The Effect of Testosterone With / Without Training on Size, Morphology, Neuronal Wiring of Elderly Muscle (Rat Model)

How do youthful+ (probably slightly above range) levels of testosterone affect muscle size, strength, and morphology as we age? That's more or less what the authors of a recent study wanted to know when they injected aging rats with testosterone propionate and observed if/how this would affect aging in the presence or absence of resistance training.

Yes, I know, this is only a rodent study, and no one can tell for sure if similar effects will be observed in human beings... I know. What you can be sure about, however, is that an identical study is not going to be conducted with human subjects. So, all smartasses who don't give a damn about rodent studies and are unwilling to or unable to take them for what they are - basic physiological studies for hypothesis formation - please stop reading here.

Since you have not stopped reading, yet, I guess you will be interested in what the researchers from the São Judas Tadeu University and the São Paulo State University did to analyze the effects of resistance training associated with and without the concomitant the administration of exogenous significant amounts of testosterone.

Read more about studies involving TRT/HRT & co on suppversity.com:

What to expect from normalizing Testosterone

Testosterone Gel Augmens 'ur Gainz

PWO T-Increases Don't Determine Your Gainz

The Hormonal + Other Underpin-nings of Gainz

Impressive 12% T-Boost (+20% IGF1) W/ Tribulus

Low Testosterone = Low Life Expectancy?

For their study, the scientists used 30 Wistar male rats (Rattus norvegicus). With an initial age of 20 months and a study duration of 4 months, the scientists observed their hairy subjects over a period that's roughly equivalent 11.5 years in human terms (Sengupta 2013). If the results of the study are representative of what we would see in human beings, it would thus be representative of roughly 57-60-year-old human beings. The rats were divided into five groups  ...

• SEI - 20 months-old that were used as initial control (n = 6);
• SEF - 24 months-old which remained as final control of the procedures (n = 6);
• T - 20 months-old which received injections of testosterone propionate (n = 6);
• S – 20 months-old which underwent resistance training (n = 6) and
• ST - 20 months-old which were trained and received testosterone injections (n = 6).

The resistance training that was done thrice a week consisted, as it is common practice in rodent studies, of 6-8 'sets' of climbing a ladder with an inter-set rest of 2 minutes, a progressively increased weight on their backs (initial load 50% body weight).

The study used a dosages that are probably slightly higher than the equivalent of what you'd see in the average human TRT -- With respect to the previously voiced concerns about how representative the data from this rodent study would be for humans, it's important to note that the scientists chose a dosage that has previously been shown to (a) increase bone mineral density and growth hormone and (b) trigger significant increases in muscular hypertrophy in aged rats. This means that (a) it is certainly not representative of a classic testosterone cycle in bodybuilders, where the dosing will probably be significantly higher. On the other hand, the levels may be slightly higher than in conservative TRT, where T is often boosted only to "age-appropriate" (whatever that may be), not high(er) youthful levels.

The testosterone was administered in form of 200 mg/20 ml of testosterone propionate (TP), which was administered by intraperitoneal injection, twice a week (Tuesdays and Fridays), starting from the first day of the experiment in the T and ST groups. All rats were euthanized at the end of the study period, soleus and plantaris muscles were removed and prepared for histochemistry and cytofluorescence.

Figure 1: Final body weight (g) and relative muscle mass (as % of total mass) after 4 months (Krause Neto 2017).

As you can see in Figure 1 all three treatments, i.e. testosterone alone (T), training alone (S) and testosterone + training (ST), led to significant increases in the relative soleus and plantaris mass of the rodents - statistically significant were these benefits yet only for the plantaris muscle (note: unfortunately, the total lean and fat mass/body composition of the rodents was not assessed / the relative muscle mass, i.e. indiv. muscle/total mass in Figure 1, right is thus the best proxy we have).

Figure 2: Cross sectional area of type I, II-a & IIx fibers (µm²) of the soleus muscles (Kause Neto 2017); a indicates a significant difference in relation to SEI, b indicates a significant difference in relation to SEF.

For the soleus muscle, significant changes in the cross-sectional area were observed only for the type I fibers in the T, S, and ST group and the type I + type IIA fibers in the ST group.

Training alone makes rodents strong(est)

While the rodents in all three intervention groups got stronger over the 4-months study, it was not the training + testosterone (ST) group that got the strongest. Rather than that, the training only (S) group saw the greatest increases in muscle strength (+81% vs. 43% in T and 66% in ST groups).
In contrast to the maximal strength, though, the absolute training weights showed no significant inter-group difference for the T (training only) and ST (steroids + training) group, yet. With 154.3 g and 147.1 g in the S and ST group respectively, there is, however, a visible "training only" advantage.

Neither resistance training nor testosterone alone or in combination prevented the deterioration of the wiring between brain and muscle: The neuromuscular junction (NMJ) is the link between the brain and your muscles. It's deterioration and the subsequent denervation of muscle fibers often precedes (if not triggers) the onset of muscle loss. Accordingly, the absence of changes in the corresponding parameters assessed in the study at hand is a problem, because a severe degeneration of the NMJ may trigger problems you'd otherwise associate with sarcopenia, i.e. the loss of skeletal muscle mass and strength as a result of aging. This result is in line with previous resistance training studies (Deschenes 2015), but in contrast to studies which used an endurance training protocol that kept the NMJs functional (Deschenes 2016).

