BLUF (Bottom Line Up Front)
This study examines the relationship between maximal and explosive strength and punch impact force in elite amateur and professional boxers. The findings indicate that lower-body strength and explosive power strongly correlate with greater punch impact force, while upper-body maximal strength has little impact.
However, a major limitation of the study is the lack of explicit statistical control for body weight. Larger boxers naturally produce higher punch forces compared to smaller boxers of similar skill level, which may have inflated the observed relationship between strength and impact force. The study does incorporate relative strength measures (force normalized to body mass), and when this adjustment is made, the connection between strength and punching power weakens significantly. These findings suggest that strength is important for punching power, but its role must be understood in the context of body weight and weight classes.
Key Discussion Points
1. Purpose of the Study
The study aimed to investigate how maximal and explosive strength in both the lower and upper body contributes to punch impact force in boxers. The key research questions were:
- Does maximal strength improve punch force?
- How does explosive strength compare to maximal strength in predicting punch power?
- Does upper-body or lower-body strength play a more significant role in generating a powerful punch?
- Are boxers with greater punch impact force stronger than those with lower punch impact force?
While prior research has explored biomechanical factors affecting punching performance, this study focused on strength development and its role in generating impact force.
2. Strength and Punch Impact Force – Findings With a Caveat
The study analyzed multiple strength metrics and their relationship to punch force. The key findings included:
- Lower-body maximal strength correlates strongly with punch impact force.
- Boxers with higher peak force in the isometric mid-thigh pull (IMTP) produced significantly greater punch impact forces.
- Lower-body strength was a better predictor of punch power than upper-body strength.
- However, when body weight was considered, the relationship weakened.
- Explosive strength in both the upper and lower body may correlate with higher punch force.
- Countermovement jump (CMJ) peak power was linked to better punching performance.
- Explosive upper-body movements (e.g., bench throws) correlated with punch speed, but not impact force.
- Upper-body maximal strength does not contribute significantly to punch force.
- Isometric bench press (IBP) peak force did not correlate with punch impact force.
- When relative measures were used (adjusting for bodyweight), upper-body strength became a better predictor, suggesting pound-for-pound upper-body strength is important, rather than absolute strength.
3. Does Bodyweight Explain the Relationship Between Strength and Punching Power?
One of the major issues in interpreting the results is that the study does not explicitly adjust for body weight in statistical models. Instead, it relies on relative strength measures (force normalized to body mass) to evaluate how weight influences punch power. The key findings regarding body weight include:
- Absolute lower-body strength (IMTP peak force) correlates with punch force, but relative lower-body strength (force per kg of body weight) does not.
- This suggests that heavier boxers punch harder primarily because they are heavier, not necessarily because they are stronger for their size.
- Upper-body strength was not linked to punch force in absolute terms, but relative upper-body strength (bench press force per kg) correlated with punch force.
- This suggests that for upper-body strength, relative strength is more important than absolute strength in generating forceful punches.
- Boxers in the “high punch force” group were significantly heavier than those in the “low punch force” group.
- The difference in body mass largely explained differences in punch force, meaning strength alone is not enough—size also plays a role.
These findings highlight the importance of accounting for weight class in boxing performance research. Strength training should focus on maximizing relative strength (force per kg) rather than just absolute strength to ensure power improvements without excessive weight gain.
4. Comparison of Strength Metrics Between High- and Low-Impact Punchers
The study categorized elite amateur boxers into low-, medium-, and high-impact punchers based on recorded punch forces and compared their strength metrics.
| Strength Quality | Assessment | Low Punch Force | Medium Punch Force | High Punch Force |
|---|---|---|---|---|
| Lower Body Maximal Strength | Isometric Mid-Thigh Pull (Peak Force) | 2048 N | 2275 N | 2626 N |
| Lower Body Explosive Strength | Countermovement Jump (Peak Power) | 3142 W | 3804 W | 4087 W |
| Upper Body Maximal Strength | Isometric Bench Press (Peak Force) | 677 N | 879 N | 679 N |
| Upper Body Explosive Strength | Bench Press Throw (Power) | 388 W | 464 W | 479 W |
Interpretation of These Results:
- Higher punch force boxers had significantly greater lower-body strength and power, but they were also heavier on average.
- Upper-body maximal strength did not correlate well with punch force, but upper-body explosive power did.
- Once bodyweight was considered, lower-body strength differences between high- and low-punch groups diminished.
- Punch force correlation was only observed with the cross (dominant hand, straight punch), not in jabs, hooks, or uppercuts.
This confirms that absolute lower-body strength contributes to punch force, but its effect is heavily influenced by bodyweight.
5. Study Limitations and Future Research Needs
While the study provides important insights, it has methodological shortcomings that limit its conclusions:
- No direct statistical adjustment for bodyweight in regression models.
- The study presents absolute and relative strength measures but does not formally test whether bodyweight independently predicts punch force.
- Lack of weight class analysis.
- Comparing boxers within weight classes would help clarify if strength itself predicts punch power, independent of size.
- More focus needed on strength-to-weight ratio.
- The best measure for boxing performance is relative strength—force per kg of body mass. Future studies should emphasize this more.
Future research should use analysis that includes strength, body weight, and weight class as independent variables to isolate the true impact of strength on punching power.
Author’s Notes
I have been around boxing for 17 years as a amateur competitor, hobbyist, and fan of the sport. This study isolates a trait of boxing (max single punch power) that is arguably the least important component of the sport. Some are gifted by the gods with one-punch knock-out power such as Deontay Wilder, David Tua, and George Foreman… all heavyweights of wildly different builds.
The most successful boxers are capable of throwing punches in bunches with extreme accuracy and perfect footwork (Floyd Mayweather, Vasiliy Lomachenko, Roy Jones Jr, Muhammed Ali… multiple weight classes) and as a means to set up the appropriate offset angles for landing hard, well-placed strikes.
If implementing strength and conditioning in support of boxing competitively, a more thorough needs analysis should be conducted of the demands of the sport before recommending protocols.
Conclusion
This study offers important but incomplete insights into the relationship between strength and punch impact force. It confirms that lower-body strength and explosive power are critical for generating high-impact punches, but it fails to fully adjust for body weight in statistical models.
The findings suggest that bigger fighters punch harder, and their superior absolute strength plays a role, but pound-for-pound strength is more important than raw strength alone. As it relates to one-punch maximal power development, training should prioritize developing explosive strength without excessive weight gain, focusing on maximizing power relative to body size.
Until further research controls for body weight in statistical models, the role of strength in punching power remains closely linked to body mass, meaning fighters must strike the right balance between increasing strength and maintaining agility within their weight class.
Bibliography
- Beattie, K., & Ruddock, A. (2022). The role of strength on punch impact force in boxing. Journal of Strength and Conditioning Research.