Strength training: the BIG positives of negatives!

What is 'eccentric training' why is it effective, and how can athletes incorporate it into a training routine? Andrew Hamilton provides the answers

Guilt is a funny thing. It’s one of those emotions that can keep coming back to haunt you, long after you’ve dealt with the situation. Like all erring human beings, I’ve had my fair share of guilt to contend with and remember especially one time as an enthusiastic but rather inexperienced fitness instructor. After being goaded about my programming and our gym equipment on several occasions by a particularly arrogant and unpleasant 80s Yuppie, I decided to deploy the nuclear option from Arthur Jones’s training philosophy, and he was duly invited to undergo a one-to-one ‘negative’ training session. It worked – rather too well in fact. Not only did his post-workout complexion resemble the colour of whites that have accidentally been boil-washed with a cheap pair of denims bought from the market, we never saw him in the gym again – ever! That experience taught me two things; 1) Always let smart-ass comments wash over you and 2) Never underestimate the effects of negative training!

What is eccentric training?

So what is this negative training thing then? Well, imagine picking up a dumbbell and curling it upwards as you would in a biceps curl. If you watch your biceps muscle, you’ll see it contract and shorten while force is being exerted to raise the weight during this ‘lifting’ phase. When muscle fibers shorten and contract as they exert force, the muscle contraction is known as a CONCENTRIC CONTRACTION. Think of the parts of resistance exercises you perform in the gym where the weight is rising against the force of gravity – the muscle contraction is concentric or positive. For most people, this is what they think of as the ‘useful’ part of the movement.

However, there is another type of muscle contraction that can occur. Known as an ECCENTRIC or NEGATIVE CONTRACTION, this movement occurs when the muscle fibers are being lengthened under load. In the example of the biceps curl, the negative or eccentric contraction occurs if the dumbbell is lowered slowly and under control - the biceps muscles having to exert force to stop the weight falling freely.

Why eccentric training?

Research has shown that both the positive (concentric) and negative (eccentric) contractions in resistance training confer strength gains to the muscles. However, more recent studies have demonstrated that eccentric contractions are particularly effective in this respect^(1-3). This is because the physiological ‘micro-damage’ induced in muscle fibers after eccentric muscle contractions strongly stimulates the release of a signalling molecule called ‘mTORC1’ – and thanks to the advances in molecular biology, we now know that mTORC1 switches on genes in muscles, instructing them to grow.

In the gym, almost all resistance exercises will consist of a lifting or positive contraction followed by (hopefully) a lowering or negative contraction. However take a look round many gyms and while you’ll see people performing the positive parts of the exercises OK many are failing to perform the negative phase of the exercise. By dropping the weights quickly (easy to spot by all the crashing and banging going on!), many people end up throwing away a significant proportion of the potential training benefits available when BOTH positive and negative phases are emphasised. Not only will each set be less effective, more sets and therefor more time is needed to thoroughly work the muscles, which also reduces the intensity of the workout.

This accounts for the ‘two up, four down rule’ when performing repetitions of an exercise correctly. By counting “1, 2” as you lift the weight and “1, 2, 3, 4” as you lower the weight you allow enough time on the lowering phase to generate a full negative contraction. The correctly performed resistance training session will therefor work the muscles both concentrically and eccentrically.

Higher loads

Your muscles can sustain more force on a negative contraction than on a positive one. This is why you can sometimes just manage to lift a very heavy object down from a high shelf only to find you can’t lift it back up again without assistance. ‘Eccentric training’ sessions draw on this extra ‘negative strength’ to try and boost overall muscle strength and work in the following way. In a normal workout, the amount of weight you select should be determined by how many repetitions of an exercise you can perform using strict form. However this number is in turn limited by the fact that you cannot lift as much weight as you can lower. This means that when you reach ‘failure point’, it is always during the positive or lifting phase of a rep, never on the negative or lowering phase. The result is that even the strictest workouts emphasise and develop positive or concentric strength. But it doesn’t have to be this way.

In an eccentric training session, the emphasis is shifted from the away from positive contractions and onto to negative contractions. In order to achieve this, the amount of weight you lift is increased by between 25 and 50% and a training partner assists you by supplying some help during the lifting phase only. At the top of the lift, he or she stands back while you lower that extra weight nice and slowly, really working the muscles through a thorough negative phase of movement. At the end of the lowering phase, the training partner again helps you to lift through the positive phase and then leaves you to lower on your own (remember, you’ve more strength in a lowering phase than lifting). This is repeated for 8-10 reps until a set is completed. In the example of biceps curls above, your partner would help you to curl the barbell/dumbbell (or handles if using a machine) into the fully contracted position where the palms of the hands are opposite the shoulders and then allow you to lower the weight steadily and slowly.

What to expect

You don’t get ‘owt for nowt as they say and if you haven’t trained like this before, you’re in for a shock! Expect to feel totally jellied, especially for the first couple of sessions. You’ll also notice more soreness and stiffness the day after than usual because negative contractions cause more of the microfilament damage thought to be responsible for post workout soreness than do positive contractions. Remember though, this is a ‘good’ thing as it’s the micro-damage that stimulates muscle growth via mTORC1.

With the above in mind, it’s wise to limit your negative sessions to no more than a couple of sets per body part or to just add one negative set after your normal sets. These same reasons also make negative training unsuitable for beginners. However, don’t be put off by these caveats, because used sensibly negative training can help to produce dramatic gains in strength, especially for those with some experience under their belts. Throwing in some negative training can also help you get over those sticking points when you feel as though you’re ‘stuck in a rut’ or you need something to lift your intensity and having a partner to assist you can be very motivating. Just remember not to try it out on the unsuspecting unless you’re prepared for a major guilt attack!

References

1. PLoS One. 2018 Jun 12;13(6):e0199050
2. Front Physiol. 2019 Apr 18;10:406
3. Muscle Nerve. 2016 Nov;54(5):914-924