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Complex training is a strength training method that is prominent in many strength and conditioning programs.

Using this method, we can target both ends of the force-velocity continuum which allows us to comprehensively develop rate of force development and power qualities.

Despite the literature primarily examining this training method in athletics and team sports such as rugby and basketball, there are significant benefits that can be derived from complex training that will enhance a boxer’s performance.

Therefore, the main points this article will discuss are:

An outline of complex training and how it is applied by strength and conditioning practitioners.

The benefits associated with complex training in terms of athletic performance.

How complex training adaptations can improve boxing performance.

The considerations to account for when implementing this training method with boxers and how we use complex training at Boxing Science with our boxers.


Complex training is considered a valid training strategy for developing high levels of speed and power.

This training method involves performing a set of a high load, low velocity exercise followed by a set of a low load, high velocity exercise.

For lower body complexes heavy back squats are often paired with a jumping or plyometric type movement whereas for the upper-body, complex pairs usually entail a heavy press followed by a medicine ball throw or even a bench press throw.

Though similar to contrast training, these methods should not be confused as complex training means that both types of exercises are performed consecutively in a ‘Complex Set’ rather than performing all sets of the high force lift and then performing the prescribed number of sets for the high velocity lift.

The main benefit of this training method is that it enables the athlete to gain a potentiated response from high force exercises and apply this heightened neural drive to the high velocity/low force movement, and thus display greater rates of force development and impulse.

Combining these two types of movements allows us to target both ends of the Force-Velocity spectrum, shifting the curve to the right and therefore creating a stronger, faster and more explosive athlete.


A review of complex training in the early 2000s concluded that the combination of weight training and plyometric training was just as effective as the conventional configuration of both types of exercises.

However, the author also noted the potential acute response that could be attained in terms of improved jump and medicine ball throw performance.

Since then, research has continuously investigated the effects of this training method in sports such as basketball, soccer and rugby.

Compared to a standard weight training program, complex has been shown to induce greater improvements in squat jump height and countermovement jump height in basketball players.

Similarly, in an investigation of the application of complex training in youth athletes, it was concluded that this training method represented a time-efficient approach for improving jump, sprint and anaerobic performance.

Additional research has observed similar benefits in measures of both upper and lower body rate of force development among volleyball, rugby and soccer athletes.

A more recent review of the literature, in 2014, concluded that complex training is an effective training method for improving strength, power and speed, however whether it is superior method to conventional training methods remains uncertain and it is ultimately at the coach’s discretion to select the training methods that are most applicable to their athletes and their environment.

Taken from Mihalik et al. (2008), demonstrating the improvements in jump height that can be gained from complex training in a short time frame.


From both practical and empirical evidence we can see the potential benefits of complex training for improving strength and speed characteristics in an array of athletes.

But what are the mechanisms behind such improvements?

It appears that adaptations derived from complex training are predominately neural in nature, meaning the nervous system becomes more efficient at producing large amounts of force in a short period of time.

This is primarily attributed to the potentiation effect experienced following high load exercises, facilitating improved performance in the plyometric activity.

This potentiation effect is characterised by enhanced high threshold motor unit activity, improved motor unit synchronisation and firing frequency as well as reduced neural inhibition by the Golgi Tendon Organs. This heightened neural drive is then carried over to the high velocity movement in which the athletes can display greater performance and thus achieve significant training adaptations.

Biomechanically, it has also been theorised that the performance of heavy, near maximal lifts (3-5 repetition maximum) can acutely improve leg stiffness and ground contact time, thus improving stretch shortening cycle (SSC) activity which can have a positive impact on explosive movements that recruit SSC functions such as sprinting and jumping.

Repeated exposure to bouts of higher neural output serves a potent stimulus for improving muscle strength and power characteristics and therefore have a considerable impact on athletes ability to perform explosive actions.


With any strength training method there are certain considerations that must be accounted for in order to optimise its application and complex training is no different.

The consideration we will be discussing include: load, rest time between exercises, the athlete’s strength level and exercise selection.


The load used in the high force movement needs to be sufficient enough to induce a high level of neural activation whilst avoiding exposing the athlete to excessive fatigue.

For lower body lifts it seems that loads ranging from 85%-93% 1RM are most effective in terms of improving performance in the subsequent plyometric exercise.

In contrast, there is an argument that similar loads during upper body lifts result in undesirably high levels of fatigue and therefore it is recommended that loads equivalent to 65%-75% 1RM are most appropriate for upper body complexes.


It is difficult to determine the most optimal rest time duration for complex training as it tends to vary depending on the type of exercise used and the athlete’s strength level/tolerance to high loads.

Due to heavier loads being used in lower body lifts compared to upper body, more rest may be needed between exercises of a lower body complex.

For lower body complexes an intracomplex rest interval of 3-4 minutes is recommended, meaning that the high force lift is performed and is then followed by a rest period of 3-4 minutes before performing the high velocity/plyometric activity.

Using heavier loads on the upper body lifts (87% 1RM), previous research has recommended similar and even longer rest periods between exercises (4-8 minutes), however, at Boxing Science we have found 60-120 seconds rest between upper body presses at 65-75% 1RM and medicine ball punch throws to be appropriate.


Evidence points to a greater potentiation effect in stronger athletes compared to weaker.

Athletes with a solid strength training background tend to experience greater improvements in the subsequent high velocity movement compared to weaker athletes.

This can be due to higher loads lifted by stronger athletes and thus greater motor unit activation along with a superior ability to recruit these high threshold motor units when lifting heavy loads.

