If you’re intending to build muscle through a weightlifting program, then it’s important to consider not only which exercises you’re using but also how you’re using them. Things like form and intensity are often more important than the precise exercises themselves and this can be easy to overlook for someone who’s new to working out and probably eager to get going.
One of the most important aspects to consider with regards to form, is the speed at which you are performing each repetition. While this is something that many people won’t consider until they’re already quite advanced with their training, it is nevertheless a highly important factor that can make a huge amount of difference to the effectiveness of your program.
The tempo of any exercise, or the ‘cadence’, can be written as a serious of three numbers such as: 3-1-2. These numbers denote in seconds just how long you are taking on the positive and negative portions of the movement, as well as how long you are pausing at the top. In some cases you might see this written as four numbers (for instance ‘3-1-2-1’) which includes the rest between repetitions.
The positive portion of your movement is also known as the ‘concentric portion’ and is the part where the muscle is shortening – when you bring the dumbbell up in the bicep curl for instance. Meanwhile, the eccentric portion is the negative portion and is the part where the muscle is lengthening – such as lowering a dumbbell during a curl. Often the ‘positive’ portion is the first part of the movement and the ‘eccentric’ is the latter – though this won’t always be the case.
By switching up the speed of both the positive and eccentric phases of a movement, as well as the pause at the tops and bottoms of each repetition, you can thereby alter the effect of the exercise and potentially see huge benefits in terms of strength and growth.
Using a slow, 5-1-5 tempo, you can potentially increase hypertrophy (muscle growth) considerably through a number of mechanisms.
Firstly, by using a slower cadence, you are effectively increasing your ‘time under tension’ (TUT) which is considered by many bodybuilders to be the single most important variable in encouraging growth.
Time under tension of course refers to the amount of time that you spend actually straining against the weight that you’re lifting. In effect this is part of any workout that actually has an effect – as opposed to the time you spend setting up or pausing between workouts. Thus, by increasing your tempo, you can thus increase time under tension and as far as your muscles are concerned this will be the equivalent of having had a much longer workout in terms of pure effort.
Using a slower tempo also has several other advantages. For instance, it allows you to focus more on the movement and to thus increase your ‘mind-muscle’ connection. This is a factor that many bodybuilders believe allows them to increase their effort on each workout and to more fully engage their muscles, triggering more growth.
Finally, using a slower tempo can also help you to improve your technique, involving more of the smaller supportive muscle groups in order to steady the weight and ensuring you can’t ‘cheat’ your way through any portion of the movement by using momentum. With time, practicing using a slow tempo can increase stability and control in all your lifts.
Using a fast, explosive tempo on the other hand allows you to engage the fast twitch muscle fibers. These are the muscle fibers that are most responsible for explosive strength and power and they are the fibers we engage whenever we need to use 100% effort. They are also the larger, thicker muscles that create a more ‘built’ muscular frame.
In order to recruit fast twitch muscle fibers in any exercise, you need to exert maximum force. This is created both by the weight you are pushing/pulling against and by the speed of the movement. Simply by performing repetitions more quickly, you will thereby be generating more force and you will be engaging more fast twitch muscle fibers improving your strength and potentially adding to your size.
Using faster repetitions also makes a workout more energetic, thereby helping you to burn more calories.
Using Both in Conjunction
Some people highly recommend the use of slow repetitions in order to build more muscle size, while others advocate using rapid repetitions as the best way to increase strength and thus muscle. Others still suggest that there is no benefit to using either method (1).
One fairly common ‘compromise’ position states that we should use very fast repetitions on the positive portions of the movements and very controlled, slow eccentric movements. The idea here is that you recruit your explosive muscles in order to lift and accelerate the weight, but then get to slowly lower the weight engaging the slow twitch muscle fibers during the negative portion of the movement. You can also incorporate ‘static’ strength by holding the weight in position at certain points during the negative portion of the movement.
Generally our ‘negative’ strength is much greater than our positive strength and we also have more endurance in this capacity. It’s also thought that the eccentric and static contractions are the ones that are able to create the most microtears and trigger the most growth. By increasing your amount of time in that portion of the movement then, you might be able to encourage more growth and more endurance without sacrificing the explosive power gained from rapid concentric movements.
It might be worth noting at this point that Bruce Lee famously used a lot of static contraction in his training. And he had one of the greatest strength-to-weight ratios of all time.
Another benefit of using a combination of both fast and slow repetitions in this manner, is that everybody has a slightly different makeup when it comes to their muscles. Some people have more slow twitch muscle fiber relative to fast twitch and others have the opposite situation. While it is possible to convert fiber types, this only appears to occur to a small degree and over a long period of time. Thus, someone with more slow twitch muscle fiber may actually benefit more from slower contractions – as they’d be targeting the fiber types they have more of. This may also account for some of the different results found by researchers.
Depending on who you listen to, there are some great benefits to using slow repetitions, fast repetitions, static contractions or slow negatives… so isn’t the safest approach just to build all of them into your workouts and gain all the advantages as a result?