I Manipulated Rep Speed for 30 Days – Here’s the Muscle Detail – Fitness Volt

Most exercisers lift and lower their weights using a fairly standard rep speed or tempo. This usually involves a 1-2 second concentric (lifting) phase followed by a 1-2 second eccentric (lowering) phase. Some may also add a pause at the top or the bottom of each rep, but many don’t.

While paying so little attention to rep speed doesn’t automatically make a workout ineffective, exercisers who ignore tempo may be leaving gains on the table.

There are several critical training variables you can manipulate to make your workouts progressively more challenging. They include:

• Heavy weights/low reps vs. lighter weights/higher reps
• Number of reps per set
• Sets per muscle group
• Sets per workout
• Length of rest between sets
• Exercise order
• Training frequency
• Training split
• Exercise modality (e.g., machines vs. free weights)

Changing any of these things will alter the feel and effect of your workout. This can help prevent boredom but, more importantly, will ensure you stay clear of the progress plateaus and training ruts that frustrate so many lifters.

Tempo is another variable that you can adjust to keep your training on track. But, considering that your rep speed is almost infinitely variable, it can be hard to know where to start. This may help explain the popularity of the standard 1-2 second concentric/eccentric tempo used by most exercisers—it’s so simple!

In this article, I identify four different tempos and put each one to the test for a week while keeping every other aspect of my training unchanged. The aim? To see which tempo produces the best results.

Tempo Training 101

Before I dive into the details of my 30-day tempo training experiment, let’s first establish what training tempo is and how it might help you.

Tempo refers to how fast or slow you perform each phase of a rep. Rather than working at a random speed, you purposely control every part of the lift: the lowering (eccentric), the pause at the bottom, the lifting (concentric), and the pause at the top.

This isn’t a new concept, and strength coaches and bodybuilders have used tempo prescriptions for decades to improve control, target specific muscle fibers, and increase time under tension—a key driver of hypertrophy (1). That said, it was legendary training expert Charles Poliquin who brought training tempos to the masses.

Related: I Tried Charles Poliquin’s German Body Composition Training for a Month – Here’s What Happened

How to Read a Tempo Prescription

Tempo is usually written as a four-digit code, like 4-1-2-0, and each number refers to a specific part of the rep:

• First number (eccentric phase): Lowering the weight – in this case, 4 seconds.
• Second number (pause at the bottom): Isometric hold – 1 second.
• Third number (concentric phase): Lifting the weight – 2 seconds.
• Fourth number (pause at the top): 0 seconds.

For example, in a bench press, 4-1-2-0 means you’d lower the bar slowly over 4 seconds, pause briefly at your chest, press it up over 2 seconds, and immediately start the next rep without resting.

You may also see an “X” which means explosive/as fast as possible. This tends to crop up in power exercises, usually in the concentric or lifting phase.

Why Use Tempo Training?

When you control your tempo, you take momentum out of the equation and force your muscles to do more work. This can:

• Increase time under tension, stimulating more muscle growth
• Improve mind-muscle connection, especially for muscles that are hard to “feel”
• Build better movement control, reducing injury risk
• Expose and correct technical flaws, such as bouncing out of the bottom of a squat

It’s also a great way to make lighter weights feel heavier, which can be useful if you’re dealing with joint issues, training at home, or simply want to reduce load without sacrificing effort. I often use slower tempos with bodyweight exercises to avoid having to use a weighted vest.

Are There Any Tempo Training Drawbacks?

While tempo training is useful and can be effective, it’s not perfect. Potential disadvantages include:

• It can be mentally and physically demanding, especially if you’re used to a faster pace.
• It’s not ideal for building maximum strength as slower reps reduce force output.
• There’s a learning curve to executing tempo accurately without constantly checking a stopwatch.
• Focusing on your tempo can be distracting, especially if you want to switch off your brain and just lift.

That said, if you’re looking to break out of a training rut, improve your technique, or build muscle with more intention, tempo training is a tool worth adding to your kit.

Related: The “Eccentric Overload” Protocol: I Slowed Down My Reps for 4 Weeks – Did My Strength Explode?

