Download Fitness Tools

Nucleotides are building blocks of our DNA and RNA and - as preliminary evi- dence suggests - ergogenic supplements for athletes on intense workout routines. In that, "intense" is the key word, 'cause normally our bodies can produce enough nucleotides on their own.

Nucleotides? Yeah, this are the small subunits, of nucleic acids like DNA and RNA. They are essential to nearly all biological processes including DNA and RNA synthesis, coenzyme synthesis, energy metabolism, cellular signaling and protein homeostasis and can be produced by our bodies "on demand" via de novo synthesis. Just like some of the non-essential amino acids which may become essential under certain circumstances, though, our bodies' own nucleotide production facility are often incapable of meeting the needs of rapidly proliferating tissues.

As Sterczala et al. (2015) point out in the introduction to their latest paper in the Journal of Strength and Conditioning Research, a salvage pathway is therefore required to synthesize nucleotides from exogenous sources (Gil. 2002).
As such, dietary nucleotides are necessary to maintain immune function, tissue growth and cellular repair. Sounds familiar? Yeah, all of those functions are affected by exercise, which can (at least temporarily) significantly increase one's nucleotide demands to levels that cannot be supplied by endogenous (=the body's own) synthesis, alone. A recent study which shows that the blunted hypertrophic response in aged skeletal muscle is associated with decreased ribosome biogenesis even suggest that this may be one of the reasons old muscle won't grow (Kirby. 2015). Consequently, there has been a growing interest in the potentiaL implications of exogenous nucleotide supplementation on exercise-induced immune
responses.

"Aside from increases in salivary immunoglobulins, McNaughton et al. (2006 & 2007) have observed a decreased cortisol response to exercise, which would partially explain the reduced immunosuppression. Animal models have observed similarly attenuated cortisol responses to stressful stimuli (Palermo. 2013, Tahmasebi-Kohyani. 2012). Given the roles of cortisol in gluconeogenesis and glycogenolysis, a reduced cortisol response may indicate a reduction in the metabolic stress of the exercise bout as a result of nucleotide supplementation. In the days following stressful exercise, [chronically (!) | see red box to learn why this is important] elevated cortisol levels could impair recovery, as cortisol can increase protein degradation and inhibit protein synthesis (Hickson. 1993; Kraemer. 2005)" (Sterczala. 2015). 

So, while we don't want to block the cortisol response to exercise altogether (here's why), Sterczala et al. are right: Attenuating or controlling it may quite beneficial. Especially if this attenuation occurs in the days after the exercise-stressor, when you want your cortisol levels to return to normal. Unfortunately, Ostojic et al. (2012 & 2013) and McNaughton et al. (2006 & 2007) who have already demonstrated the beneficial effects of nucleotide supplementation following acute exercise, did not control for the immune and cortisol response during the recovery period after the exercise stimulus. In addition, their studies involved cycling and running exercises which are, as Sterczala et al. rightly point out, "quite different in terms of muscle recruitment and metabolic demands when compared to heavy resistance exercise" (Sterczala. 2015). Therefore, the effects of nucleotide supplementation on the response patterns to resistance exercise are currently unknown and thus the perfect research object for a new study - Sterczala et al.'s new study.
Said study used a double blinded, cross-over, within subject design, with ten young men and ten women participating in the acute heavy resistance exercise protocol (AHREP) following a loading period with either a nucleotide supplement or placebo supplementation phase.

Do you remember that protease supple- mentation (e.g. 1,000mg Bromelain) has recently been shown to have ergogenic effects in athletes, too?

"The nuBound® (Nu Science Laboratories, Inc., Boston, MA [the sponsor of the study]) supplement contains dietary nucleotides, which are extracted from yeast (saccharomyces cerevisiae). During the supplement treatment cycle, subjects took two capsules of nuBound® daily, one upon waking, and one following exercise. The two capsules (1000mg) contained 278mg of dietary nucleotides, 375mg amino acids (l-glutamine, l-methionine, l-lysine), riboflavin (4.5mg), folate (400mcg), biotin (188mg) and pantothenic acid (12mcg). Other ingredients included fructo-oligosaccharides (chicory root), inositol and sodium citrate.

