Showing posts with label performance. Show all posts
Showing posts with label performance. Show all posts

Friday, March 18, 2016

8g day Citrulline Increase Leg Workout Performance More Reps on Leg Press Hack Squat Leg Ext in Exp Gymrats

The study tested only leg exercises, but you can safely expect increased reps on other exercises, as well.
Citrulline? Yes thats the stuff the supplement industry claims to be a better version of arginine. A "super pump supplement", but not necessarily an ergogenic - in spite of the fact that corresponding evidence from rodent and human studies (Briand. 1992; Pérez-Guisado. 2010; Giannesini. 2011) existed years before the study at hand was published (Wax. 2014).

Benjamin Wax and his colleagues from the Mississippi State University and the Auburn University  investigated the effects of citrulline malate supplementation on lower-body resistance exercise performance, blood lactate, heart rate, and blood pressure.

Based on citrulline malate’s chemical composition and a review of the current literature Wax et al. hypothesized that citrulline malate supplementation would mitigate fatigue occurring to the working muscle; therefore, augmenting resistance training performance.
You can learn more about citrulline at the SuppVersity

Citrulline prevents muscle catablism more than leucine

Arginine & citrulline for blood lipid control

EAA, BCAA, or citrulline for anti-catabolism?

Glutamine not citrulline to heal the gut?

Citrulline to ignite fatty acid oxidataion?

High & low dose arginine ineffec- tive NO boosters
To test their hypothesis the researchers recruited 12 advanced resistance trained male subjects (85kg body weight; <12% body fat; 22.1 ± 1.4 years) and conducted a randomized, counterbalanced, double blind study.

The subjects were randomly assigned to placebo or citrulline malate (8 g; 60 minutes before the workout) groups and then performed repeated bouts of multiple lower body resistance exercise:
"Subjects warmed up on an upright stationary bike (Life Fitness, Brunswick Corporation, Lake Fores, IL) for five minutes, at 60 – 70 revolution/minute with a mass of 3 – 5 kg. Following this warm up, subjects performed two warm up sets (10 repetitions at 90.9 kg and 8 repetitions at 136.4 kg) on the leg press machine. Subjects rested three minutes between sets during the warm up and trial sets.

Next, 60% of each subject’s predetermined 1RM was loaded on the leg press machine and the subject completed as many repetitions as possible until failure occurred. This process was completed for 4 additional sets for a total of 5 sets on the leg press. Next, the subjects performed one warm upset (10 repetitions) on the hack squat machine at a mass of 40.9 kg. This warm up set was followed by 5 sets of 60% of their predetermined 1RM to failure. Finally, following one warm up set (10 repetitions at 36.4 kg) on the leg extension, subjects completed 5 sets of 60% of their 1RM to failure." (Wax. 2014)
The rest periods (recovery periods between sets of exercise), exercise order, and number of sets performed were the same for all subjects in this investigation, for sessions 2 and 3. Blood lactate, heart rate, systolic blood pressure, and diastolic blood pressure were determined pre and post exercise.
Practical applications - What the scientists say: "Although citrulline malate supplements are marketed to improve muscle performance via a reduction in lactic acid and ammonia production, the current study does not fully support this assertion. While our investigation did note improved muscle performance occurring during the strength protocol,blood lactate remained indifferent comparing the citrulline malate treatment to the placebo treatment. The known capacity of citrulline malate to increase plasma L-arginine (Hickner. 2006), act as a buffer to lactate and hyperammonemia (Briand. 1992; Giannesini. 2011; Verleye. 1995) remain valid; however, further research is necessary to determine which mechanism may be directly attributed ergogenic effects occurring during resistance training protocols. Finally, specific investigations utilizing training protocols designed to test muscular strength and power are warranted." (Wax. 2014)
The exercise protocol resulted in sequential significant (p < 0.05) decrease in the number of repetitions in all three exercises. However, subjects in the citrulline malate group performed significantly (p < 0.05) higher number of repetitions during all three exercises compared to placebo group.
Figure 1: Wax et al. observed significant increases in maximal leg press, hack squat, and leg extension (not shown) repetitions in response to the ingestion of 8g of citrulline malate 60min before exercise (Wax. 2014)
Blood lactate and heart rate, on the other hand, were significantly increased (p < 0.05) post-exercise in both groups with no significant inter-group differences between citrulline malate and placebo (p > 0.05).
Bottom line: I am not sure, if the study at hand is going to change anyones perspective on citrulline. The "pump" is after all (for whatever reason) still what appears to be most attractive to trainees. The fact that the increased number of reps could translate into increased strength and size gains over time, on the other hand, doesnt appear sexy enough to be marketed as the main benefit of citrulline.

