I did an experiment based on some new data I discovered about tendons. My 8-year knee tendinitis is gone as of 2014. It had to do with exercising more frequently. I got a lot stronger in just 3 weeks. After 6 weeks, I hit my then all-time squat max of 365 for an easy single rep.
In my own life experience, perhaps the safest and least time-consuming way to pursue total body fitness is to train with somewhere between 6 and 12 exercises and train with perfect form, taking each exercise to a state of complete positive muscular failure, briefly resting and then moving to the next exercise. Your muscles are getting an intense workout, your hardest reps happen when the muscles are producing the least force (because they are tired) and none of the movements are “explosive” thus accelerating the weight to very high velocities and risking injury. During workouts of this nature, your heart feels like it might explode out of your chest, you breath very hard, and your veins pump lava or pieces of broken glass. The problem with training this way, at least for me, is psychological. Every workout must be all out if you wish to make steady progress. Other problems are related to trying to plan for enough rest and when you train this way the metabolic demands are high. Research shows that muscle protein adaptations last for up to 21 days after the most recent bout of training. Energy system adaptations can begin to regress within 4-7 days. I wish I could remember where I found that data, but I remember everything but the name of the study and it’s authors…which means nothing. Nevertheless, training like every workout is a zero-sum game can be psychologically defeating. Also, the training is seldom enough that other types of adaptations apparently cannot happen (more on that later, as it is the point of the article).
Personal Story: Knee and Back Pain
When I was 20 I woke up one morning with very bad knee pain. This came right around the same time I seriously injured my back. I went to a doctor and received an x-ray on both offending pieces of my body. The knee pain was determined to be very serious tendinitis (probably from a knee collision in a jiujitsu match a while before). The back injury, which was missed in the x-ray but was confirmed by another doctor, was a torn ligament between a rib and one of my vertebrae (don’t remember which). Anyhow, I was told to lay off exercise for 6 weeks. If my knee still hurt, it was recommended that I start walking more than just at work and home to facilitate recovery for 6 more weeks. It was especially important that I do no squats or dead lift. If it still hurt, I was told to go back (maybe to get recommended for physical therapy). A weird series of events involving a car accident occurred which lead me to hit the weights again despite the pain about 3 months later. I was weak, fatter than I’d ever been, and my first set of squats did two things: left me gasping for breath and trying my hardest not to puke and when the muscle soreness my knee and back hurt less. TMy knee never stopped hurting, it just hurt less.
Research on Tendon Adaptation
Anyhow, fast forward to now and I started using Ebsco to do research through the public library (out of grad school so I don’t get my own key code anymore). I discovered that there have been several advancements in the knowledge of connective tissue adaptation since my time as an exercise science major. For instance, in 2007 a study was published (though with no control group) observing the effects of leg extension training on subjects doing heavyweight with one leg and light-weight with the other. There were several interesting observations, but what was most pleasing to discover was that the patellar tendon actually experienced hypertrophy as well as increased stiffness (a good thing for joint health) in the leg trained with heavier weight:
In summary, the present study is to the best of our knowledge the first human study to report tendon hypertrophy following heavy resistance training. Further, the data show that tendon hypertrophy to heavy-resistance training in the patellar tendon was related to the proximal and distal region, but not to the mid-region of the tendon.Kongsgaard, M., S. Reitelseder, T. G. Pedersen, L. Holm, P. Aagaard, M. Kjaer, and S. P. Magnusson. 2007. “Region Specific Patellar Tendon Hypertrophy in Humans Following Resistance Training.” Acta Physiologica 191 (2): 111–21. doi:10.1111/j.1748-1716.2007.01714.x.
In the abstract of a literature review from 2006, I found that
For tendons, metabolic activity (e.g.detected by positron emission tomography scanning), circulatory responses (e.g. as measured by near-infrared spectroscopy and dye dilution) and collagen turnover are markedly increased after exercise. Tendon blood flow is regulated by cyclooxygenase-2 (COX-2)-mediated pathways, and glucose uptake is regulated by specific pathways in tendons that differ from those in skeletal muscle. Chronic loading in the form of physical training leads both to increased collagen turnover as well as to some degree of net collagen synthesis. These changes modify the mechanical properties and the viscoelastic characteristics of the tissue, decrease its stress-susceptibility and probably make it more load-resistant.Kjær, Michael, Peter Magnusson, Michael Krogsgaard, Jens Boysen Møller, Jens Olesen, Katja Heinemeier, Mette Hansen, et al. 2006. “Extracellular Matrix Adaptation of Tendon and Skeletal Muscle to Exercise.” Journal of Anatomy 208 (4): 445–50. doi:10.1111/j.1469-7580.2006.00549.x
Several other studies report the same sort of results. The most interesting things to me are A) The increase in protein synthesis B) The increase in blood flow (which can provide nutrients for recovery) C) That actual hypertrophy can be stimulated in tendons D) that even body weight squats increase tendon stiffness in elderly and untrained populations. But what was most interesting to me on a personal level was that “collagen synthesis in human tendon rises by around 100% with just one bout (60 min) of acute exercise, and the elevated collagen synthesis is still present 3 days after exercise (Fig. 3; Miller et al. 2005). In skeletal muscle, the rate of collagen synthesis also increases with exercise, in a time-dependent manner that follows the increase in myofibrillar protein synthesis with exercise (Miller et al. 2005).” What this means for people who have had chronic tendinopathy, is hard to say. But what inferred that it could mean is that training with more frequency than I’m used to could increase the protein turnover rate in my knee and promote recovery. Given my own hypothesis that overuse injuries often come from explosive exercise and sudden acceleration of a limb which puts tremendous force on connective tissue despite low resistance, I decided that squatting more frequently with heavy enough weight to induce protein synthesis could help my knee.
I thus decreased my weight on squats, began using a high-bar Olympic depth, squat and hit the gym 3 days in a row during week one. Then week two I did the same thing and the weights that were very heavy using that style of squat went up very easily. I ended up squatting a personal best (345 pounds with no belt, no spotter, and no struggle) even compared to my wider power-lifting stance. This week I did
Starting Thursday morning I woke up with no knee pain. Today I still have no knee pain. Now, any number of things could have contributed to my apparent recovery after eight years of tendinitis. I could have just finally eaten enough protein, I could have finally slept enough, maybe I ate a magic vegetable like in a video game, it could be placebo though I imagine that would have fixed it years ago, or perhaps a wizard did it. But, the only variable I changed in my one subject sample group was exercise frequency. Now, my shoulders feel a bit beat up from squatting heavy for 5 days in a row. My lower back is pretty sore too. I certainly read less this week because the trips to the gym eat up evening time after work, but my knee feels better. I did chores around the house all morning and hardly noticed. Normally my knee remains in the fore on my consciousness when I’m picking things up, fixing things, or bumping it into stuff. It was unnoticeable today. I’ll tell you what happens in the future.