Hormone/Testosterone replacement therapy is one of the top-sellers in so-called/self-proclaimed anti-aging clinics. Now, the study at hand has been conducted in rodents, not men, but with its design, it is still representative of the average healthy, non-hypogonadal, but aging man who's fed up of progressive muscle and strength loss. The same guy who would pay the aforementioned clinics a visit to get testosterone shots that will up his levels to the upper end of the normal range of men in their twenties.

Steroids alone will reverse the age-related decline in muscle strength and size

If we assume for the time being, that the results Krause Neto et al. observed in this model of aging translate (not necessarily 1:1, but at least as far as the general results are concerned) to human beings, our guy from the previously described example will see results - after all, significant increases in muscle strength and size (esp. in fast-twitch muscles you'd use to lift or sprint, those muscles that deteriorate most as you age and thus affect the jacked look you may have had in your 20-40s) were observed in all three treatment groups.

Before you run to the next best HRT clinic, though, I suggest you take a look at the effects of training alone. With strength and size increases that were similar to the ones the scientists observed in the steroid (T) and steroid + training (ST) groups, the study at hand clearly confirms the potent anti-(muscle-)aging effects of a simplistic strength training (weight carrying) protocol.

Body composition probably benefits most from adding testosterone to training

A non-deniable downside to training with suboptimal testosterone levels, however, is the reduced effect on body composition. Even though the scientists didn't measure the body fat of their hairy subjects directly, the reduced reduction in body weight (-14-15% w/ testosterone vs. -10% w/ training only) clearly suggests that the rodents on "T" lost more body fat than their peers in the training-only group.

Figure 2: Relative change in lean and fat mass in response to changes in serum testosterone (calculated based on Bhasin. 2001) - you can read up on the different effect size of T on fat and muscle in my previous article "Quantifying the Big T".

And that's a result that should not surprise you if you've read my detailed elaborations on the effects of testosterone on muscle size in the "Intermittent Thoughts on Building Muscle" (go to the article overview and conclusion or read up on the different effect size of low/high testosterone on body fat and skeletal muscle in the corresponding part of the article series: "Quantifying the Big T"), in which I showcase that the effect of low testosterone on body fat is much more pronounced than its effects on skeletal muscle size.

You don't need TRT to counter the age-related loss of muscle strength and size: Yes, the effect on the rodents body composition seems to be more pronounced with youthful (or even higher) testosterone levels. Before jumping to the conclusion that you cannot get along without HRT/TRT as you age, though, there are yet three things you shouldn't forget:

• 

  Learn more about the effects of TRT on body comp (if T is low), here

  First, the strength-decline that's probably the greatest obstacle to normal physiological function in the elderly was countered at least as, if not more effectively, by training alone.  
• Second, even if the body fat loss was probably lower for the T than for the S and ST group, the muscle-to-total-body-weight ratio leaves little doubt that the training only (T) group saw improvements in body composition, too. 
• Third, a more elaborate workout that isn't limited to carrying weight upstairs for 6-8 sets may have significantly more pronounced effects on older men's body composition, would thus reduce the testosterone advantage in terms of body composition, and could, on top of that, augment the training-induced changes in muscle size and strength even further - regardless of whether you are or aren't on TRT.

So, overall, there's little doubt: the study clearly confirms the potential benefits of HRT/TRT as an anti-aging program for aging muscles, guys. It does, however, and I believe that's at least as important, also demonstrate that a little training will also go a long way - at least, if your testosterone levels suffered only the natural decline and are not rock bottom, to begin with. | Comment!

References:

• Bhasin, Shalender, et al. "Testosterone dose-response relationships in healthy young men." American Journal of Physiology-Endocrinology And Metabolism 281.6 (2001): E1172-E1181.
• Deschenes, Michael R., et al. "Effects of resistance training on neuromuscular junction morphology." Muscle & nerve 23.10 (2000): 1576-1581.
• Deschenes, Michael R., et al. "Effect of resistance training on neuromuscular junctions of young and aged muscles featuring different recruitment patterns." Journal of neuroscience research 93.3 (2015): 504-513.
• Deschenes, Michael R., et al. "Effects of exercise training on neuromuscular junction morphology and pre-to post-synaptic coupling in young and aged rats." Neuroscience 316 (2016): 167-177.
• Krause Neto, Walter et al. "Divergent effects of resistance training and anabolic steroid on the postsynaptic region of different skeletal muscles of aged rats." Experimental Gerontology 98 (2017): 80-90.
• Sengupta, Pallav. "The laboratory rat: relating its age with human's." International journal of preventive medicine 4.6 (2013): 624.

TRT - How Healthy, Lean and Muscular Will Testosterone Replacement Make You? Data from Recent Meta-Analysis

TRT - What to expect in terms of its effects on a man's body composition?

If you hear people talk about "gear" (=performance enhancing drugs | PED), you get the impression that one injection of testosterone, nandrolone and co would turn a scrawny beginner into an Olympian. Reality, however, looks much different ... in fact, the number of people who ruin their health with (often oral) designer steroids without seeing any of the results they expect has been increasing continuously over the past years (Baker. 2006a,b; Graham. 2008; Rahnema. 2014) and that despite the fact that the "Anabolic Steroid Control Act" of 2004 was originally meant to prevent exactly that from happening (Herschthal. 2012).

