How To Use Tonal Eccentric Mode For Your Workouts (Explained)

One of the smartest things you can do to build more muscle on Tonal is to use eccentric mode. Today I will clarify what is eccentric mode, how it works, and most importantly, how to use it to gain muscle and burn more fat (plus, when you should avoid it).

As a whole, the Tonal eccentric mode is a dynamic weight mode that automatically adds more resistance to the negative phase of the movement. Tonal allows adding up to 60% of the weight during the eccentric phase, which helps to induce greater mechanical tension on the muscle and maximize the effect of resistance training.

However, there is a big difference between the Tonal eccentric mode and the traditional eccentric training (which I also explain in a moment).

What Is Eccentric Mode?

The Tonal eccentric mode is nothing new. It is a smart feature that is based on the eccentric training principles (also called negative training) that have been first introduced by Erling Asmussen in the 1950s.

What is eccentric training? In short, eccentric training works by creating muscle contraction while it is lengthening under load. Eccentric contractions play an important role in everyday movements, as well as mobility, coordination, and force production in the muscle.

What is the difference between concentric and eccentric exercise? Overall, the concentric exercise is when the activated muscles shorten (e.g. lifting the leg up shortens the hip flexors or pressing on the bike pedal shortens the quadriceps). Eccentric exercise occurs when the activated muscle is lengthened.

Eccentric contractions are normally used in movements to decelerate, stop, or absorb energy (e.g. downhill walking).

Which Is Better Concentric Or Eccentric?

In general, studies have shown that eccentric exercise is better than a concentric exercise in stimulating gains in muscle strength and mass. Both computerized tomography and magnetic resonance imaging (MRI) showed that eccentric contraction leads to increased muscle cross-sectional area.

Of course, you should not stop your regular workout and focus only on the eccentric part of the lifts. They both are important when it comes to strength and muscle size.

(I will cover later when is the best time to use Tonal eccentric mode).

There are three main modalities of eccentric training:

  • Isokinetic eccentric exercise
  • Isoinertial eccentric exercise
  • Isoweight eccentric exercise

Today, the use of eccentric training has exploded, mainly in rehabilitation, sports performance, as well as strength and conditioning.

For example, Dr. Håkan Alfredson from the University Hospital of Northern Sweden in Umeå reported a 100% success rate in 15 recreational athletes after a 12-week eccentric training that’s been treated for chronic Achilles tendinosis.

Not only that.

This advanced training method allows for generating more muscle tension while using less metabolic energy (very low energy cost, typically 4 to 5 times lower than concentric muscle work) which makes it an effective tool in rehabilitation and injury prevention.

A great example of using heavy negatives are Nordic hamstring exercise for hamstring strain or heel drop exercise for Achilles tendinopathy, which are both effective.

Dr. Myles Calder Murphy from the University of Notre Dame in Australia documented that “heavy eccentric calf training is superior to natural history, traditional physiotherapy, sham interventions and other exercise interventions for improvements in pain and function in mid-portion Achilles tendinopathy” (Murphy et al. 2019).

As you can see, eccentric training is a very effective tool not only to build strength. It is also used as the primary treatment for the elderly, as well as the main training method used by astronauts during long-term space travel to prevent muscle and bone density loss.

NOTE: You can learn more about how to use “tonal for weight loss” in my article here.

What Is Tonal Eccentric Mode?

In general, the Tonal eccentric mode is a feature that uses patented technology and AI algorithms to automatically add more weight during the lowering part of the lift. Integration of this training method in most of the workouts not only helps to improve strength but also leads to muscle hypertrophy.

What does eccentric mode mean? The eccentric mode comes from the word “excentric”, which combines two words; ex means “from or away” and centric, which means “center”. Eccentric mode means muscle “contraction” that moves away from the muscle’s center.

Eccentric exercises are exactly that; they are slow, lengthening muscle contractions that are for a specific muscle.

The difference between regular eccentric training and Tonal eccentric mode is that traditional eccentric training either increases the time under tension or increases the resistance for the negative part of the exercise.

  • Eccentric with tempo – Traditional eccentric training works by slowing down the tempo of the negative part of the movement, which helps to increase the time under tension. For example, 1 second on the lifting phase followed by 5 seconds tempo on the lowering phase.

See the graph below.

As you can see, in the illustration above, the concentric phase of the lift takes significantly less time the eccentric phase (graph on the right side). This additional time that muscle is under the load leads to substantial strength gains (Guilhem et al. 2010).

  • Isoweight eccentric training – In the world of bodybuilding and fitness, the most commonly used is isoweight eccentric training, which works by adding a high load and performing only the negative phase of the lift (of course this requires a training partner).

See below.

An example of this training would be when your workout buddy is lifting the weight (so he is kind of doing the concentric phase for you) and all your work is to control the movement during the lowering phase.

You don’t lift the weight up. You just control it down.

How Does Tonal Eccentric Mode Works?

As a whole, the Tonal eccentric mode works by adding the resistance (up to 60% more than your normal resistance) for every repetition, while keeping the resistance during the concentric phase without any changes.

See the graph below.

As you can see, the Tonal eccentric mode works kind of like asking your 40lbs dumbbell to become a 55lbs dumbbell, but only for the negative part of the movement.