My 30-Day Tempo Training Workout Plan

To better judge the effects of tempo training, I kept every other workout variable the same throughout the four weeks—the same exercises, sets, reps, and split. The only thing that changed was how fast I performed each rep. I also adjusted the load as needed to maintain good form and safely match the prescribed tempo.

This is the program I followed:

Weekly Split

Workout 1: Chest and Back  

1. Bench Press
2. Pull-Up
3. Incline Dumbbell Bench Press
4. Seated Cable Row
5. Cable Crossover
6. Face Pull
7. Dumbbell Pullover

Workout 2: Legs

1. Squat
2. Romanian Deadlift
3. Leg Press
4. Leg Curl
5. Lunge
6. Standing Calf Raise

Workout 3: Shoulders and Arms

1. Overhead Barbell Press
2. Dumbbell Lateral Raise
3. Cuban Press
4. Barbell Curl
5. Barbell Skull Crusher
6. Dumbbell Concentration Curl
7. Triceps Rope Pushdown

Workout 4: Legs (2)

1. Deadlift
2. Front Squat
3. Barbell Hip Thrust
4. Leg Extension
5. Reverse Lunge
6. Seated Calf Raise

Sets, Reps, and Tempo

As this was an experiment to determine which tempo worked best for building muscle, I stuck to the most common set and rep scheme for that goal—3-4 sets of 8-12 reps per exercise. However, I used a different tempo for each of the four weeks.

1. Classic Hypertrophy Tempo – 4-0-2-0
2. Super-Slow Tempo – 6-3-6-0
3. Controlled Power Tempo – 3-1-X-1
4. Paused Precision Tempo – 2-2-2-2

30 Days of Tempo Training: Week-by-Week Breakdown

Each of the tempos provided challenges and benefits. Here’s a breakdown of each training week and how it went.

Week 1 – Classic Hypertrophy Tempo (4-0-2-0)

4-0-2-0 is probably the most widely used hypertrophy training tempo, so it made sense to start my 30-day experiment with it. It emphasizes the eccentric/lowering phase which makes a lot of sense, as studies suggest it’s the main trigger for muscle growth (2).

In addition, you are roughly 1.4 times stronger eccentrically compared to concentrically (3), meaning you can lower more weight than you can lift. The longer eccentric phase lets you tap into this “hidden strength” and makes each rep more effective.

Unfortunately, eccentric contractions are also closely linked to delayed onset muscle soreness, which was the first thing I noticed after using this training tempo. And while sore muscles don’t necessarily indicate a good workout, they did suggest that using this tempo provided a unique challenge.

In addition, training with a 4-0-2-0 tempo strengthened my mind-muscle connection, and I could really feel the target body parts doing all the work. That said, it was a battle not to speed up as fatigue set in.

Summary:

• Muscle Activation & Mind-Muscle Connection: ★★★★☆
• Hypertrophy Potential: ★★★★☆
• Training Enjoyment: ★★★☆☆
• Practicality: ★★★☆☆
• Overall Effectiveness: ★★★★☆

Week 2 – Super-Slow Tempo (6-3-6-0)

Super-slow training was popular in the late 1980s and early 1990s. As the name suggests, it involves lifting and lowering your weights very slowly. This, proponents believe, makes workouts more effective and time-efficient than conventional strength training. There was even a chain of super-slow gyms that may or may not still be in operation.

I’ve used this tempo before when recovering from injury or training around joint pain. The slow tempo means there is much less joint and connective tissue stress, and you are all but forced to use very light loads. For me, this meant slashing my training weights by close to 50%.  

While I could feel my muscles working during my week of super-slow training, such a controlled rep speed sucked the fun out of my workouts. Sure, there was very little joint stress; but it also meant that I had to focus hard on counting and clock-watching rather than having an enjoyable, fulfilling workout.

So, while super-slow reps can be useful, you’ll need to adapt your mindset to training in such a controlled fashion. For me, at least, the juice wasn’t worth the squeeze!

