Tag Archives: weightlifting

Packing a punch: Does strength indicate boxing performance?

Every sport has a different “ideal” body type, which is largely dictated by the muscle groups it focuses on training. Swimmers prioritize developing the muscles in their shoulders and backs, which allows them to propel themselves through the water with their arms. On the other hand, runners prioritize the hamstrings and quads in their legs, which allows them to generate greater force when pushing off of the ground. So, what is the ideal body type for boxing? Strength is clearly important when punching an opponent, but is it even the most important factor in boxing performance? Should either upper- or lower-body strength be prioritized over the other?

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Photo by Bradley Popkin for Men’s Journal.

The overall goal in boxing is to either knock out your opponent with a single punch or land more punches in the scoring area than your opponent. One of the best ways to achieve the latter is by wearing down your opponent with powerful strikes to reduce their ability to retaliate. Therefore, hitting your opponent, and hitting them hard, is crucial within the sport of boxing. 

First, let’s take a look at upper-body strength. Boxers execute punches by using muscular force to accelerate their arms, so it is easy to assume that arm strength is the most important factor in punch performance. However, this may not be the case. One of the most common upper-body strength exercises is the bench press, and research has shown that there is no significant correlation between the maximum weight a boxer can bench press and the force they deliver in a punch. While this may be surprising, the relationship between upper-body strength and punching actually comes down to speed rather than force. Based on data from both professional and elite amateur boxers, the maximum speed at which a boxer can bench press is indicative of improved punch performance. More specifically, professional boxers showed a strong relationship between the maximum velocity of their bench press and maximum punch velocity of their rear, or dominant, arm. 

If upper-body strength does not indicate punch force, then does lower-body strength? A study of amateur boxers found a positive correlation between maximum punch force and lower-body strength measures, including countermovement jump (see video below) and isometric midthigh pull. In contrast to the upper-body exercises, the maximum force generated in lower-body exercises is more important for increasing maximum punch force than the speed at which the exercise is completed.

Plot of countermovement jump force in Newtons versus punch force in Newtons. The data has a correlation of 0.683 and a p-value of less than 0.001. Plot of isometric midthigh pull force in Newtons versus punch force in Newtons. The data has a correlation of 0.680 and a p-value of less than 0.001.
Plots showing a strong, positive correlation between punch force and the lower-body strength exercises, countermovement jump, CMJ, (left) and isometric midthigh pull, IMTP, (right). Adapted from “Relationships Between Punch Impact Force and Upper- and Lower-Body Muscular Strength and Power in Highly Trained Amateur Boxers” by Emily C. Dunn, et al.
Video of how to execute the countermovement jump test by Training & Testing.
Kinetic Chain: Force is generated from the floor and transferred from foot to fist. Leg force, hip and torso rotation are key. Arrows show movement of force from foot, through the body, to fist.
Graphic of Kinetic Chain in a boxer from Boxing News.

When executing a punch, a boxer gains forward momentum by pushing off of the ground with their legs. Through a kinetic chain, force moves through a boxer’s body from the floor to the foot, then through the legs and torso, and finally, to the arm and hand. This phenomenon is what explains why lower-body force is crucial to a boxer’s maximum punch force. 

So, what does this all mean? How should boxers train in order to improve their punching performance? Most importantly, boxers should focus on their lower-body strength, as it is the most direct indicator of maximum punch force. While lower-body strength should be a primary training goal, exercising muscles within the upper-body, specifically while focusing on the speed of the movements, will also likely improve overall punch performance. We now know that developing strength is clearly beneficial in improving a boxer’s punch; however, brute force alone does not win a fight. Boxers should develop correct boxing technique through methods such as those suggested in this article, which will allow them to implement their new strength in the most effective manner.    

For additional information on the impact of strength on athletic performance click here and here.

The Benchmark of Upper Body Strength: Injury Prevention During the Bench Press

Who wouldn’t want to look like Captain America? This common desire to attain a strong Herculean physique, either for athletics or aesthetics, has led many ambitious men and women to weightlifting. An egotistical motivation puts these people at risk of injury, however, as they sacrifice proper form to achieve their next personal best. The bench press is one example of an effective but potentially dangerous lift.

This upper body exercise requires an individual to lie flat on a bench while repeatedly lowering and pressing a straight bar loaded with weights on each end. The hands evenly grip the bar slightly wider than shoulder width apart with the feet remaining flat on the ground and the arms fully extended. During the eccentric (or lowering) phase, the bar is brought in contact with the lower chest. The bar is then pressed up until the arms are once again fully extended (concentric phase).

Recreational weightlifters commonly use a wider grip on the bar, believing that this will increase activation of the chest muscles and allow them to mimic Terry Crew’s version of the Old Spice Man. One study performed on 12 powerlifters, however, found that the prominent muscles used during the lift, such as the pectoralis major, triceps brachii, and anterior deltoids (i.e. chest, triceps, and shoulders), experienced similar electromyographic activity despite varying hand spacing.

Diagram of a human upper body muscular system.
Image by OpenStax from Wikimedia Commons.

