Muscle growth is based on a lot of different variables (such as you diet and what exercise you perform etc) But tempo itself is something that is overlooked a lot when it comes to strength training (or perhaps not understood).
People in a gym setting generally either conduct slower or faster pace, depending on their program structure. Both techniques play their own part in progressing with your goals.
It’s interesting that you have asked the benefits and negatives of both mediums. Let’s delve into this a bit further, gathering some bits of research I’ve come across from various sources.
Slow reps for muscle growth.
- Slower tempos benefit the muscles because they spend a lot more time under the tension of the weight. The muscle is actually straining for an extended period of time through the repetitions (and overall set). This in fact recruits a higher threshold of motor units that trigger useful strength and fiber size adaptations.
- Slower movements with lighter weight for novice trainees is a great starting point in the beginning. Proper technique is essential when starting out, in order to minimise and injuries.
- This is great when recovering from injury as it provides extra blood flow to the effected area.
- Very slow lifting lifting is insufficient in stimulating or activating the higher threshold that type 2 muscle fibres need in order to increase muscular growth
- Slowness has the inability to tap into the calorie torching effects of continuously faster repetitions
- Inability to perform the repetitions needed for adequate muscle growth
Fast reps for muscle growth.
- Perform more reps with heavier weight than you can with the slower tempo. Think of how hard it is to continuously perform your sets with a weight that’s a lot heavier. It becomes impossible because of fatigue.
- When using fast reps, the general idea is to perform as many repetitions, at a particular set time. This could mean 40 + of bicep curls in one minute. It becomes a race against time to get the numbers in.
- Research suggests that despite the lack of time under tension for faster tempo, it does not hinder any muscular growth.
- The ability to lift heavier loads by using a faster tempo enables greater overall recruitment of muscle fibres, especially type 2. This therefore leads to greater overall activation of the targeted muscles.
- Lifting with a tempo between 2–6 seconds is said to promote maximum muscular growth
- Best suitable for power and strength
- Can create an environment for injury if you are not using proper form or are becoming lethargic from the higher volume
- Easy to ‘cheat’ the movement by not performing the full range.
- Can become quite taxing on the nervous system overtime
- Can lead to over-training
From this I would recommend you use both to recruit different muscle fibres, and provide you with a point of difference in your training. This way, you can train for both hypertrophy and strength during different intervals. It’s important to use different methods in your training, as our bodies tend to adapt very easily. Both of these methods have strengths and weaknesses, therefore, keeping that in mind, construct your strength training program accordingly and have fun with it!