In spite of the fact that the introduction of today's SuppVersity article focused on PED, the purpose of the meta-analysis and thus its summary was "systematically review [...] available observational and register studies reporting data on body composition in studies" in men with low or at least suboptimal testosterone levels.

This is what most studies were lacking: Exercise to shed fat and gain muscle.

Tri- or Multi-Set Training for Body Recomp.?

Alternating Squat & Blood Pressure - Productive?

Pre-Exhaustion Exhausts Your Growth Potential

Full ROM ➯ Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Hula Hooping to Spot Reduce in the Midsection

The original meta-analysis by Corona et al. (2016) was published in the Journal of Endocrine Investigation, only a few days ago. It involved "an extensive MEDLINE, Embase, and Cochrane search [that] was performed including the following words: testosterone and body composition. And is thus not focussing exclusively on testosterone as a "new anti-obesity medication", which is how the authors refer to it in the very first sentence of the abstract, because "all observational studies comparing the effect of TS on body weight and other body composition and metabolic endpoints were considered" (Corona. 2016) in the scientists' meta-analysis. Here's an overview of the studies, their design an results, as they were summarized by Corona et al.:

• 

  Suggested Read: Testosterone Gel Augments Increases in Lean Mass Gains (+3.9kg in 6 Months) in Older Intensely Training Men, but Testim Blocks Decrease in Marker of Heart Disease Risk | more

  Valdermasson et al. (1987) - no placebo group, 10 subjects, 9 months, late onset hypogonadism (LOH) w/ baseline T of 1.8 nmol/l receiving TE 250 mg/3–4 weeks
• Rebuffé-Scrive et al. - no placebo group, 11 subjects, 1.5 months, mean age 42y, overweight/obese subjects, mean baseline T 13.8nmol/l, receiving TU 120–160 mg/day
• Forbes et al. (1991) - no placebo group, 7 subjects, 4 months, healthy, normal T levels, receiving TE 42 mg/kg/week
• Marin and Krotkievski et al. (1992) - no placebo group, 11 subjects, 1.5 months, mean age 42y, obese subjects, low T at 13.8 nmol/l, receiving TU oral 160 mg/day
• Marin and Krotkievski et al. (1996) - no placebo, 8 subjects, 3 months, mean age 42y, obese, low T at 14.1 nmol/l on T gel 250 mg/day
• Brodsky et al. (1996) - no placebo, 5 subjects with late onset hypogonadism (LOH) and T-levels of only 3.7 nmol/l on TC 3 mg/kg/2 weeks
• Katznelson et al. (1996) - no placebo, 29 subjects, 13 months, mean age 57, LOH w/ testosterone levels of 6.4 nmol/L on TE or TC 100 mg/week
• Wang et al. (1996) - no placebo, 67 subjects, for 6 months, LOH w/ starting T levels of 4.1 nmol/l taking T sublingually at 15 mg/day
• Zgliczynski et al. (1996) - no placebo, 22 subjects, 12 months, mean age 58.5y, normal elderly men with very low T (4.3 nmol/l) taking TE 200 mg/2 weeks
• Bhasin et al. (1997) - no placbeo, 7 subjects, 2.5 months, mean age 34.7y, LOH at initially 2.5 nmol/l receiving TE at a dosage of 100 mg/week
• Tan et al. (1998) - no placebo, 11 subjects, 4 months, mean age 33.3y, LOH w/ initially 5.5 nmol/l receiving TE at a dosage of  250 mg/4 weeks
• Brill et al. (2002) - no placebo, 10 subjects, 1 month, mean age 68.1y, but T-levels of 15 nmol/l treated with T patches at 5 mg/day
• Minnemann et al. (2007) - no placebo 25 subjects, mean age 57y w/ LOH and initial T levels of pretty high 14.3 nmol/l receiving TU 1000 mg/12 weeks from week 6

• 

  Suggested Read: Tribulus Boosts Testosterone (+12%), IGF-1 (+20%), Sheds 2kg (7%) Body Fat and Maintains Lean Mass in 12 Wk RCT | more