Can citrulline prevent muscle loss, when youre dieting | learn more
Apropos "main effect", there I guess you will remember that citrulline will also affect protein synthesis, right? Ive written about these effects in August last year in my article "Citrulline = The Dieters Amino Acid? Citrulline Maintains Muscle Protein Synthesis & Strength Endurance During Caloric Deficits Better Than Leucine!?" (read more).

So, if you dont consider increased rep numbers sexy enough, you may feel that a reduced muscle breakdown on your next diet may be worth heading over to the bulk supplier of your choice and order a 1kg bag of citrulline malate for 100$ (will last 125 days) - no? Well, honestly, I am not sure if its worth that, either | What do you think?
References:
  • Briand, Joël, et al. "Use of a microbial model for the determination of drug effects on cell metabolism and energetics: Study of citrulline?malate." Biopharmaceutics & drug disposition 13.1 (1992): 1-22.
  • Hickner, Robert C., et al. "L-citrulline reduces time to exhaustion and insulin response to a graded exercise test." Medicine and science in sports and exercise 38.4 (2006): 660-666.
  • Giannesini, Benoît, et al. "Citrulline malate supplementation increases muscle efficiency in rat skeletal muscle." European journal of pharmacology 667.1 (2011): 100-104.
  • Pérez-Guisado, Joaquín, and Philip M. Jakeman. "Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness." The Journal of Strength & Conditioning Research 24.5 (2010): 1215-1222.
  • Verleye, M., et al. "Effects of citrulline malate on bacterial lipopolysaccharide induced endotoxemia in rats." Arzneimittelforschung 45.6 (1995): E712.
  • Wax, Benjamin, et al. "Effects of Supplemental Citrulline Malate Ingestion During Repeated Bouts of Lower-body Exercise in Advanced Weight Lifters." The Journal of Strength & Conditioning Research (2014).


Read more »

Wednesday, March 16, 2016

Cut the Volume Still Make Gains! Performance Gains in Sprinters Dont Suffer From Reduced Training Volume Plus Best Volume Frequency for Size Strength Gains

A personal trainer who knows what hes doing is that he will push you exactly so far as it is necessary to make maximal progress. Interestingly, even the best trainers will fail doing the same for themselves.
The more is better mentality thats so characteristic of our lives in the Western world of affluence is imho the most important obstacle trainees all around the world meet on their way to increased muscle strength, size and performance. Against that background its a pity that the results of a recent study from the School of Kinesiology and Health Studies at the Queen’s University relate to sprint training, only. So, after having a look at Jason G. E. Zelt, I will briefly take a look at similar evidence from the more popular field of "working out to look good naked" and to be as strong as Superman.

But lets not waste any more time and sprint straight to the point! Zelt et al. published the results of the initially mentioned study in the peer-reviewed European Journal of Applied Physiology (Zelt. 2014).
Learn more about building muscle at www.suppversity.com

Optimizing Rest for Size and Strength Gains

Alternating Squat & BP - Productive?

Farmers Walk or Squat? Is Strong- men T. For You?

Full ROM ? Full Gains - Form Counts!

