Pavel Tsatsouline is the chairman of StrongFirst, Inc., of which a few of my colleagues in strength are a part of, and is a master of training methods involving the kettlebell. With his years of experience in physical and martial arts training, Pavel weighs in his thoughts on isometrics.
"Scientists dabbled with isometrics, or muscle contractions against
stationary objects, as far back as the 1920s. Then in 1953 German
scientists Hettinger and Maller shook the muscle world with their
study that concluded that you can add 5% to your strength a week by pushing or pulling against a stationary object once a day. Just once, only for six seconds, and at mere two thirds of a max effort!
Weightlifters and martial artists quickly jumped on the bandwagon. The former pushed and pulled empty bars against power rack pins; the latter tried to tear their black belts apart and pushed through walls with back fists.
Enter the Dragon.
But isos went out of fashion around the time of Bruce Lee's mysterious death, for reasons that had nothing to do with the effectiveness of this ingeniously simple method: the emergence of anabolic steroids--and the seep of flakiness and trendiness into the fitness world.
It is time to bring this secret weapon back.
Prof. Verkhoshansky (1977) lists the six advantages of isometrics,
slightly paraphrased below.
1. Accessibility of isometrics to everyone.
Although certain sport-specific applications of isometrics require
specialized equipment such as power racks, generally you can manage with such mundane items as a wall, rope, stick, doorway, or chair.
2. The ability to train any muscle at very precise angles.
A great benefit when you are trying to overcome a sticking point in a lift.
3. Great efficiency.
In the words of Prof. Yuri Verkhoshansky himself, "...a ten minute
session of isometric tensions in specially selected exercises will
replace a tiring one hour of weight training."
4. Insignificant muscle and bodyweight gains when compared to dynamic exercises.
This may or may not be an advantage from your
point of view. The extent of muscle hypertrophy depends on the
training protocol. Recent studies have registered respectable muscle growth from isometrics. For instance, Garfinkel & Cafarelli (1992) found a 14.6% increase in the cross-section of the knee extensors following eight weeks of isometric training. Increasing the duration of the contractions to a minute and longer, as explained below, is likely to yield even greater muscle gains--if you need them.
5. The ability to maintain high levels of speed-strength during
important competitions due to the fact that isometrics expend a lot
less time and energy than lifting weights.
6. Great for improving and fixing athletic technique.
Quoting Prof. Verkhoshansky, isometrics offer "A better opportunity to memorize the proper positions visually and kinesthetically than the dynamic mode. This makes the isometric method especially valuable for teaching and mistake correction."
I shall extrapolate on this subtle but extremely important point. Let
us use the military press as an example. In order to put up the
heaviest weight safely you need to ‘wedge’ yourself between the
barbell and the ground, every muscle tight. It is not an easy skill to
learn with a live weight but a piece of cake with isometrics. Stand
inside a doorway, on a stool if necessary, put your hands up against
the molding, and press. You will naturally tense up your legs and
waist. Remember that feeling when you press a barbell.
The 'wedge' is just as effective for quick moves. I use it to improve
my military and law enforcement clients' striking technique and power.
On my Martial Power: Hard Hitting Combat Secrets from the Russian Special Ops videos you can see an obvious improvement in a professional kickboxer's kicks and cage fighter's punches after just two days.
What are the disadvantages of isometrics?
Suren Bogdasarov (1991), the coach of Russian weightlifting legend
Yuri Vlasov, lists three drawbacks of isometrics. First, they are
counter-indicated for people with high blood pressure and heart
problems. Second, your muscles could lose their elasticity. The
solution is simple: massage your muscles and shake them to relax
between sets. Third, it is easy to lose your sense of exertion.
Bogdasarov recommends varying the intensity of isometric contractions to address this problem, for instance an easy set followed by an all-out set.
Prof. Alexey Medvedev (1986) urges caution in applying isometric
exercises to children and teenagers. He also warns that strength
development plateaus after six to eight weeks of isometric training.
This is not a problem as you are not supposed to train isometrically
full time anyway. Go iso for a month or two, then go back to your
regular strength training. Summer is the ideal time for an isometric only routine.
Scientists disagree on a lot of things but not on the frequency of
isometric training: daily training is ideal (Atha, 1981). It does not
mean that you cannot train less frequently; you just will not gain as
much. According to Hettinger (1961}, training every other day delivers only 80% of the strength gains of daily training and training once a week yields only 40%. "