Summary:

• Muscle Activation & Mind-Muscle Connection: ★★★☆☆
• Hypertrophy Potential: ★★☆☆☆
• Training Enjoyment: ★★☆☆☆
• Practicality: ★☆☆☆☆
• Overall Effectiveness: ★★☆☆☆

Week 3 – Controlled Power Tempo (3-1-X-1)

3-1-X-1 is my favorite training tempo and the one I tend to revert to when not using another prescribed rep speed. The 3-second eccentric and 1-second pause set the stage for the explosive concentric (“X”), which made every rep feel purposeful and athletic.

Unlike super-slow training, this style added a dynamic element that put some much-needed energy and enjoyment back into my workouts.

I kept the loads moderate to avoid letting the “X” turn into a sloppy cheat rep. That explosive effort had to come from muscle, not momentum. The short pause before each lift helped reinforce proper positioning and control—especially for compound lifts like squats and presses; it made sure I didn’t try and bounce the weight up.

This tempo also gave me a strong mind-muscle connection without sacrificing intensity. Each set felt more focused and aggressive, and I noticed better bar speed and even a small bump in strength by the end of the week.

Bottom line? This tempo prescription offered the best of both worlds—control and explosiveness—and was easily the most enjoyable tempo of the four. Studies also suggest that this is probably the best tempo for hypertrophy and strength gains (1).

Summary:

• Muscle Activation & Mind-Muscle Connection: ★★★★★
• Hypertrophy Potential: ★★★★★
• Training Enjoyment: ★★★★★
• Practicality: ★★★★☆
• Overall Effectiveness: ★★★★★

Week 4 – Paused Precision Tempo – 2-2-2-2

If you appreciate a deep pump and muscle burn, the 2-2-2-2 tempo delivers. With no rest at any point during the rep, the tension never lets up—and my muscles felt it. The double pause—at the bottom and top—eliminated any chance of momentum creeping in, while the steady 2-second lift and lower ensured the target muscles stayed under constant stress.

That uninterrupted time under tension made even lighter weights feel heavy fast. But like with super-slow training, the need to count and intently focus on the timing took some of the fun out of lifting. I wasn’t just training—I was monitoring.

That said, if your goal is to maximize time under tension and perfect your exercise technique, 2-2-2-2 will get the job done. Just don’t expect it to be the most enjoyable workout.

Summary:

• Muscle Activation & Mind-Muscle Connection: ★★★★☆
• Hypertrophy Potential: ★★★★☆
• Training Enjoyment: ★★☆☆☆
• Practicality: ★★☆☆☆
• Overall Effectiveness: ★★★☆☆

Closing Thoughts

You don’t need to grind through painfully slow reps to build muscle or strength. While ultra-slow tempos have their uses, they can turn what should be an enjoyable workout experience into something you’ll come to dread.  

For most lifters, a moderate pace with controlled eccentrics and explosive concentrics—like the 3-1-X-1 tempo—provides the perfect balance between tension, technique, and training satisfaction. But don’t take my word for it—experiment and see what works best for your goals training and style.

Tempo is a powerful tool hiding in plain sight. Use it intentionally, and your workouts may never feel the same again.

References:

Fitness Volt is committed to providing our readers with science-based information. We use only credible and peer-reviewed sources to support the information we share in our articles.

1 – Wilk M, Zajac A, Tufano JJ. The Influence of Movement Tempo During Resistance Training on Muscular Strength and Hypertrophy Responses: A Review. Sports Med. 2021 Aug;51(8):1629-1650. doi: 10.1007/s40279-021-01465-2. Epub 2021 May 27. PMID: 34043184; PMCID: PMC8310485.

2 – Schoenfeld BJ, Ogborn DI, Vigotsky AD, Franchi MV, Krieger JW. Hypertrophic Effects of Concentric vs. Eccentric Muscle Actions: A Systematic Review and Meta-analysis. J Strength Cond Res. 2017 Sep;31(9):2599-2608. doi: 10.1519/JSC.0000000000001983. PMID: 28486337.

3 – Nuzzo JL, Pinto MD, Nosaka K, Steele J. The Eccentric:Concentric Strength Ratio of Human Skeletal Muscle In Vivo: Meta-analysis of the Influences of Sex, Age, Joint Action, and Velocity. Sports Med. 2023 Jun;53(6):1125-1136. doi: 10.1007/s40279-023-01851-y. Epub 2023 May 2. PMID: 37129779; PMCID: PMC10185641.