No-Bullshit Leg Growth!

By Robbie Durand

People ask me all the time, “C’mon, this is not real… this has to be a Photoshopped picture of Jay Cutler’s legs, right?” You can look at the contest pics on musculardevelopment.com and see the exact same leg shot of Jay Cutler competing in Mr. Olympia— so there is nothing fake about Jay Cutler’s legs. Legs are a weak point for many people, and having weak legs can inhibit your progress in any bodybuilding show. So if you are not blessed with great legs, how the hell do you build them?

I have heard many anecdotal routines such as 100-rep squats, hitting legs every day, and doing high-volume sets, but it’s not often you can say that I have a routine that has withstood the scientific process and is proven to get your wheels bigger! Not only that, but the study was done in well-trained resistance athletes with at least five years of resistance training, which is just about every person who reads MD. One of the ‘flaws’ of some studies is that they use untrained subjects, which does not relate to MD readers. This study can be applied to every reader of MD who wants bigger legs.

If you go into any muscle physiology laboratory and ask the scientists how muscles grow, they will say muscle growth is an accumulation of many things— but a predominant factor is tension overload. Back in the early ’70s, researchers quickly realized that if you took a rat and had it walk downhill on a treadmill or induced tension overload by putting a muscle on stretch (eccentric contractions), all sorts of nasty things could be done to try and blunt muscle hypertrophy— but it did not stop muscle hypertrophy from occurring. Researchers removed the rats’ pituitary gland so they could not produce GH or IGF-1, castrated them so they could not produce testosterone, removed their thyroid, or just didn’t feed them. Despite this punishment, the rats still had increases in muscle hypertrophy in their legs.

In his research, Dr. Goldberg noted, “Maximal tension development leads to increases in muscle hypertrophy. Unlike normal developmental growth, work-induced hypertrophy can be induced in hypophysectomized [rats that can’t produce GH] or diabetic animals. This process thus appears independent of growth hormone and insulin as well as testosterone and thyroid hormones. Hypertrophy can also be induced in fasting animals, in which there is a generalized muscle wasting. Thus, muscular activity takes precedence over endocrine influences on muscle size.”10

So you can take all the drugs on the market, but if you don’t use high-tension overload, you will always be beaten onstage by someone who trains with this method. I have written about eccentric training principles in the past, but if this does not get you thinking about incorporating some eccentric training into your routine, then you must be satisfied with your leg growth. If you want to add a few inches to your legs, read on.

A Brief History of Eccentric Training

I write about the benefits of eccentric (ECC) training for muscle growth, yet at every gym I visit, rarely do I see bodybuilders controlling the negative portion— often it’s just the typical lowering in a second or less. A study published American Journal of Physiology – Endocrinology and Metabolism should encourage bodybuilders to emphasize maximal ECC contractions if they are looking to stimulate muscle hypertrophy.

Researchers were specifically interested in a protein called p70S6k. In recent years, marked progress has been made in identifying the signaling substrates essential for muscle growth and development. mTOR, which is stimulated by the amino acid leucine, is one— and another key signaling protein for muscle hypertrophy is p70S6k. Persistent overexpression of IGF-1 in skeletal muscle of mice results in hypertrophy, which is mediated via the mTOR/ p70S6k pathway.1

Another interesting fact is that muscle hypertrophy seems to be blunted in aged humans, and one of the reasons may be that mTOR and p70S6k are increased in skeletal muscle after a single bout of intense contractile activity in aged animals— but the response is less than that observed in younger animals.2 These observations suggest that the anabolic response of both mTOR and p70S6k to a single bout of contraction is attenuated by aging, and may help explain the reduced capacity for hypertrophy in aged humans.