During the placebo cycle, subjects followed a dosing schedule identical to the supplement cycle. The placebo capsules were identical in size, shape and color to the nucleotide supplement but contained only lactose and magnesium stearate. During the first treatment cycle, subjects recorded their daily dietary intake on a diet log. The log was then used to help subjects replicate their diet during the second treatment cycle. Subjects also replicated their activity protocol during the study for each cycle" (Sterczala. 2015)."

Each cycle (placebo - PL; nucleiotides - NT) began with a two week loading phase in which subjects took the supplement while maintaining their normal exercise routines. At the beginning of the third week, an acute heavy resistance exercise protocol (AHREP) was completed. To assess the effects on recovery, subjects reported to the laboratory 24, 48 and 72 hrs following the AHREP for additional blood draws and performance testing. Before and after the the acute heavy resistance exercise protocol (AHREP), and at 24, 48, and 72 hrs thereafter, blood samples were analyzed for cortisol, myeloperoxidase, and absolute neutrophil, lymphocyte and monocyte counts. Creatine kinase was analyzed pre-AHREP and at 24, 48, and 72 hrs post-AHREP. Performance measures, including peak back squat isometric force and peak countermovement jump power were also analyzed.

Figure 1: Effects of nucleotide (NT) and placebo supplement (PL) preload for two weeks on cortisol (~stress) and creatine kinase (~muscle damage) response to exercise (Sterczala. 2015).

As you can see in Figure 1 the nucleotide supplementation resulted in significant (P ≤ 0.05) decreases in observed cortisol and MPO acutely following the AHREP, as well as significantly lower CK values at 24 hrs post. The AHREP significantly affected leukocyte counts, however, no treatment effects were observed (which is in contrast to previous studies, but in view of the disconnect between this markers and practically relevant immune outcomes, like the susceptibility to infection, irrelevant).

Figure 2: While the improved cortisol and CK are nice to see, only the accelerated force recovery in the isometric back-squat test may actually be practically relevant for athletes (Sterczala. 2015).

What is significantly more important than any of these markers of muscle stress, muscle damage or immune function is the fact that the the nucleotide supplement increased the peak force in the back squat isometric force test (albeit not the power during counter-movement jumps) immediately post AHREP and at 24 hrs and 48 hrs (see Figure 2). After all, changes like these, and not improvements in markers of whatever are what really matters for athletes.
References:

• Gil, A. "Modulation of the immune response mediated by dietary nucleotides." European Journal of Clinical Nutrition 56 (2002): S1-4.
• Hickson, et al. "Exercise and inhibition of glucocorticoid-induced muscle atrophy." Exercise and sport sciences reviews 21.1 (1993): 135-168.
• Kraemer, William J., and Nicholas A. Ratamess. "Hormonal responses and adaptations to resistance exercise and training." Sports Medicine 35.4 (2005): 339-361.
• Kirby, et al. "Blunted hypertrophic response in aged skeletal muscle is associated with decreased ribosome biogenesis." Journal of Applied Physiology 119.4 (2015).
• Mc Naughton, L., D. J. Bentley, and P. Koeppel. "The effects of a nucleotide supplement on salivary IgA and cortisol after moderate endurance exercise." Journal of sports medicine and physical fitness 46.1 (2006): 84.
• Mc Naughton, Lars, David Bentley, and Peter Koeppel. "The effects of a nucleotide supplement on the immune and metabolic response to short term, high intensity exercise performance in trained male subjects." Journal of sports medicine and physical fitness 47.1 (2007): 112.
• Ostojic, Sergej M., and Milos Obrenovic. "Sublingual nucleotides and immune response to exercise." J. Int. Soc. Sports Nutr 9 (2012): 31.
• Ostojic, Sergej M., Kemal Idrizovic, and Marko D. Stojanovic. "Sublingual Nucleotides Prolong Run Time to Exhaustion in Young Physically Active Men." Nutrients 5.11 (2013): 4776-4785.
• Palermo, Francesco Alessandro, et al. "Effects of dietary nucleotides on acute stress response and cannabinoid receptor 1 mRNAs in sole, Solea solea." Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 164.3 (2013): 477-482.
• Sterczala, et al. " The Physiological Effects of Nucleotide Supplementation on Resistance Exercise Stress in Men and Women." Journal of Strength and Conditioning Research (2015): Publish Ahead of Print.
• West, Daniel WD, and Stuart M. Phillips. "Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training." European journal of applied physiology 112.7 (2012): 2693-2702.