Battle the Rope to Get Ripped & Strong

Up Your Squat by 25% With Sodium Bicarbonate
As Zelt et al. point out, the purpose of this study was twofold: (1) to confirm that reductions in SIT work-interval duration do not result in reduced adaptations in aerobic and anaerobic capacity, and (2) to examine the effects of reduced work interval duration on submaximal determinants of exercise performance, namely lactate threshold and critical power.

In accordance with previous studies where aerobic capacity and aerobic performance were measured (Burgomaster. 2008; Hazell. 2010), the scientists hypothesized that reducing SIT work interval duration would have no effect on training-induced increases in lactate threshold and critical power.
Figure 1: Effects of high (SIT30) and lower volume (SIT15) training on power output and lactate threshold (Zelt. 2014)
And indeed, it hadnt. While there was a significant main effectof training on VO2peak such that VO2peak was elevated post-training, no significant difference was observed in the improvements observed between groups (ET ~13 %, SIT 30–4 %, SIT 15–8 %; not shown in Figure 1).
"A significant main effect of training was observed such that lactate threshold and critical power were higher during post-testing across all groups (p  <  0.05). There was a main effect of training (p  <  0.05) on Wingate peak power with no differences observed between groups at post training."
As the researchers point out, these results clearly indicate that "reducing SIT work-interval duration from 30 to 15 s had no impact on training-induced increases in aerobic or anaerobic power, or on increases in lactate threshold (absolute) and critical power."
Practically speaking, the results of this study imply it does not matter if you decrease the total volume on your sprint by 50%; and its not unlikely that this goes for other sports that require explosive strength, as well.
The initially hinted at question that remains is yet: "Is this true for the more popular training goal of getting strong, ripped and buffed, as well?" The answer to this question is certainly not easy to answer, as it may easily depend on your training status, your exact goals and maybe even the body parts youre training. You dont get it? Well, I guess its best Ill provide you with a few examples:
  • Look at his legs, Ronnie Coleman must have done something right... and guess what, the study at hand suggests that part of it could have been his insane training volume.
    the legs of advanced trainees may need a little more hammering -- Maybe you remember this being the take-home message from a previous article, i.e. "Advanced Trainees Benefit from Increased Training Volume! Greater & Steadier Strength Gains with 8 Sets of Squats. Plus: Over 6 Weeks, 1 Set and 4 Sets Equally (In-)Effective." | read more
  • the classic single vs. three set debate is still not settled -- While Starky et al.s 1996 study is one of the studies that appears to tip the scale in favor of studies suggests that there is no significant different in the strength and muscle gains in response to increasing the number of sets on a given exercise from one to three sets. Unfortunately, Starky et al. as well as most of their successors picked untrained noobs to test their hypothesis. And we all know: Noobs grow from simply looking at a barbell, right?

    So what do other studies say? Studies that used subjects like you and me? People who have been training regularly for ten or more years? People like the fifty-one experienced (>3 years), trained junior lifters who were randomly assigned to low, medium and high volume resistance training in a 2005 study by Juan J. Gonzalez-Badillo et al.
    Figure 2: Number of repetitions per week and average intensity (AI) during the 10-week training period in the low-volume (LVG), moderate-volume (MVG), and high-volume (HVG) training groups (left); EEffect size for the snatch, clean & jerk, and squat performances. LVG low volume group; MVG medium volume group; HVG high volume group (Gonzalez-Badillo. 2005)
    As you can see in Figure 2 (right), there is a highly significant advantage of the medium vs. both the low and high volume group who trained at significantly lower, respectively higher volumes (see Figure 2, left) than the guys in the medium volume group for squats and clean & jerks. The snatch, on the other hand, probably because it is the most demanding exercise, technically speaking, benefited from a "little" more volume (~ 100 reps per week).
  • the lower the volume, the higher the frequency -- Furthermore, the overview in Table 1, which was originally published as part of a review of the determinants of strength training success by Tan (1999) shows that another volume-related parameter, i.e. the training frequency, figures, as well; with high(er) frequencies producing greater increases in strength gains.
    Table 1: Summary of studies looking into optimal training frequency (Tan. 1999)
    Up to five training sessions for the upper and up to four for the lower body are possible, but whether theyre in fact as productive as the studies Tan cites would suggest appears questionable and will certainly depend on the volume of the individual sessions.