  Naharci et al. (2007) - no placebo, 24 subjects, 6 months, mean age 20.7y, low T at 5.7 nmol/l treated with mixed ester at 250 mg/3 weeks
• Saad et al. (2007) - no placebo, 28 subjects, 13 months, LOH with erectile dysfunction (ED), low  T at initially 7.5 nmol/l treated with  TU at 1000 mg/12 weeks from week 6
• Saad et al. (2008) - 27 subjects, 9 months, mean age 60y LOH with ED and initial T levels of 7.5 nmol/l treated with TU 1000 mg/12 weeks from week 6 or T gel 50mg/day
• La Vignera et al. (2009) - no placebo, 7 subjects, 3 months, mean age 58y, LOH with MetS and unknown baseline T levels treated with T gel 50 mg/day
• Moon et al. (2010) - no placebo, 133 subjects, 6 months, mean age 54y baseline T of 8.6 nmol/l treated with TU at 1000 mg/12 weeks from week 6
• Permpongkosol et al. (2010) - no placebo, 161 subjects, 13.5 months, mean age of 60.4y and LOH consulting urological center w/ T at 9.4 nmol/l on TU 1000 mg/12 weeks from week 6
• Garcia et al. (2011) - no placebo, 29 subjects, treated for 25.5 months,  mean age 55.5y, LOH and diabetes, no baseline T available, treated with TU 1000 mg/12 weeks from week 6
• Schwarz &Willix (2011) - no placebo, 56 subjects, 18 months, mean age 52.3y, overweight or obese with baseline T of 15 nmol/l receiving TC 80–200 mg/week + diet + training
• Arafa et al. (2012) - no placebo, 56 subjects, 12 months, mean age 55.5y w/ T2DM and unknown baseline T treated w/ TU 1000 mg/12 weeks from week 6
• Schroeder et al. (2012) - no plaebo 29 subjects, 4 months, mean age 71y, baseline T of 13.1 nmol/l treated with T patch 5 or 10 mg/day
• Jo et al. (2013) - no placebo, 18, 26.8 months, mean age 35.9y and suffering from Klinefelter syndrome, with low T at 3.1 nmol/l at baseline treated w/ TU 1000 mg/12 weeks from week 6

What is the Klinfelter syndrome? That's a genetic disorder that affects males. Klinefelter syndrome occurs when a boy is born with one or more extra X chromosomes. Most males have one Y and one X chromosome. Having extra X chromosomes can cause a male to have some physical traits unusual for males.

• Ko et al. (2013) - no placebo, 246 subjects, 14.7 months, mean age 58.5y  treated w/ TU 1000 mg/12 weeks from week 6
• Rodriguez-Tolrà et al. (2013) - no placebo, 50 subjects, 12 months, mean age 59.1y, LOH, mean T at baseline 10.2 noml/l treated w/ T gel 25–100 mg/day

• 

  Suggested Read: Hormonal Response to Exercise, Revisited: A Consequence, not a Determinant of Your Mood, Effort & Performance | more

  Saad et al. (2013) - no placebo, 255 subjects, 60 months, mean age 58y, mixed urological population, low T at 10.0 nmol/l treated with TU 1000 mg/12 weeks from week 6
• Tirabassi et al. (2013) - no placebo, 15 subjects, 18.5 months, mean age of 55.7y, LOH w/ baseline T levels of 5.2 nmol/l on TU 1000 mg/12 weeks from week 6
• Zitzmann et al. (2013) - no placebo, 1438 subjects, 10.5 months, mean age 49.2y, LOH w/ baseline T levels of 9.6 nmol/l on TU 1000 mg/12 weeks from week 6
• Francomano et al. (2014) - no placebo, 20 subjects, 60 monhts, mean age 57.5y, MetS and basline T of 8.3 nmol/l on TU 1000 mg/12 weeks from week 6
• Pexman-Fieth et al. (2014) - 669 subjects, 6 months, 53y, LOH on  T gel 50, 75 or 100 mg/day
• Yassin et al. (2014) - no placebo, 261 subjects, 54 months, mean age 59.5y, LOH w/ baseline T levels of 7.7 nmol/l treated w/ TU 1000 mg/12 weeks from week 6
• Zitzmann et al. (2014) - no placebo, 381 subjects, treated for 60 months, mean age 42.6y w/ LOH and low T at 5.2 nmol/l on TU 1000 mg/12 weeks from week 6

Figure 1: Influence of trial duration (a, b), age (c, d) and testosterone levels at enrollment (e, f) on weighted mean differences (with 95 % CI) of body weight (a, c, e) and waist circumference (b, d, f) at endpoint after testosterone supplementation. The size of the circles reflects the sample dimension (Corona. 2016).

Why did the scientists prefer observational trials over RCTs? "The peculiar study design of these RCTs might, as the authors point out justify the lack of efficacy of testosterone supplementation on weight parameters in previous meta-analyses. In fact, RCTs are performed under idealized and rigorously controlled conditions, which are different from everyday clinical practice. Hence, results of RCTs offer an indication of the efficacy of an intervention rather than its effectiveness in everyday practice. [...] In contrast, observational and register studies maintain the integrity of the context in which medical care is provided. As a result, whereas RCTs provide an indication of the minimal effect of an intervention, observational studies offer an estimate of the maximal one," Corona et al. write.

Table 1: Number and proportion (%) men reporting use of AAS, life-time, past 12 months and past 30 days, in different subgroups (Leifman. 2011).

All in all, we are talking about 32 out of 824 initially retrieved articles and 4513 patients whose mean age of 51.7 ± 6.1 years is yet far above that of the average PED (ab-)user whose age appears to be somewhere between 25 and 29, likely to have visited only "compulsory school" and a friend of alcohol and dietary supplements (Leifman. 2011 | see Table 1) and a very obvious result, i.e. that the supplementation of testosterone "was associated with a time-dependent reduction in body weight and waist circumference (WC).

To be more specific, "[t]he estimated weight loss and WC reduction at 24 months were −3.50 [−5.21; −1.80] kg and −6.23 [−7.94; −4.76] cm, respectively" (Corona. 2016). In addition, the provision of testosterone was, as you would probably have guessed based on previous SuppVersity articles, "also associated with a significant reduction in fat and with an increase in lean mass as well as with a reduction in fasting glycemia and insulin resistance" that were accompanied by reductions in fasting glycemia and insulin resistance (IR), as detected by HOMA-IR index - especially in studies enrolling a diabetic subject clientele at baseline (Corona. 2016).

