Although it was anticipated that the WSM would possess a
larger total lower-body muscle volume/mass than untrained
controls and other athletic/trained groups we have previ-
ously measured, the magnitude and pattern of the differen-
ces were unknown. The results indicated that the total
volume of the measured muscles was almost twice that of av-
erage untrained participants and 32– 63% larger than subelite
and elite sprinters. Pronounced development of the anti-
gravity muscles (i.e., hip extensors, knee extensors, and plan-
tar ﬂexors) was perhaps not that surprising given the WSM’s
background in heavy lifting events (including being a double
deadlift world champion and record holder). However, the
hipﬂexors appear less important in these tasks, possibly
explaining their more modest size, which was inferior to that
of three elite 100-m sprinters we have previously assessed.
The WSM’sp l a n t a rﬂexors were particularly large relative to
untrained controls (þ 120%). This could be due to the plan-
tar ﬂexors being the smallest of the antigravity muscle
groups that may experience very high mechanical stress
and, thus, a pronounced adaptive stimulus during heavy lift-
ing, carrying, and pulling tasks. Furthermore, the very heavy
and, therefore, low-velocity nature of these tasks may limit
the contribution of the stretch-shortening cycle and tendon
recoil to the positive/concentric work done by the plantar
ﬂexors, potentially placing a higher demand on the contract-
ile apparatus than for running and jumping tasks.
Considering individual muscles/compartments, the mus-
cular development of the WSM was distinctly nonuniform. It
is striking that the largest muscles relative to the untrained
control population were the three“guy ropes” (sartorius, gra-
cilis, and semitendinosus:þ 140– 202%). These three muscles
provide stability to the pelvis and femur by having origins at
diverse points around the pelvis while sharing a common
insertion onto the anteromedial tibia [via pes anserinus, the
conjoined tendons of these three muscles (39)]. Large guy
rope muscles likely enhance stabilization of the femur and
pelvis and would be expected to be critical during heavy
weight-bearing tasks. In contrast, the WSM’s ﬁve smallest
muscles (relative to untrained controls) consisted of two hip
ﬂexors (iliopsoas and RF) and two monoarticular kneeﬂexors;
actions that appear far less important for lifting, carrying, and
pulling tasks.
The WSM ’sq u a d r i c e p sv o l u m ea n dp a t e l l a rt e n d o n
moment arm were both greater than that of untrained con-
trols and indeed any individual we have previously measured.
However, the magnitude of difference, relative to the
untrained controls, was noticeably larger for quadriceps femo-
ris volume (greater than or equal to twice as large) than for
0 1000 2000 3000 4000 5000
Untrained control
Sub-elite sprint runners
Elite sprint runners
Long-term resistance-trained
WSM
A
QF volume (cm3)
0 100 200 300 400 500 600
E
RF volume (cm3)
0 200 400 600 800 1000 1200 1400
Untrained control
Sub-elite sprint runners
Elite sprint runners
Long-term resistance-trained
WSM
D
VI volume (cm3)
0 200 400 600 800 1000 1200
Untrained control
Sub-elite sprint runners
Elite sprint runners
Long-term resistance-trained
WSM
B
VM volume (cm3)
0 200 400 600 800 1000 1200 1400 1600
C
VL volume (cm3)
Figure 4. Quadriceps femoris (QF; A),
vastus medialis (VM; B), vastus lateralis
(VL; C), vastus intermedius (VI;D), and rec-
tus femoris (RF; E)m u s c l ev o l u m eo fa
World’s Strongest Man and deadlift cham-
pion (WSM) compared with long-term re-
sistance-trained (n ¼ 16, from the work by
Maden-Wilkinson et al. (10)], elite sprint
runners [n ¼ 5, from the work by Miller
et al. (13)], subelite sprint runners [n ¼ 26,
from the work by Miller et al. (13)], and
untrained control populations [n ¼ 102,
pooled population from the works by
Miller et al. (13)( n ¼ 11), Balshaw et al. (11)
(n ¼ 52), and Balshaw et al. (14)( p r e t e s t