    The fact that it seems as if the upper body would respond more favorably to increases in training frequency than the lower body would albeit stand in line with the previously cited beneficial effects of high(er) volume training on the legs.

    Figure 3: Generally speaking a 2007 review of the literature by Mathias Wernbom et al. supports the notion that legs (in this case the quadriceps) dont just gain the most strength, but also the most size with ~3 training sessions per week; with the one outlier (12x/week) being a low intensity Kaatsu study by Abe et al. (2005)
    Why? Well, the study by Robins et al. conducted in 2012 (learn more) used a high volume on training days, but a necessarily low training frequency (two session per week, A + B). As Tan points out, ...
    "[...a]nother point to note from Table 1 is that previously trained athletes are closer to their strength potential and may require higher frequencies compared with untrained athletes" (Tan. 1999)."
    A statement that takes us back to the simple, but significant assessment that we cannot expect to find a training volume thats perfect for everyone: Individualization is key!
As far as the design of specific routines is concerned the previously cited review by Wernborn et al. offers a neat overview of suggested training principles, most of you will be familiar with.
Table 2: Recommendations for dynamic external resistance training for hypertrophy (Wernborn. 2007)
If you take a look at the middle column, you will hopefully realize that the suggested progression from 1-2 sets to 3-6 sets is specified on a "per muscle group" basis. The three biceps exercise with three sets of 8-12 reps, each, are thus off the charts, already; and youd be better off doing three sets of barbell curls and nosebreakers to end up at your maximum of six sets per body part (in this case the "arms") to return to the gym two days later and hammer your arms with three sets of hammer curls and cable press-downs.
The false believe that more helps more is also at the heart of the not exclusively female athletes triad.
Bottom line: I guess we all tend to do way more than wed need to, to achieve optimal results. Against that background its good to be reminded from time to time that "less can be more", as long as we do it frequently and consistently.

As my elaborations have shown, the latter is true for both the athletic / performance oriented, as well as the physique related outcome of any form of training. In the "best case" youre just wasting your time, as the sprint trainers in the study by Zelt et al. In the worst case, on the other hand, you end up in the deep dark black hole I wrote about in the athlete triad series a couple of months ago - a hole from which you can only escape by accepting the negative consequences of detraining and resting for a couple of weeks before you can resume your training slowly.
References:
  • Abe, Takashi, Charles F. Kearns, and Yoshiaki Sato. "Muscle size and strength are increased following walk training with restricted venous blood flow from the leg muscle, Kaatsu-walk training." Journal of Applied Physiology 100.5 (2006): 1460-1466.
  • Robbins, Daniel W., Paul WM Marshall, and Megan McEwen. "The effect of training volume on lower-body strength." The Journal of Strength & Conditioning Research 26.1 (2012): 34-39.
  • Tan, Benedict. "Manipulating resistance training program variables to optimize maximum strength in men: a review." The Journal of Strength & Conditioning Research 13.3 (1999): 289-304.
  • Wernbom, Mathias, Jesper Augustsson, and Roland Thomeé. "The influence of frequency, intensity, volume and mode of strength training on whole muscle cross-sectional area in humans." Sports Medicine 37.3 (2007): 225-264.
  • Zelt, Jason GE, et al. "Reducing the volume of sprint interval training does not diminish maximal and submaximal performance gains in healthy men." European journal of applied physiology (2014): 1-10.


Read more »

Performance Enhancing Gut Microbes First Study to Show Having The Right Gut Bugs Doubles Exercise Endurance

Yogurt & Co are good for athletes. But is this due to the bacteria?
As a regular here at the SuppVersity, you are well aware of the far-reaching effects of having the "right" or "wrong" bacteria in your tummy. The claim that having the "right" bacterial make-up in the gut could have beneficial effects on your performance in the gym or on the track is something you should not believe too credulously. If we had a study to prove these benefits, things would be different, though - a study like the one a group of researchers from the National Taiwan Sport University are about to publish in the scientific bible of resistance training, the Journal of Strength and Conditioning Research (Hsu. 2014).

