Today I’m going to break down some of the pros and cons of training with either a set number of reps or for a set amount of time. When you train for a set number, an instructor assigns a set amount and everyone attempts to do that amount. When you train for a duration, the instructor sets the time and everyone attempts to go until the timer stops. Both of these have advantages and disadvantages, and we’ll go in depth below.
The advantage of performing a set number of reps is that it is standardized. If everyone does 5 kicks off each leg before moving on, you assure that everyone gets an equal amount of practice in. The same is true for push ups or any other exercises you incorporate into class. Training by the numbers also encourages goal setting. If class starts and everyone has to do 25 push ups, some students will be motivated to work towards that goal.
The disadvantage to this approach is the “one size fits all” mentality it requires. 5 kicks off each leg is a good standard, but beginners might need more time and reps to really learn something before moving on. Additionally, an advanced student could fire off 5 kicks very quickly, and then be standing around doing nothing while they wait for the rest of the class to catch up. This creates wasted time.
Another downside is the intimidation factor. 25 push ups is a lot for a de-conditioned beginner. Most students starting martial arts are not capable of this. Some will rise to the challenge, but others will think it’s an impossible goal. When a set amount is required, people who can’t physically perform that many reps might lose motivation.
The number one advantage of doing an exercise or drill for a set amount of time is that everyone can work at their own pace. If you tell a white belt and a black belt to kick a bag exactly 10 times, they both will. If you tell them to kick the bag for 30 seconds, the black belt will kick the bag many more times than the white belt. Similarly, with push ups a beginner given 30 seconds will do what they can while an advanced student would be expected to do more. This approach lets beginners begin, and advanced students go harder.
The drawback to timed exercise is that some people will never push themselves. If you tell a beginner to do push ups for 30 seconds they might do 10 that class… and then 10 the next class… and then 10 the class after that… Some people need to be pushed to improve. Without an external force demanding more of them, they never go above what they could already do.
Even a beginner with the best of intentions may struggle if the duration is too short. If you show a student something new then give them 30 seconds to a minute to practice, they might not have enough time to do enough reps to reinforce the concepts. When doing timed segments, the instructor has to be much more involved – both in motivating students to push themselves and in making sure beginners have enough time to really learn.
There’s a Time and Place for Both
Some drills work better done one way than the other. Is everyone hitting the bag as hard as they can doing techniques they know? Time it and let them go nuts. Have a class where several people only do a few push ups? Set a goal to make them push themselves. In a perfect world, everyone would have the goal to do “one more than last time,” but in reality some people need motivation. An instructor’s job is be the cheerleader (or drill sergeant) who figures out how to use these tools to push students to improve.