The reasons to stop doing
sit-ups keep piling up. First, Stuart McGill, professor of spine biomechanics at
, declared the sit-up more harmful than helpful. And now a study out of
says sit-ups don’t build strong abs.
The goal of the study
was to find the most effective method to strengthen the rectus abdominus, the
long flat muscle that runs from the sternum to the pubic bone and forms the much
coveted “six-pack.” Despite the fact that we have been doing sit-ups for
years, there is a lack of definitive research stating the optimum training
protocol necessary to maximize strength gains.
Some experts suggest
that the abs, like any other muscle, benefit from an every-other-day training
routine. Others maintain that a daily diet of sit-ups yields the best results.
And then there is the question as to whether a traditional sit-up done without
any added resistance (beyond body weight) provides the necessary training
stimulus to strengthen the abs.
study, published in the October 2009 edition of the “Journal of Strength and
Conditioning Research,” separated 71 men and women into three groups. The
control group did no sit-ups. The other two groups performed three sets of 20
repetitions (30 seconds rest between sets) of three distinct abs exercises for
11 weeks. Group One performed the sit-ups three times a week on non-consecutive
days and Group 2 trained the abs six days per week. The ab exercises increased
in difficulty every four weeks and speed was regulated by a metronome.
The results surprised
even the researchers. None of the three groups of exercisers demonstrated any
strength gains. Nor did they reduce their waist circumference or percentage of
suggests that training the abdominals with resistance levels short of fatigue is
inadequate to produce strength gains and may be consistent with findings
suggesting that pushing a muscle to repetition failure is more effective in
producing strength gains,” said the study authors, Jennifer Pinter, Ken
Learman and Renee Rogers.
The authors did
acknowledge that the exercise regime may have improved muscular endurance, but
it was not measured in the study.
What does that mean
for anyone who wants a stronger set of abs? The message is clear - sit-ups
aren’t going to get the job done. Muscles need to be sufficiently fatigued
before they can build strength. That fatigue is notable only when the muscle has
reached its repetition limit - at which point your abs are so fatigued that you
can’t perform even one more sit-up.
That being said, when
it comes to well conditioned abs, strength may not be your ultimate goal. McGill
suggests that building muscular endurance is more important than building
muscular strength -- at least initially. Which means training the abs to work
harder longer is better than developing strength without endurance. He also says
that repeated bending of the spine (similar to the action that occurs during a
sit up) increases the risk of back pain.
“Realize that the
spinal disks can bend only so often before damage ensues,” McGill said in a
January 2010 article titled The Painful Lumbar Spine, published in the “IDEA
Then there is the
issue of function. The primary role of the core muscles is to stabilize the
torso, not perform the type of torso bending action found in a sit-up.
So, if curl ups
don’t strengthen the abs, don’t train the core for everyday use and do more
to provoke back pain than diminish it, why do them? McGill preaches improving
stability, not mobility, and training all the muscles that surround the trunk,
not just those that build a six pack. He also recommends a revamped curl-up that
saves the spine while contributing to a core that is better able to withstand
the demands of everyday life.
If you want a
better-conditioned set of abs, substitute curl-ups for stability exercises like
the plank or consider trying McGill’s modified curl-up (see below). Time in
the gym is too precious to waste it on exercises that fail to live up to their
modified curl-up: Lie on your back with one leg straight and the other bent.
Place both hands under the small of the back. Lift the shoulder blades off the
floor (don’t curl the spine), hold for a couple of seconds and return to the