Figure 2: Effects of TRT on blood pressure, lipids and glucose metabolism (Corona. 2016).

But isn't testosterone supplementation (TS) bad for your cholesterol and blood pressure? Even though nobody really appears to care about cholesterol on the interwebs, these days, the claim that testosterone would ruin your blood lipids and, maybe more importantly, one's blood pressure, is still propagated on "the boards". In the studies Corona et al. reviewed for their latest meta-analysis, however, the provision of exogenous testosterone (albeit in not necessarily superphysiological levels) triggered sign. improvements of the subjects' lipid profiles (reduction in total cholesterol as well as of triglyceride levels and an improvement in HDL cholesterol levels) and in both systolic and diastolic blood pressure was observed.

You're scratching your head, I see... Are you disappointed of the effect sizes? Well, you should take a closer look at the full spectrum of the results. Let's take the reduction in waist circumference, for example (Figure 3):

Figure 3: Effect of TS on waist circumference (cm) in the studies that were part of the meta-analysis (Corona. 2016).

As you can see, the latter ranged from ZERO in La Vignera (2009), who didn't even measure the waist circumference ;-) to HERO,... ah, I mean -19.6 cm in Zitzmann (2014), who studied the tolerability and effectiveness of injectable testosterone undecanoate for the treatment of male hypogonadism in a worldwide sample of 1,438 men. With a baseline waist circumference of relatively moderate 99.5 +/ - 15.25 cm, we are talking about a ~20% reduction in waist circumference, here!

Figure 4: Zitzmann et al. also found sign. improvements in mood (left) and the ability to concentrate (right) in their previously (mostly) hypogonodal subjects (Zitzmann, 2014).

Physical changes that were accompanied by significant improvements in the subjects' mood (Figure 4, right) and ability to concentrate (Figure 4, right) - results that had the authors conclude that their "study corroborates and strengthens the modern view on the desirability and efficacy of substitution therapy in men with proven hypogonadism, also in a “real-life” setting" (Zitzmann. 2014).

You to know more about superphysiological doses?

If that's not "good enough" for you, let me remind you of my previous review of a seminal paper by Bhasin et al.  who conducted (to my knowledge) the only "dose-escalation" study that comes remotely close to being a "PED"-RCT, i.e. a controlled trial that may give us some insights into the effects T at dosages that are used by performance enhancing drug users would have.

Figure 5: Dose response relationship of muscle gain (in kg) per mg of testosterone enanthate (left) , the white line indicates a dose that would probably have produce testosterone levels identical to baseline; and relative change in lean and fat mass in response to changes in serum testosterone levels (right | Bhasin. 2001)

While I've reprinted the most important data in Figure 5, I'd still suggest you take a closer look at the corresponding SuppVersity Classic article, if you want to learn more - especially about the interpretation of the graph on the right hand side that shows the relative change in lean and fat mass in response to changes in serum testosterone levels.

Overview of factors controlling muscle gains (Moussa. 2012)

If you want to know what's possible in healthier people, I suggest you go back to my articles in the "Intermittent Thoughts on Building Muscle" series. More specifically, the articles "Zoning in on "The Big T" - Does Testosterone (Alone) Build Muscle?" (read it), "Quan-tifying "The Big T" - Do Testosterone Increases Within the Physiological Range Really Matter? And How Much is too Much?" (read it) and the conclusion "Exercise, mTOR/AKT/MAPK, IGF-1, Testosterone, Estrogen, DHT, Nutrition, Supps & Sleep" (read it) from which I have copied the overview of different mechanism that contribute to / control muscle growth on the right | Comment

References:

• Baker, Julien S., Michael Graham, and Bruce Davies. "Gym users and abuse of prescription drugs." Journal of the Royal Society of Medicine 99.7 (2006a): 331-332.
• Baker, J. S., M. R. Graham, and B. Davies. "Steroid and prescription medicine abuse in the health and fitness community: A regional study." European journal of internal medicine 17.7 (2006b): 479-484.
• Bhasin, Shalender, et al. "Testosterone dose-response relationships in healthy young men." American Journal of Physiology-Endocrinology And Metabolism 281.6 (2001): E1172-E1181.
• Corona, G., et al. "Testosterone supplementation and body composition: results from a meta-analysis of observational studies." Journal of Endocrinological Investigation (2016): 1-15.
• Graham, Michael R., et al. "Anabolic steroid use." Sports medicine 38.6 (2008): 505-525.
• Herschthal, Adam. "From Rats to Riches: How the Anabolic Steroid Control Act of 2004 Unjustly Punished the Gym Rat and How a New Prescription Is the Road to Salvation." Syracuse L. Rev. 63 (2012): 437.
• La Vignera, S., et al. "Andrological characterization of the patient with diabetes mellitus." Minerva endocrinologica 34.1 (2009): 1-9.
• Rahnema, Cyrus D., et al. "Anabolic steroid–induced hypogonadism: diagnosis and treatment." Fertility and sterility 101.5 (2014): 1271-1279.
• Zitzmann, Michael, et al. "IPASS: a study on the tolerability and effectiveness of injectable testosterone undecanoate for the treatment of male hypogonadism in a worldwide sample of 1,438 men." The journal of sexual medicine 10.2 (2013): 579-588.