Although hand spacing does not significantly affect muscular activity, it can lead to injury. A review of several studies on the effects of hand grip found that a grip width greater than 1.5 times biacromial width, or shoulder width, naturally resulted in shoulder abduction, or rotation away from the body’s centerline, greater than 45°. As this angle increases, shoulder torque increases, causing potential injuries. For instance, the inferior glenohumeral ligament, a ligament restricting translational motion in the anterior direction at the shoulder’s ball and socket joint, may tear as abduction increases, causing instability at that joint. Repetitive cycles with this wider grip may also cause acromioclavicular joint (AC Joint) osteolysis – chronic destruction of the bone tissue at the joint between the clavicle and acromion.

Diagram of shoulder joint.
Image by OpenStax College – Anatomy & Physiology from Wikimedia Commons.

Aside from a wide grip, injuries also commonly stem from over-training and using excessive weight. Research on 18 male college students demonstrated that repeating the bench press motion with high frequency until failure resulted in a significant increase in the medial and lateral force exerted on the elbow joint, which could result in injury over time. Furthermore, performing the bench press with heavier loads could result in a sudden rupture of the pectoralis major. At the bottom of the eccentric phase as the bar touches the chest, the muscle fibers are simultaneously lengthening while also contracting, which increases the risk of muscle tear in this region.

Unlike Captain America, people cannot instantly acquire strength or build muscle. Muscular development and improving one’s bench press require time, patience, and proper form. To learn more about injury prevention or variations of the bench press, check out the video below or read these papers by Bruce Algra and JM Muyor.

Sources can be found below:

The Affect of Grip Width on Bench Press Performance and Risk of Injury

The Effects of Bench Press Variations in Competitive Athletes on Muscle Activity and Performance

Elbow Joint Fatigue and Bench-Press Training

An In-Depth Analysis of the Bench Press

 

Look Strong, Be Strong, or Be Safe?: The Perils of a New Deadlifter

So, you’ve started deadlifting, but you’re not sure if you’re just weak, or if you’re going to break your spine, and there are plenty of “gym bros” slamming the weights, grunting, and walking around wearing equipment (wrist straps and back belts) that says “I’m literally too strong for my own body.” So, what do you do? Do you need to buy that stuff too?

This blog post will walk you through a biomechanical analysis of the deadlift while wearing supportive equipment, in the hopes of helping you face this daunting task.

First, let’s look at the proper form and muscles recruited in the Deadlift.  As can be seen in the graphic below, the lift begins on the ground in a hinged squat. From A to C, The gluteus maximus (butt), trapezius and lower erector spinae (long muscles that run alongside the spine) are primarily activated, whereas from C to D, the hip extensors and numerous smaller upper back muscles help to “lock out” the form, with the forearms supporting the load throughout.

Graphic of a side view of the proper deadlifting motion
Graphic Depicting Proper Form

The science of using wrist straps as discussed here.  Your forearms are significantly weaker than your gluteus and back, and as such, they will fail first. A comparison of different kinematic variables as a function of wrist straps and unsupported showed a higher activation in the back when using straps.  This means, when using wrist straps, you reduce the load on your forearms, which allows you to go heavier with weight.  In essence, it takes grip strength out of the lift.

Improper form, like arching your back, hips rising too early, leaning too far forward, or many other small inefficiencies can lead to concentrated shear stresses between the vertebrate in the back (not good), excessive reliance on small ligaments in lower back (not good), and high stress concentrations at the moment hinge (especially not good considering your lower back is a nerve junction between your sciatic and spinal nerves).  So how do you prevent this?

Many people instantly reach out to supportive equipment as their saving grace, but does this really prevent injury or does it just add a false sense of security to allow dangerous form? Studies by Thomas and Kingma both look at the effectiveness of weightlifting belts in protecting your spine in various loading conditions.  Although I encourage you to read them and discover their findings for yourself, they both reach generally the same conclusion.  Belts might help, by increasing Internal Abdominal Pressure (IAP) says Thomas, and by decreasing spinal load, tested by Kingma, however, any benefit is nominal.

As far as my suggestion goes, you should begin deadlifting at lower weights, without a belt or straps, until you get a feel for the form.  This will begin to increase your strength in the smaller muscles and form muscle memory required for heavier lifting.  Listen to your body. If a lift went well, and you think you can increase the wight without sacrificing form then go up in weight. Eventually, a weightlifting confidence will step in, and you’ll be able to determine for yourself which strength you want to strive for (grip strength, or bigger deadlift numbers).

If profane language is no issue for you, I STRONGLY encourage watching the YouTube video appended below. Eddie Hall, a now retired professional strongman, owns the record for the ONLY 500 kg Deadlift, and he most certainly knows what he’s talking about.

PS he trains without any supportive equipment, and safe to say he’s lifting heavier than you.

Continue reading Look Strong, Be Strong, or Be Safe?: The Perils of a New Deadlifter

Muscle Loss Due to Aging

It is a well-known fact that as we get old, our bodies (sadly) deteriorate, leaving us unable to perform certain physical functions as easily as we could have when we were younger. In this article, the authors describe a study done to analyze muscle loss due to aging, primarily by examining two different age groups of humans. By conducting measurements on people over and under the age of 40 years, results show a clear difference in muscle mass and strength between the two.