Don't worry, this exercise is not going to reverse all the effects of your training. Still, in view of the intriguing results of the study at hand, it would be interesting if the fiber-type unspecific effects in powerlifters are reversed when you stop powerlifting / exercise altogether and/or start lifting with higher volumes and lower intensities (bodybuilding style volume training).

There are visible and invisible differences between bodybuilders, powerlifters and normal men. The former ones are so obvious that it wouldn't be very interesting to address them in a study. The latter, on the other hand, are, other than you'd expect, hardly researched, but - as the results of a recent study from the Manchester Metropolitan University, and a bunch of other European Universities and research centers shows - more pronounced and significantly more fundamental than some of you may have thought.

As Meijer et al. point out in the introduction to their soon-to-be-published paper in the peer-reviewed scientific journal Experimental Physiology, the performance of a power athlete is largely determined by two traits: the maximal force and power generating capacity of the recruited muscles, and the ability to maintain force and power for a prolonged period of high intensity efforts.
Needless to say that the peak muscle power and force will to some extent dependent on muscle volume and physiological cross-sectional area of the muscle, respectively. In accordance with the above definition of what one's power will depend on, though, the mitochondrial density in the recruited muscle fibres does yet figure as well. I mean, you don't want to run out of steam on your 3rd rep of squats, do you? That's what I thought. Thus, Meijer et al. are right to point out that "[i]deally, an  athlete seeks to maximize both muscle power and endurance" (Meijer. 2015).

Myostatin Limits Muscle Hypertrophy in Everyone! Even Normal Gymrats May Benefit from Blockers, if any of them Actually Worked  Learn more!

The problem with this maxim, however, is that you cannot maximize both, the fibre cross-sectional area (FCSA) and its mitochondrial density. In fact, studies suggest that the FCSA at a given mitochondrial density is limited by the maximal extracellular oxygen tension (Van der Laarse et al., 1997; Wessel et al., 2010) or the myonuclear domain sizes (learn more).

It is thus only logical that studies on myostatin negative animals show that limit the amount of hypertrophy beyond which it becomes disadvantageous for sustainable power (learn more). Weak big, vs. small(er), yet strong muscles. That sounds like powerlifting vs. bodybuilding, right?
Well, that's obviously what Meijer et al. thought, as well, when they phrased the following hypotheses about the way the muscle fiber specific tension (F0) of 12 male bodybuilders (BB | BB: 29.8 ± 4.8y; 177.8 ± 4.1 cm; 91.7 ± 13.4 kg), 6 male powerlifters / power athlete (PA | 23.4 ± 3.9 y; 185.0 ± 4.3 cm; 103.0 ± 7.3 kg) and 14 non-competitive / weight lifting controls (C | 24.0 ± 3.5 y; 180.9 ± 5.3 cm; 77.9 ± 6.3 kg) differ in the introduction to their latest paper:

"PAs is characterized by high-intensity low-volume resistance training with supplemental aerobic exercise. Since BBs train for bulk and PAs for function we hypothesize that fibres from PAs will have a higher specific power and F0 than those from BBs. We expect an increase in specific power and F0 in PAs and BBs (for BBs especially in type II fibres) compared to C." (Meijer. 2015). 

To test whether this hypothesis is correct, the researchers compared muscle fibre contractile properties of biopsies taken from m. vastus lateralis of 12 bodybuilders (BB; low- to moderate-intensity high-volume resistance training), 6 power athletes (PA; high-intensity low-volume combined with aerobic training) and 14 controls (C). To do that you have to take samples from the muscle and test the maximal isotonic contractions on a single muscle fibre in vitro.