Additionally, stronger athletes potentially have a greater ability to override neural inhibitory mechanisms, thus producing more force, higher rates of force development and higher power outputs, compared to their weaker counterparts.

Overall, stronger athletes tend to experience a greater fitness over fatigue ratio and thus are more likely to achieve a positive potentiation effect when compared to weaker individuals.


To attain a potentiation effect it is recommended that both the high force and high velocity be similar, biomechanically.

This means that joint angles, plane of movement and direction of force application of the two exercises in a complex set need to be considered.

Examples of complex pairs that can be effective include: Back Squat and Vertical Jump, Bench Press and Bench Press Throw/Medicine Ball Throw, Isometric Medicine Ball Punch Holds and Medicine Ball Punch Throws.

Additionally, the high-velocity movement should facilitate acceleration throughout the full range of motion. This means that ballistics such as jumping and throwing exercises are most appropriate as these eliminate any deceleration component.


Before discussing how we implement complex training with our boxers at Boxing Science lets think about how complex training can transfer to boxing, particularly the punching action.

As outlined previously, the potentiation effect gained from heavy lifts enhances neural drive for a brief period time and allows the athlete to express higher rates of force development during explosive actions such as jumping and throwing.

One of our main objectives at boxing science is to improve the rate of force development of the lower body as this is strongly associated with punch power.

Improving upper body rate of force development and explosiveness is also a key component of our programs as these qualities are essential to the deliver of fast, hard punches.

Exploiting the potentiation effect gained from complex training, we can improve our athletes’ ability to perform explosive plyometric activities and thus achieve strength and power adaptations that will transfer to improved punch power and ferocity.


The main thing to think about when implementing complex sets with boxers is the concept of fatigue versus potentiation.

Often fatigue can mask potentiation if the exercises selected and the loads prescribed are inappropriate.

Thus, at Boxing Science we tend to avoid complex sets with heavy lower body lifts such as the back squat and deadlift as these can overly fatigue the boxer due to high amounts of associated neural stress associated with these lifts.

Instead, when combining high load and high velocity lower body exercises we use contrast training with our boxers. Read more about contrast training for boxing here:

In some cases where equipment might be limited or when under time constraints, we may use isometric lower body exercises as the high force movement of a complex pairing, however, we don’t tend to do this often.

We usually implement upper body complex pairs to enhance upper body rate of force development and hand speed.

A common example is a heavy floor press or dumbbell bench press paired with a medicine ball throw.

The DB Press provides a cue, motivation and stimulus to really power through on the Med Ball Chest Pass, achieving high velocities and force outputs

We usually perform 3 reps of the DB Chest Press or floor press before performing 3-5 reps on the MB Chest Pass. This is usually repeated for 3-4 sets.

The loads may be anywhere between 65-80% 1RM for the heavy loaded exercise.

Bands may also be used during this type of complex pairing as they encourage acceleration throughout the movement which can transfer to hand speed and the force at the end range of the punch.

Such upper body complexes are fantastic during strength speed phases as they allow us to target both high force and high velocity ends of the force-velocity spectrum.

This can be extremely beneficial for maintaining strength levels developed in previous training phases whilst improving rate of force development with the introduction of more explosive movements.

Isometrics can also play a role in upper body complexes, particularly with punch specific movements as demonstrated above.

Between the exercises the rest is kept at a minimum, especially for upper-body exercises. 

In this case Super Featherweight World Champion, Terri Harper,  is performing an isometric hold which promotes maximal voluntary contraction and enhanced neural drive. 

These isometric punch holds also stimulate maximal tension through the core and lower body by encouraging full hip extension and therefore are an effective coaching cue for technique and maximal intent during the medicine ball punch throw. 

It also increases force production at the end range of punch and punch snap

The PAP response tends to be acute from isometric contractions and therefore Terri is straight into a high velocity movement in the form of medicine ball throws. 


Its important to emphasis full-body tension during the isometric hold particularly in the trunk and lower-body. 

These holds should be maintained for no more than 3-5 seconds as we don’t want the PAP response to be masked by fatigue, which would be the case if prolonged isometric contractions were performed. 

This is a great complex pairing during speed-strength or taper phases as soreness is minimised due to the absence of an eccentric contraction whilst being specific to the punching action.

3 secs by 3 Reps on iso holds, then 3 reps on MB punch throw. Return to iso hold on other side, and repeat for 3-4 sets. One series on each side equals one set.


As mentioned previously upper body complexes are useful during strength speed and speed strength phases.

Whilst there are considerable benefits of complex training for boxers it is important to treat this method as an advanced one and therefore boxers must be gradually progressed onto this strength training strategy.

This ultimately means that in the initial phases of their strength training, boxers should gradually build up towards maximal strength and improving an athletes maximal force production qualities in order to maximise the benefits of more advanced training strategies such as complex training.

Read more about gradually building up towards maximal strength training here:


Complex training is an effective training strategy for improving muscle strength and power.

This training strategy involves pairing a heavy loaded exercise with a light loaded exercise and thus exploits the post activation potentiation effect associated with high load, high force movements.

Some important considerations regarding the application of complex training include the loads used, the intracomplex set rest interval, the strength level of the athlete and exercise selection.

At Boxing Science, we primarily use complex training to develop upper body rate of force development due to the lower chance of fatigue masking potentiation with high load upper body movements.

Complex training is an advanced training method and therefore boxers should gradually progress to performing complex sets and should focus on developing maximal force capabilities in initial stages of their training.