Tonal uses accelerometers in the handles and power output sensors to “know” when you finish each phase. It takes up the data, feeds it back into the computer and the digital resistance automatically switches 40lbs weight into 55lbs.

To be honest, the first time I used eccentric mode I was really blown away because I’ve never seen other fitness equipment that can adjust the weight for you (you can tell some real exercise enthusiasts were involved in this project).

How To Use Eccentric Mode On Tonal?

Overall, you can use eccentric mode on Tonal, as well as other dynamic modes, during the Free Lift mode where you choose your own exercises. You can turn the eccentric mode at any time during the lift. Plus, Tonal also incorporates eccentric mode into their on-demand workouts and programs.

Here is how to prepare and use Tonal eccentric mode:

  • Use with one or two exercises – Think about one or two lifts where your strength has plateaued. Please remember that eccentric mode on Tonal is an advanced training method, which means you should not use it for every exercise. That’s why I would strongly recommend choosing 1-2 exercises per workout where you really want to focus.
  • Use it intermittently for a couple of weeks – You want to use Tonal eccentric mode ideally during the strength and hypertrophy phases of your workout plan. Ideally for 2-3 weeks every month. Do not use it for your endurance or deload period where you spend a week on recovery.
  • Use progressive overload from week to week – If you plan to use eccentric on week 1 with 20% more than your concentric lift, add extra resistance for week 2 (around 2.5-5% more than a week before, depending on your strength level). Once week 2 is finished, take a week off for recovery.

I know that some of the Tonal workout programs already include an eccentric mode for all of the exercises within one session. However, I don’t think this is a good idea, especially for beginners.

Please remember that the Tonal eccentric mode is an advanced method and does put extra stress on your body. This means you want to be well-rested when you do it.

Extra training stress can lead to excess fatigue and reduce training quality later on in the upcoming weeks.

NOTE: Click here to learn more about what are the best “tonal workouts” for fat loss and muscle mass.

How To Combine Eccentric Mode On Tonal?

In general, you can combine the Tonal eccentric mode with other dynamic modes like spotter or burnout mode. You can also use other techniques like bilateral position change and tempo to add more variety and hit the muscle more without extra weight.

You can learn more about how to use “tonal burnout mode” for health and weight loss in my article here.

Here are some of the ways that will hopefully inspire you to experiment with this cool feature.

  • Tonal eccentric + slow tempo – For the best results, you can use the Tonal eccentric mode together with increasing the time under tension. This means you not only add more resistance for the negative phase but also significantly slow down the tempo.
  • Tonal eccentric + position change – You can use eccentric mode in a way to you use both limbs (bilaterally) for the concentric phase (e.g. going up with squat) then immediately move the leg back and change position into the lunge. Now you not only load more weight but also changed the movement into unilateral.
  • Tonal eccentric + handle change – Here you can use eccentrics in a way that you do lift using the pronated grip and you lower the weight with a supinated grip. For example, doing a seated pull-down in the concentric phase (lowering the smart handles towards your chest), then you supinate your wrists and perform chin up on the way back.

NOTE: Click here to learn more about “tonal leg workout“.

When To Use Tonal Eccentric Mode?

In general, the best time to use the Tonal eccentric mode is when you’ve been stuck with your progress or when you’re at the beginning of your training cycle. For compound lifts, use eccentric mode at the beginning of your workout. For isolation and accessory exercises use eccentric mode at the end of the workout.

When not to use Tonal eccentric mode? You should not use the Tonal eccentric mode on the days when you feel tired and fatigued. You should also skip this mode when your goal is to build strength, without adding extra muscle size. For strength gains without extra muscle is better to focus on the concentric phase of the lift.

Is Tonal Eccentric Mode Effective?

In general, the Tonal eccentric mode is effective because it generates greater maximal tension and it has a lower metabolic cost for the same work produced, which tends to be more effective to stimulate gains in muscle strength, compared to traditional training.

Not only that.

Using a Tonal eccentric mode overloads the muscle and helps them grow in a way that also translates into better strength with exercises.

Jeremy M Sheppard from Canadian Sport Institute documented sixteen volleyball players who performed eccentric resistance training over the course of 5 weeks, 3 times per week.

The results showed that “the eccentric accentuated training group improved jump performance by 11% whereas there was no effect (−2%) in the control group” (Sheppard et al. 2008).

Tonal Eccentric vs Smart Flex

Apart from eccentric mode, Tonal has also a number of other cool features that helps you optimize your workout.

The difference between the Tonal eccentric mode and smart flex is that the eccentric mode adds more resistance to the negative part of the movement, without changing the concentric resistance.

On the other hand, the Tonal Smart Flex mode is the feature that measures your power output from every repetition and adjusts the resistance (either add more or reduce) based on your current performance.

I like to use smart flex mode because when it detects that I can handle more weight, it will add more resistance for both eccentric and concentric evenly.


As you can see, the Tonal eccentric mode is a great tool to build muscle and strength because it allows you to add resistance to the negative part of a movement. Adding more weight increases force production and induces more mechanical tension in the muscle.

I love to use this mode in combination with other smart features like burnout mode or chains, as well as other variations that I’ve mentioned above.

Michal Sieroslawski

Michal is an exercise physiologist (MSc), nutrition coach, Ashtanga teacher, and fitness blogger. He shares his successes and failures to help busy men and women squash down 20, 50, or even 100 pounds of fat without leaving their home.

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