Figure 1: Typical examples of three IIA muscle fibres. Circles represent the measured force-velocity data. The continuous line shows the fitted force-velocity curve and the dashed line shows force-power curve (top). Specific tension of skinned m. vastus lateralis fibres is inversely related to muscle fibre cross-sectional area (bottom) - For both rows of data: Non-resistance trained controls (left), bodybuilders (middle), power athletes (right | Meijer. 2015).

As the data in Figure 1 shows, the scientists' analysis of their subjects' muscle fibers produced unsurprising and surprising results:

• BBS have larger muscle fibers (unsurprising) - The fibre cross-sectional area (FCSA) was 67% and 88% (P<0.01) larger in BB than in PA and C, respectively.
• There's no difference in fiber size between C and PA (surprising?) - Unlike the difference between bodybuilders, power athletes and control, the existing difference in fiber size between PA and C did not reach statistical significance. 
• BB and PA fibres are stronger (unsurprsing) - BB and PA fibers developed a higher maximal isometric tensions (32%, 50%, P < 0.01) than those of C. 
• BB & C fibers are significantly weaker than PA fibers (unsurprising) - The specific tension (F0) of BB fibres was 62% and 41% lower than that of PA and C fibres (P < 0.05), respectively. 
• The increased peak power of PA fibres was not related to fibre type (surprising) - Irrespective of fibre type, peak power (P) of PA fibres was 58% higher than that of BB fibres (P < 0.05), while BB fibres –despite considerable hypertrophy- had similar PP as C fibres. 

With the latter result standing in contrast to the long-held believe that training induced changes in fiber composition like an increase in the proportion of power-specific MHC IIa,b fibers in power athletes and an increase in "enduring" type II fibers (MHC IIx) in bodybuilders were responsible for the strength and power differences, the study at hand provides initial evidence that that the effects of the way you train go way beyond selective type IIa,b vs. type IIx hypertrophy.
References:

• Jürimäe, Jaak, et al. "Differences in muscle contractile characteristics among bodybuilders, endurance trainers and control subjects." European journal of applied physiology and occupational physiology 75.4 (1997): 357-362.
• Meijer et al. "Single muscle fibre contractile properties differ between bodybuilders, power athletes and controls." Experimental Physiology (2015): Accepted article.
• Van Der Laarse, W. J., et al. "Size principle of striated muscle cells." Netherlands journal of zoology 48.3 (1997): 213-223.
• Van Wessel, T., et al. "The muscle fiber type–fiber size paradox: hypertrophy or oxidative metabolism?." European journal of applied physiology 110.4 (2010): 665-694.

Don't forget to wait 4 minutes after your pre-sprint squats, otherwise the post-activation "bonus" is not going to show its maximal performance benefits.

Time for a brief review of the latest performance relevant exercise science from the Concordia University, the Palacky University in Olomouc and the University of Granada. Three studies that are packed with potentially performance-enhancing science on the post-activation effects of squatting before sprinting, the effect of different ways of holding your dumbbells during split and squats an walking lunges on muscle activity and the usefulness of adding bands and chains to your training regimen.

So, I guess it's best if I don't keep you on the not so tender hooks of suspense any longer and give you the elevator pitch of all three studies:

• Squat Before You Sprint (Wyland. 2015) - It's not exactly "news" that applying accommodating resistance combined with isoinertial resistance can effectively improve neuromuscular attributes important for sport performance.
  
  What is news, though, is the fact that short sprints can be acutely enhanced after several sets of back squats. News that was generated in a study involving twenty recreationally resistance trained males (age 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) who performed pre-post testing on 9.1 meter sprint time under three different conditions:

  "[O]n three separate days subjects either sat for five minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1RM with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1 meter sprint testing. Post-testing for 9.1 sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post 3-min, and Post-4min)" (Wyland. 2015).

  Repeated-measures ANOVA statistical analyses revealed no significant changes in sprint time across post-testing times during the CTRL and STND condition.
  

  Figure 1: Mean sprint times (s) in all three conditions (Wlyand. 2015).