In said study which is still available only as an accepted manuscript, Hsu et al. investigated the association of intestinal bacteria and exercise performance in specific pathogen-free (SPF), germ-free (GF), and Bacteroides fragilis (BF) gnotobiotic mice (animals in which only certain known strains of bacteria and other microorganisms are present).
You can learn more about the gut & your health at the SuppVersity

Bugs Dictate What You Crave

Sweeteners & Your Gut

Foods, Not Ma- cros for the Gut

Lactulose For Gut & Health

Probiotics Dont Cut Body Fat

The Macrobiotic MaPi2.0 Diet
To this ends, the scientist had the rodents swim to exhaustion to determine whether enteric bacteria alter antioxidant enzyme levels, exercise performance and physical fatigue. In addition, they tested the antioxidant enzyme activities, physical performance and anti-fatigue function after monocolonizing GF mice with B. fragilis (BF).
Figure 1: Time to exhaustion during exercise test and body composition of the miceaccording to the make-up of their gut microbiome; data expressed relative to group means (Hsu. 2014)
What they found was an increased time to exhaustion for the previously germ-free (GF) mice after theyd been colonized with B. fragilis (BF). Similar results were observed for the specific pathogen-free and Bacteroides fragilis gnotobiotic mice, who were also more enduring than the obesity resistant (Bäckhed. 2007) germ-free mice.
Do we have human data, as well? No, we dont have human data thats comparable to the one presented in the study at hand, but we do have evidence of beneficial (ergogenic) effects of probiotics and prebiotics in human "athletes". Examples? Well, the oral administration of the probiotic Lactobacillus fermentum VRI-003 and mucosal immunity in endurance athletes (Cox. 2010). Improved oxidative status in athletes during intense exercise training (Martarelli. 2011). Reduced risk of infection (Gleeson. 2011; West. 2011). And if thats not enough, what about keeping on top of your game by preventing and managing travellers’ diarrhoea (Tillett. 2006)!
As any SuppVersity veteran would expect, the germ-free mice were leaner than the rest of the pack. At the same time, the "sterile" mice did yet also have a lower liver, muscle, brown adipose, and epididymal fat pad weight than the SPF and BF mice.
Figure 2: Selected markers of antioxidant status in serum and liver; expr. rel. to group means (Hsu. 2014)
The markers of antioxidant defenses, the scientists measured were highest in the lean + light germ-free mice and their specific pathogen-free cousins. Against that background its at least somewhat surprising that the performance differences are pretty significant.
Pre- instead of probiotics: Personally, I believe that prebiotics, i.e. substances that promote the growth of the "right" bacteria are more promising agents than probiotics ("live" bacteria). Studies have shown that prebiotic at dosages above 2.5 g, which is far higher than that occurring in natural foods, increases the abundance of lactic acid and butyrate-producing bacteria. In that, galacto-oligo- saccharides (GOS) and  fructo-oligo- saccharides (FOS), are the prebiotics with the most positive outcomes.
As West points out in a 2012 mini-review as part of the BJSM "A–Z of nutritional supplements" series, the "potential benefits of supplementation with prebiotics on athletic performance are most likely indirect: they may be associated with the maintenance of gut health and perhaps a reduced risk of some illnesses which might enhance the athlete’s ability to train and compete." (West in DiMarco. 2012). Altering GI microbiota through the use of prebiotics may yet also favourably influence host metabolism. Athletes who are dieting, for example, will benefit from the reduction in appetite increase in gut peptide concentration in response to thec consumption of 16 g per day of FOS (Cani. 2009).
So what are the practical implications, then? As the authors emphasize, "[t]his is the first study to show that the intestinal microflora plays an important role in exercise performance." The way the microbial make-up regulates the antioxidant enzyme defense system is yet not in line with the observed reduction in physical fatigue Hsu et al. observed in the study at hand.

