the athlete I take the burden off of them, but it prevents me from giving helpful cues and coaching points to the athlete during the set.
Simply put, although useful, it’s a pain in the ass to use tempo prescriptions!
Luckily, there is an alternative: timed sets.
This is not a new concept, but it is one that I haven’t seen written about extensively.
It’s basically what it sounds like. Instead of counting reps you count how long each set takes. While this doesn’t give you the precise control over each repetition that tempo prescriptions do, it does give you many of the same benefits.
You may have heard of the concept of “time under tension.” This concept basically states that it is the amount of time the muscles are under tension that determines the result of the training. This is the concept we are building on here. Basically, different lengths of time will lead to different results.
Time = Outcome
10 seconds = maximal strength and power
10-20 seconds = functional hypertrophy
20-40 seconds = mixed hypertrophy
40-60 seconds = sarcoplasmic hypertrophy
60+ seconds = muscular endurance
As you can see, sets less than 10 seconds in duration will lead to the development of maximal strength when heavy loads (80%+) are used, or the development of power when lighter loads are used (70%). Sets lasting 10-20 seconds will develop functional hypertrophy, which is the growth of the actual muscle fibers, whereas sets of 40-60 seconds will develop sarcoplasmic hypertrophy, which is the growth of the other components of the muscle (not the muscle fibers themselves). Sets lasting 20-40 seconds will provide you with a mixture of the two types of muscle growth.
Choose the time range appropriate for your goals and give it a shot. You may be surprised how many (or how few) reps you get in a given time frame. I find that strength and power athletes have a tendency to do their repetitions rather quickly, so when training for hypertrophy the typical “8-12 reps” may put them in the “functional hypertrophy” zone instead of the “mixed hypertrophy” zone. With endurance athletes I have observed the opposite phenomenon.
Timed sets are a great concept, especially for those involved in sports, as it emphasizes speed of execution in order to get the greatest number of reps in the timeframe as possible. As you know, speed of movement is more important in most sports than just about anything else. But even if you are not training for a sport where speed is important, emphasizing the speed of repetitions leads to a greater activation of fast-twitch muscle fibers which have a high potential for strength and muscle growth.