  During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal post-activation potentiation effect to increase neuromuscular performance. "Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is the goal," Wyland et al. conclude.
• Hold the DBs Right, When You Split Squat or do Walking Lunges (Stastny. 2015) - If you are like me and you don't switch off your brain while you're training you will have noticed that the side on which you hold the dumbbell (assuming you don't do them unilaterally loaded, i.e. with weight on both sides)during split squats or walking lunges can have a significant effect on "where", i.e. in which muscle, you feel the exercise.
  
  According to a recent study by Stastny et al. this effect may be mediated by the effect the positioning of the dumbbells will have on the activity of the muscles which was assessed by the Polish researchers in both trained (RT) and untrained (NT) individuals via EMG measures.
  

  Figure 2: EMG during the eccentric phase and kinematics of all exercises (Stastny. 2015).

  What Stastny et al. found was that the effect of DB positioning was significantly more pronounced in the previously trained subjects (RT) in which the researchers observed a higher eccentric Gluteus Medius (Gmed) amplitude (p<0. 001, η²=0.46) during all exercises and a higher eccentric VL amplitude (p<0.001, η²=0.63) during contralateral walking lunges.
  
  Further differences were found between contralateral (=holding the weight on the opposite side) walking lunges and ipsilateral (=holding the weight on the same side) walking lunges in both the RT (p<0.001, η²=0.69) and NT groups (p<0.001, η²=0.80), and contralateral walking lunges resulted in higher eccentric Gmed amplitudes. In other words, if you want to train the Gluteus Medius, the broad, thick, radiating muscle, situated on the outer surface of the pelvis, hold the weight on the opposite side of the trained leg. 
• Use Chains or Bands to Power Up (Soria-Gila. 2015) - The advice is not actually new. Specifically, the tip to use bands to "power up" was in the waredownloadsoft news before. In view of the fact that my own gym experience tells me, though, that hardly anyone follows this advise, it may be worth taking another look at the data in Figure 3.
  

  Figure 3: Forest plot of the results of the meta-analysis of random effects showing the difference in mean weighted 1RM and 95% CI detected for the bench press, leg press, back squat and squat (5.03 kg; 95% CI: 2.26–7.80 kg; Z = 3.55; P < 0.001) in upper body training and lower body training subjects. Gray squares indicate the intervention effect (Soria-Gila. 2015).

  The data was collected by scientists from the University of Granada in Spain, who reviewed seven studies involving 235 subjects and concluded that "VRT [variable resistance training using bands and chains] le[a]d[s] to a significantly greater mean strength gain (weighted mean difference: 5.03 kg; 95% CI: 2.26–7.80 kg; Z = 3.55; P < 0.001) than the gain recorded in response to conventional weight training" (Soria-Gila. 2015).
  
  Now this is the point where you're supposed to acknowledge that "[l]ong-term VRT training using chains or elastic bands attached to the barbell emerged as an effective evidence-based method of improving maximal strength both in athletes with different sports backgrounds and untrained subjects" (Soria-Gila. 2015) and go get your bro's chains and your mothers resistance training bands ;-)

References:

• Soria-Gila, Miguel A Nsca; Chirosa, Ignacio J Ph.D; Bautista, Iker J Ph.D; Chirosa, Luis J Ph.D; Salvador, Baena. Effects Of Variable Resistance Training On Maximal Strength: A Meta-Analysis. Journal Of Strength & Conditioning Research (2015): Ahead Of Print.
• Stastny, Petr; Lehnert, Michal; Zaatar Zaki, Amr Mohamed; Svoboda, Zdenek; Xaverova, Zuzana. Does The Dumbbell Carrying Position Change The Muscle Activity During Split Squats And Walking Lunges? Journal Of Strength & Conditioning Research (2015): Ahead Of Print.
• Wyland, Timothy P.; Van Dorin, Joshua D.; Cisco Reyes, G. F. Phd Cscs. 
• Post-Activation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats On Short Sprint Performance. Journal Of Strength & Conditioning Research (2015): Ahead Of Print.