Tribulus Boosts Testosterone (+12%), IGF-1 (+20%), Sheds 2kg (7%) Body Fat and Maintains Lean Mass in 12 Wk RCT

Could a high dose of purified saponin tribulus extract as it was obviously used in the study at hand actually be a valid TRT alternative or even option? 

No, this is not the 2015 study in trained boxers that found similarly surprising, because impressive benefits from tribulus terrestris (TT) supplementation (read it). It's a new study from the Jerzy Kukuczka Academy of Physical Education in Katowice, Poland (Wilk. 2016) that has no direct link to the previously discussed study from the  Shanghai University of Sport Affiliated School of Sports in China.

And even though, the aim, i.e. to determine the effects of steriodal saponins from tribulus terrestris on the blood concentration of testosterone (T), GH and IGF-1 was similar, the overall design of the study was significantly different.

Don't forget to work out - Without exercise you're not going to get lean and jacked, bro!

Tri- or Multi-Set Training for Body Recomp.?

Aug '15 Ex.Res. Upd.: Nitrate, Glycogen, and ...

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BFR-Preconditio- ning Useless for Weights?

Study Indicates Cut the Volume Make the Gains!

While the previously discussed study by Ma et al. (2015) was conducted with young athletic individuals, Wilk et al. deliberately chose 14 men between the age of 45 and 60 years, i.e. exactly those years in a man's life over the course of which the natural hormone production starts to decline significantly.

Table 1: How to recognize your T-levels are declining (from Matsumoto. 2002).

Over twelve weeks, the subjects who were normal-to-overweight with a body mass index of 25–33, and body fat content between 23–30%, received either...

• experimental group: steroidal saponins (TT) - for the first six weeks three capsules (900 mg) per day in split doses (2x capsules were ingested in the morning on an empty stomach, 600 mg, and one at bedtime, 300 mg) and twice the dose, i.e. 6 capsules (1,800 mg) were ingested per day in split doses (4x capsules in the morning on an empty stomach, 1,200 mg, and 2x capsules at bedtime, 600 mg), or 

What's the use of the "front load", i.e. taking more in the AM vs. PM? That's a question I just received from Peter via Facebook. Good question, but one the scientists do not answer. So I'd have to speculate that they may have intended to mirror the natural 24h (=circadian) rhythm of testosterone which peaks in the AM and declines over the day to re-increase over night and peak again in the AM. What is particularly interesting about this rhythm, by the way, is that it - or rather the peaks in the AM, are lost as you age (see Figure on the left | Bremner. 1983).

• control group: placebo (CON) - in the form of gelatin capsules using the same supplementation protocol as it was prescribed in the experimental group 

And even though all subjects participated in a physical activity program over the 12 week study period, the workouts the scientists describe as follows,...

"Get leaner, more muscular and hornier than ever before" - That's probably the promise on the T-booster someone will release after reading this SuppVersity Classic article and sourcing an inferior Shilajit extract on Alibaba. Is that going to be a waste of time - just as the majority of the tribulus products on the market, which are lightyears away from providing grams of pure saponines on a multiple serving per day basis | learn more.

"4 training sessions per week, with 2 sessions directed at the improvemnt of anaerobic power (resistance exercise), while 2 consisted of aerobic endurance exercise. Aerobic training was performed on a stationary cycle ergometer, starting with 30 minutes of continuous exercise at an intensity of 70–75% of maximum heart rate (HR max). Every two weeks, the work volume was increased by 5 minutes in order to reach 60 minutes in the last two weeks of the experiment. Strength training had a holistic aproach, involving all major muscle groups (the back, chest, abdomen, arms and lower limbs). For the first four weeks, exercises were performed in 3 sets of 8–12 reps with the resistance equal to 60–70% of 1RM and 2 min rest periods between sets. During the experiment, the number of sets of each exercise increased from 3 to 4 sets in weeks 5–8, and respectively to 5 sets in weeks 9–12 for each exercise," (Wilk. 2016)

was of course not the same as the one in the previously discussed Chinese study. In conjunction with the standardized isocaloric (same energy content) mixed diet containing 55% carbohydrate, 20% protein, 25% fat, the workouts are still an important means of standardizing / reducing inter-group differences that could otherwise arise due to personal exercise and / or diet preferences.

Figure 1: Relative changes in blood lipids, GH, IGF-1 and testosterone (Wilk. 2016).

The results of the scientists' two series of laboratory tests (independent tests were conducted at the beginning and after 12 weeks of the intervention), revealed a statistically significant effect of the intervention on the following variables: T-Ch (η2 = 0.542), HDL-Ch (η2 = 0.522), LDL-Ch (η2 = 0.587), T (η2 = 0.603), IGF-1 (η2 = 0.512) and GH (η2 = 0.621).

Figure 2: Relative changes in body composition; effect sizes and p-values (Wilk. 2016).