Karsten Keller and Martin Engelhardt conducted their study on 14 adults under the age of 40 and 12 adults over the age of 40. They measured the circumference (size) of each leg of the participants in four different locations at 10 and 20 cm above the knee, and 10cm below it along with the largest circumference position below the knee. In addition, they conducted strength tests based on the motion of the leg at 30˚ and 60˚ from resting sitting position using the Dynamometer BIODEX® System 3.

Man Lifting Weights
Photo by Sopan Shewale on Unsplash

Results given in the article can be viewed in full here, but as a summary both the overall size and strength of legs was stronger in the younger participant group than in the older group. According to the authors, we as human beings generally are at our physical peak throughout the 20-30 year age range. From analyzing their own experimental results, Keller and Engelhardt conclude that our muscle mass generally begins to decline after about 40 years of age. The factors that contribute to the size and strength of our muscles declining due to aging is varied and complex, but one reason for our weakening is that as we age our muscle fibers decline in number. Once enough fibers are lost, our bodies experience apoptosis, or the destruction of cells. Anabolic hormone decrease, risk of disease, appetite loss, and declining of physical activity are all other large factors attributed to muscle loss in aging.

Maximum isometric strength of the left leg in 60° flexion of both groups.
Maximum isometric strength of the left leg in 60° flexion of both groups.

Maximum isometric strength of the right leg in 60° flexion of both groups.
Maximum isometric strength of the right leg in 60° flexion of both groups.

Human beings get old, and physically, it is not that great. Our muscle strength and size decline due to a number of factors. However, we can help ourselves fight physical aging by paying attention to our health, specifically maintaining some physical strength training and ensuring we receive nutrients to feed our muscles. The authors recognize the limitations of this study, including small sample size and desiring ages from every decade; however they are able to conclude by stating that their data shows that muscle declines after 40 years of age in a range from 16.6% – 40.9%. To learn more about some causes of muscle loss through aging, such as sarcopenia, inactivity, and physiological changes check out these articles.

 

Gainz for Dayz: Conventional vs Sumo Deadlift

What’s the best way to pick stuff up and put it back down?

A large tattooed man deadlifting enough weight to bend the bar in the conventional form.
Photo by Alora Griffiths on Unsplash

By deadlifting, of course.  The deadlift is, arguably, one of the most important exercises a weight lifter can perform.  Although primarily thought of as a lower body exercise, the deadlift activates muscles throughout the entire body, and is one of the three all-important lifts for any lifting routine.  Although there are a variety of different deadlift form variations, two of the most prevalent are the conventional deadlift and the sumo deadlift.  The main difference between these two stiles is that in the conventional deadlift, the hands are placed on the outside of the knees, while sumo deadlifting places the knees outside of the hand.  The everlasting debate is therefore which form is the better one?

In attempt to answer this, tracking data was used to employ a biomechanical analysis of these two forms of deadlifting. One of the biggest differences they found was in the distance that the bar had to travel from the beginning of the lift to the completion of the lift.  In the sumo deadlift, the significantly wider foot stance results in a 19% decrease in the distance the bar must travel, decreasing the amount of work that the lifter needs to use.  It therefore seems that the conventional deadlift, if it requires more work, is the better form, right?  Well, maybe.  The researchers also found that the sumo deadlift conveyed a biomechanical advantages compared to the conventional deadlift.  This was mostly due to a more upright trunk at the beginning of the lift, resulting in less trunk extension being required to complete the lift, although it consequently may require more flexibility to perform.  This in turn decreases the moments of the bottom two vertebrae and shear forces on them, and the sumo deadlift therefore seems to have a safety advantage over the conventional deadlift.

The postures of athletes performing the conventional and sumo deadlifts as determined by tracking body points through video footage.
Modified from McGuigan and Wilson, Journal of Strength and Conditioning Research 1996

But what about muscles?  What should you do if you want to gain strength by pushing your muscles to work harder?  As the study showed, the conventional deadlift needs an increased amount of energy to complete, but are all the muscles used in the two forms the same?  Researchers at Duke University Medical Center decided to use electromyography (EMG) to find out.  They found that the wider stance assumed in the sumo deadlift, besides conveying the safety advantages mentioned above, also resulted in an increased recruitment of some of the lower body muscles.  Namely, the vastus lateralis, the vastus medialis, and the tibialis anterior, or the outer (and strongest) and inner thigh muscles as well as the shin muscle.  The conventional deadlift recruited only the medial gastrocnemius (inner calf) significantly more than the sumo deadlift.  The recruitment of the vastus lateralis and vastus medialis make sense, since having your feet placed more directly under you in conventional deadlift would tend to recruit the more central thigh muscles.

With all of the above, it looks like sumo be the better option: it decreases stress on the back, recruits more lower body muscles, and indirectly places a focus on flexibility.  However, if you’re not convinced, Men’s Journal, BarBend, and Starting Strength provide some additional commentary comparing these two methods.

For the following video provides a better explanation of the differences in form between the two styles of deadlift.