changes in response to functional overload/resistance
training. For example, we previously found patellar ten-
don CSA to show very subtle changes after 15 wk (45 train-
ing sessions) of heavy resistance training [þ 1.4% (41)] and
no differences between long-term resistance-trained indi-
viduals and untrained controls (15).
Limitations
Although the current investigation provides a detailed
assessment of an individual at/toward the upper limit of
human strength performance, it is important to appreciate
study limitations. First, the participant was not measured im-
mediately before their World’sS t r o n g e s tM a nc h a m p i o n s h i p
success or other landmark performances, and it is entirely pos-
sible the functional and structural characteristics we assessed
m a yh a v eb e e ne v e nh i g h e rd i r e c t l yp r i o rt op e a kp e r f o r m a n -
ces. Despite using a wide-bore MRI scanner, due to the size of
the WSM’s shoulders and arms, it was not possible to scan their
u p p e rb o d y .T h u s ,w ew e r en o ta b l et oi n v e s t i g a t et h i sa s p e c to f
the WSM’s muscle morphology; although given that greater hy-
pertrophy occurs in the upper body compared with the lower
body (42), it is possible that the WSM’s upper-body muscle size
relative to untrained controls may have been even more pro-
nounced than what we have documented for the lower body.
In the current study to provide the most representative data on
untrained control participants, the largest available untrained
control populations were used for each category of measure-
ments. Thus, different untrained control populations were
used [e.g., comparison of quadricep and hamstring size (n ¼
102) vs. comparison of all the leg muscles (n ¼ 11)], which led to
some subtle discrepancies in the contrasts between these
groups and the WSM [e.g., quadriceps femoris/knee extensors,
þ 127% andþ 99% relative to our large pooled (n ¼ 102) and
smaller (n ¼ 11) untrained control samples, respectively].
Importantly, however, this discrepancy does not appear to
meaningfully affect the interpretation of theﬁndings. There
were subtle differences in the precise scanning and analysis
approaches used with the reference populations featured in
this study, including1)m a g n e t i cﬁeld strength [1.5 T (10, 11, 15)
vs. 3.0 T, WSM and (13, 14)]; 2) the interslice distance used to
quantify quadriceps femoris and hamstrings muscle volume
[1.5 cm (10, 11, 14)v s .2 . 0c m ,W S Ma n d(13)]; 3)t h ec a l c u l a t i o n
of muscle volume [area under the cubic spline ACSA-muscle
length curve: (10, 11, 14) vs. the equation detailed earlier: WSM
and (13)]; and4)t h eu s eo fu n i l a t e r a lM R Im e a s u r e sd e r i v e d
from one limb (10, 11, 14, 15) or collapsed across two limbs
[WSM and (13)]. However, it seems likely that these subtle dif-
ferences would have had at most a very minor effect on the
ﬁn d i n g s .F i n a l l y ,i ti sa l s oi m p o r t a n tt oh i g h l i g h tt h a tt h ed i f f e r -
ences documented between the WSM and comparative popula-
tions for the various measures included in the current study
cannot be assumed to be anything other than a combination of
both innate (genetic) and environmental (training and nutri-
tion) factors.
Conclusions
In conclusion, this novel investigation documented the
muscle and tendon morphology and whole body strength
and power characteristics of an exceptionally strong individ-
ual, relative to comparative athletic, trained, and untrained
populations. Overall leg muscle volume of the WSM was
approximately twice that of untrained controls but with pro-
nounced anatomical variability in the extent of muscular de-
velopment. The plantar ﬂexor muscle group and the guy
rope muscles (sartorius, gracilis, and semitendinosus:þ 140
to þ 202%), which stabilize the pelvis and femur, demon-
strated the largest differences. The pronounced quadriceps
femoris size of the WSM (greater than or equal to twice that