Effects of which you will probably pleased to hear that they went hand in hand with significant decreases in total body fat (TBF) total body mass (BM) and borderline significant effects on the fat-free mass (muscle, organ and bone mass) of the subjects - an observation of which the scientists say that it "indicate[s] that treatment or supplementation of individual hormone deficiencies can be a successful form of counteracting the aging process" - an aging process that is evidenced by increasing body fat levels, decreasing amounts of fat-free mass and concomitant deterioration of blood lipids and blood glucose (the latter was unfortunately not measured in the study at hand).

Wtf!? What kind of tribulus was that? I wish I could tell you that, but a brand name or other specifics are not mentioned in the publicly financed study from Poland.

Make no mistake about it, the impressive increases in free T in Brown's often miscited 2001 study from which I took this figure were due to a combination of the prohormone androstenediol with tribulus and other herbs. To ascribe the T-increase to TT is idiotic.

What I can tell you is that the results are in line with a 2009 study by Milasius, et al. who used food a commercial supplement Tribulus from Optimum Nutrition, USA, and observed positive effects on the acid-base equilibrium after short-term, high intensity anaerobic exercise in competitive athletes. The study at hand apparently used a more pruified steroidal saponin supplement, however, and observed similar effects as Brown et al. (2001), who supplemented tribulus alongside 300mg of the prohormone androstenediol and found - not to anyone's surprise, probably a significant effect on serum testosterone concentration in both young and older men (see Figure to the right).

Since no such effects were observed in the often cited study by Neychev, et al.  (2005) in allegedly much younger subjects, the question future studies will have to answer is whether that's due to an (subject-)age- or dosage / otherwise supplement-related difference between the high dose of (probably) pure saponins used in the study at hand and the relatively low dose of Bulgaria TT (200mg/day) with 60% saponins that was used by Neychev, et al. in 2005 | Comment!

References:

• Bremner, William J., Michael V. Vitiello, and Patricia N. Prinz. "Loss of Circadian Rhythmicity in Blood Testosterone Levels with Aging in Normal Men*." The Journal of Clinical Endocrinology & Metabolism 56.6 (1983): 1278-1281.
• Brown, Gregory A., et al. "Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men." Journal of the American College of Nutrition 20.5 (2001): 520-528.
• Matsumoto, Alvin M. "Andropause clinical implications of the decline in serum testosterone levels with aging in men." The Journals of Gerontology Series A: Biological Sciences and Medical Sciences 57.2 (2002): M76-M99.
• Milasius, K., R. Dadeliene, and Ju Skernevicius. "The influence of the Tribulus terrestris extract on the parameters of the functional preparedness and athletes’ organism homeostasis." Fiziol Zh 55.5 (2009): 89-96.
• Neychev, Vladimir Kostadinov, and Vanyo Ivano Mitev. "The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men." Journal of ethnopharmacology 101.1 (2005): 319-323.
• Wilk, Michał, et al. "Endocrine Responses to Physical Training and Tribulus Terrestris Supplememtation in Middle-Age Men." Central European Journal of Sport Sciences and Medicine 13.1 (2016): 65-71.

T-Boosters Revisited: Maca & G. Cola Boost Testosterone by More Than 125% and 300% While Increasing Libido

We still need human studies to confirm the results of the studies to call maca and garcinia cola "proven T-boosters"!

Before you get all-too-excited; let's be clear about this: An increase in natural testosterone production will not produce the same increase in muscle mass and reduction in body fat as injectable testosterone. As I've explained in two previous articles ("Understanding the Big T", "Quantifying the Big T"), the difference lies in small constant (T-booster) vs. extreme and slowly declining increases in testosterone (T-injection | see Figure 1). If you take a look at the dose-response graph I created for the former article, you will yet realize that this does not mean that a significant boost of low-ish T-levels wouldn't have benefits - especially on your body composition.

With that being said, there's a second thing I must say right away: both studies I will discuss in today's article are rodent studies (rats to be specific) and need confirmation in humans - follow up studies that confirm the >100% increase in testosterone with really high doses of MACA extracts and >300% increase in response to high dose garcinia cola supplementation.

Don't forget to work out - Without exercise you're not going to get lean and jacked, bro!

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Whut? No, those are no typos. The treatments did in fact more than double the total testosterone concentrations of the rodents in the studies from the Graduate School of Life and Environmental Sciences of the Osaka Prefecture University (Ohta. 2016) and Walter Sisulu University in South Africa (Sewani-Rusike. 2016).

• MACA - Lepidium meyenii (maca) is a plant growing in Peru’s central Andes, of which you've certainly heard that it has traditionally been used for enhancing fertility and reproductive performance in domestic animals and human beings.
  
  In their latest study, scientists from the Graduate School of Life and Environmental Sciences of the Osaka Prefecture University (Ohta. 2016) examined whether feeding a hydroalcoholic extract powder of maca for 6 weeks would affect the weight of the reproductive organs, serum concentrations of testosterone and luteinising hormone (LH), number and cytoplasmic area of immunohistochemically stained Leydig cells, and steroidogenesis of cultured Leydig cells in 8-week-old male rats.

  

  Figure 1: Effects of feeding maca extract on serum testosterone and LH concentrations in male rats (Ohta. 2016).

  As you already know, the scientists observed highly significant improvements of the testosterone levels (see Figure 1). In addition, feeding the extract powder increased weight of seminal vesicles and cytoplasmic area of Leydig cells when compared with controls.
  