It has been well documented that ECC contractions are more important for muscle hypertrophy than concentric (CON) contractions, but the anabolic signaling proteins have not yet been investigated. Researchers from Sweden had 10 male subjects perform either 4 sets of 6 reps of maximal eccentric contractions on one leg, followed by 4 sets of 6 reps of maximal concentric contractions on the other leg. The subjects were trained in a fasted state. Researchers took muscle biopsy samples from the subjects’ upper thighs in both legs before, immediately after, one hour and two hours after exercise. The results indicate that one session of maximal ECC contractions activates the hypertrophy-signaling protein p70S6k (more on this important protein later) in human muscle, and suggest that maximal ECC contractions are more effective than maximal CON contractions in stimulating protein synthesis in the absence of nutritional intake.2

Interestingly, maximal CON contractions did not increase activity of p70S6k, which may be the reason many researchers have reported that performing CON contractions without an ECC contraction does not yield increases in muscle mass.

p70S6k Correlates With Increased Muscle Mass

The anabolic benefits of resistance exercise are likely to be mediated through changes in signal transduction proteins. One of the key anabolic-regulating proteins is p70S6k. This protein has emerged as an important factor in muscle cell size regulation, as it is a regulator of the mTOR pathway— known to regulate muscle growth.

p70S6k is an important activator of insulin/IGF-1 pathway.3 Animal studies have reported that castration and a subsequent decline in testosterone leads to a rapid decrease in p70S6k and muscle atrophy. However, administration of testosterone induces a rapid increase in p70S6k and upregulation of IGF-1.4 Interestingly, the muscle hypertrophy induced by clenbuterol was associated with local increases in IGF-1 and p70S6k in muscle.5,6

p70S6k increases key signaling proteins that stimulate muscle protein synthesis— insulin,7 growth factors, hypertrophic agents8 and branched-chain amino acids all increase p70S6k activity in muscle. Exercise-induced increases in p70S6k activity correlate with increased muscle mass after six weeks of resistance exercise and with elevated protein synthesis rates in muscle, both 12 and 24 hours into recovery. Based on the research, an increase in p70S6k activity increases protein synthesis and correlates with increased muscle mass.

Operation Leg Growth!

Researchers from Germany took 30 well-trained athletes with at least five years of training and divided them into two groups. The first group did standard weight-training exercises with standardized leg extensions, which were performed for six weeks. The other group performed the exact same routine, but when they lifted the weight up on the leg extension machine, they increased the weight during the eccentric portion— which caused an eccentric overload for the bottom portion. Both groups performed 5 sets of leg extensions with an 8-rep maximum.

Here is the interesting twist that many bodybuilders are probably not used to— the subjects trained legs three times a week (Monday, Wednesday and Friday). The athletes were told to perform each movement as explosively as possible, but with good form. The subjects trained to absolute failure with each set. They used a workload for the eccentric portion that was nearly double that of the concentric portion, so if they lifted with 100 pounds, they lowered the weight with nearly 200 pounds. They trained like this for six weeks, had muscle biopsies done and had their tissues analyzed for muscle growth factors. At the end of the six weeks, the athletes were measured for strength and muscle hypertrophy.

Both groups had increases in muscle mass and strength, but the traditional weight training with the eccentric overload group kicked the traditional weight training group’s ass! Eccentric overload resulted in greater increases in fast-twitch muscle fibers, greater increases in the androgen receptor, greater increases in genes regulating muscle hypertrophy, enhanced satellite cell activation, and greater muscle strength.10 The group that performed the eccentric overload had a greater overall anabolic response, compared to conventional training— basically resulting in a bigger, stronger, and faster athlete.

So my question to you is— why the hell aren’t you incorporating some eccentric movements in your training routine? Try this, next time you go to the gym to train legs: at the end of your leg session when you do leg extensions, have a training partner push down on the eccentric portion and as you get to the bottom, have your partner let go. You are going to have to use a much lighter weight than normal, but you are going to feel it during the next few days. This technique can be used for any lagging body part.

I’ve given you a practical application for using eccentrics. The plan is going to make you sore as hell, but the benefits are well worth it. The study used an apparatus that overloaded the eccentric portion on the way down, but you can have a training partner push down as hard as possible while you are doing leg extensions, which will mimic the device. If you don’t have a training partner, do the concentric portion with two legs and lower with one leg. Either method will produce eccentric overload and result in a similar effect. This type of training does not only apply to legs, but could also be used with other muscle groups as well.

source:www.musculardevelopment.com