  The best news is that this happened in the absence of increases of prostate gland weight, and without increases in serum LH concentration that would suggest that the leading cells, the number of which didn't increase either, wouldn't produce T as effectively, any longer. This also implies that the provision of what would be ~12g of MACA per day (2% of the diet were a proprietary MACA extract called MACAXS™ | no sponsorship or support declared) increased the testosterone production by Leydig cells significantly - a result and mechanism the scientists were able to confirm in vitro.

But isn't there human data, already, which refutes these results? To my knowledge the answer to this question is "NO". Not because there were no studies on the effects of maca, for example, on libido and testosterone, but rather because these studies used, just like a study by Gonzales, et al. from 2002 doses that were not just >5x lower than the human equivalent in the study at hand, but also based on regular gelatinized maca powder, instead of an extract, as it was used by Ohta, et al. Against that background it is, by the way, even more surprising that Gonzales et al. still observed a beneficial effect on the libido of their 21–56 year-old male subjects.

• Garcinia cola - Commonly known as bitter kola due to its bitter taste, the garcinia cola nut is traditionally served as refreshment. Medicinally, however, it has been used for centuries to treat abdominal pain, cough, laryngitis, liver disease infections and erectile problems (Irvine, 1961; Odebunmi et al., 2009). In previous studies, these effects have been ascribed to phytochemicals like biflavonoids, xanthones, triterpenes, cycloartenols and benzophenones (Terashima. 2002; Adaramoye. 2005 & 2006), agents of which scientists have found only recently that they can increase testosterone and male reproductive function, as well (Farombi. 2013). Sewani-Rusike et al. were inspired by the results Farombi et al. published in the Journal of Ethnopharmacol and investigated the effects of different doses of a crude extract of G. kola on male sexual function after subchronic and chronic treatment periods at different sublethal doses (the lethal dose is 5000mg/kg in rats and 30g/kg in humans).
  

  

  Figure 2: Testosterone, LH and FSH levels (left) as well as markers of sexual function, i.e. mount latency (ML), intromission latency (IL), the number of mounts and intro-missions (Sewani-Rusike. 2016). 

  As you can see in Figure 2 there's an initially surprising disconnect between the effects on testosterone and the markers of sexual function (lower mount and intromission latency indicate more horny). Since previous studies (also in humans) have already shown that there's this disconnect between normal-high and high testosterone levels and their effect on libido, the results are eventually not as surprising as you would expect. Therefore, the observation that lower doses were eventually the most effective when it comes to increasing the components of libido, erection and ejaculation, is not really surprising. Neither is the fact that the scientists observed increases in testicular weights, and sperm count, with no change in motility and gonadotropin levels.
  
  Since the gross testicular histology was not affected by the 70% ethanolic extract of garcinia cola the scientists used in this study, the only thing that's missing to call garcinia cola a "proven T-booster" is the lack of human studies investigating its effects and safety at human equivalent doses of 16, 32, and 64 mg/kg body weight.

Tribulus is Good for Something: 1.25 g/day Modulate IGF-1 Availability and Alleviate Muscle Damage While Promoting Anaerobic Performance of Intensely Trained Male Boxers | more.

Bottom  line: Even though I may sound like a broken record, I want to repeat that doubling and even quadrupling your testosterone levels will not double, let alone quadruple your strength and size gains. And still, if you're looking for a T-booster to get your suboptimal T-levels back in range, the studies by Ohta et al. (2016) and Sewani-Rusike et al. (2016) provide two new reference points with respect to potentially effective ingredients - ingredients of which only one, namely MACA, has already been used extensively, but at far too low doses (remember, the HED in the study at hand was ~12g of an extract, which is not the "normal" MACA powder you can buy everywhere) in currently and previously available T-boosters | Comment on Facebook!

References:

• Adaramoye, O. A., et al. "Comparative study on the antioxidant properties of flavonoids of Garcinia kola seeds." Pakistan Journal of Medical Sciences 21.3 (2005): 331.
• Adaramoye, O. A., and E. O. Adeyemi. "Hypoglycaemic and hypolipidaemic effects of fractions from kolaviron, a biflavonoid complex from Garcinia Kola in streptozotocin‐induced diabetes mellitus rats." Journal of pharmacy and pharmacology 58.1 (2006): 121-128.
• Farombi, Ebenezer O., et al. "Hepatic, testicular and spermatozoa antioxidant status in rats chronically treated with Garcinia kolaseed." Journal of ethnopharmacology 146.2 (2013): 536-542.
• Gonzales, G. F., et al. "Effect of Lepidium meyenii (MACA) on sexual desire and its absent relationship with serum testosterone levels in adult healthy men." andrologia 34.6 (2002): 367-372.
• Ohta, Y., et al. "Feeding hydroalcoholic extract powder of Lepidium meyenii (maca) increases serum testosterone concentration and enhances steroidogenic ability of Leydig cells in male rats." Andrologia (2015).
• Sewani‐Rusike, C. R., N. Ralebona, and B. N. Nkeh‐Chungag. "Dose‐and time‐dependent effects of Garcinia kola seed extract on sexual behaviour and reproductive parameters in male Wistar rats." Andrologia (2015).