In view of the fact that the general assumption is that " intensive and sustained exercise training and high-level competition generate large amounts of free radicals that likely exceed the buffering capacity of the biological system, leaving athletes susceptible to oxidative stress", you would expect the Bacteriodes fragilis mice to perform the worst.

On the other hand, the mice harboring Bacteroides fragilis are significantly more muscular than the lightweight germfree mice... well, we could continue this discussion forever, but eventually the one result that may have a practical implication is the increased performance after mono-colonization in the germ-free mice. If nothing else, this result which happens to be the first evidence of performance enhancing effects of having a gut microbiome, would imply that you better recolonize your gut as soon as possible after a course of antibiotics. How the various different microbial status might regulate performance, on the other hand, will have to be elucidated in future studies - human (!) studies, that is | Comment on Facebook!
References:
  • Bäckhed, Fredrik, et al. "Mechanisms underlying the resistance to diet-induced obesity in germ-free mice." Proceedings of the National Academy of Sciences 104.3 (2007): 979-984.
  • Cani, Patrice D., et al. "Gut microbiota fermentation of prebiotics increases satietogenic and incretin gut peptide production with consequences for appetite sensation and glucose response after a meal." The American journal of clinical nutrition 90.5 (2009): 1236-1243.
  • Cox, Amanda J., et al. "Oral administration of the probiotic Lactobacillus fermentum VRI-003 and mucosal immunity in endurance athletes." British Journal of Sports Medicine 44.4 (2010): 222-226. 
  • DiMarco, N. M., et al. "A–Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance—Part 30." British journal of sports medicine 46.4 (2012): 299-300.
  • Gleeson, Michael, et al. "Daily probiotics (Lactobacillus casei Shirota) reduction of infection incidence in athletes." (2011). 
  • Hsu et al. "Effect of Intestinal Microbiota on Exercise Performance in Mice." Journal of Strength and Conditioning Research.  DOI: 10.1519/JSC.0000000000000644 | Publish Ahead of Print.
  • Martarelli, Daniele, et al. "Effect of a probiotic intake on oxidant and antioxidant parameters in plasma of athletes during intense exercise training." Current microbiology 62.6 (2011): 1689-1696.
  • West, Nicholas P., et al. "Lactobacillus fermentum (PCC®) supplementation and gastrointestinal and respiratory-tract illness symptoms: a randomised control trial in athletes." Nutrition journal 10.1 (2011): 30.


Read more »

Monday, February 29, 2016

First Human Study to Confirm That Repleting Low Vitamin C Levels W 1g Vitamin C Boosts Aerobic Performance

The study at hand used plain ascorbic acid, no quack supplements with "advanced vitamin C".
While people tend to believe that vitamin C is good for anything, the evidence that it actually does anything good is relatively scarce. Against that background I am happy to tell you that a group of Greek researchers from the School of Physical Education and Sport Science, the European University Cyprus and theAristotle University of Thessaloniki have now finally confirmed what many of you probably thought was a long-established fact: "[L]ow vitamin C concentration is linked with decreased physical performance and increased oxidative stress and that vitamin C supplementation decreases oxidative stress and might increase exercise performance only in those with low initial concentration of vitamin C." (Paschalis. 2014)
Learn more about hormesis and potential neg. effects of antioxidants at the SuppVersity

Is Vitamin E Good for the Sedentary Slob, Only?

NAC Impairs Anabolic Effects of Exercise

Vitamin C + E Hamper Gains in the Elderly

C+E Useless or Detrimental for Healthy People

Vitamin C and Glucose Management?

Antiox. & Health Benefits Dont Correlate
When they came up with the study design, Paschalis et al. simply assumed that the mythical ergogenic effect of vitamin C actually existed. To test this hypothesis, they screened 100 males for vitamin C baseline values in blood, picked the 10 individuals with the lowest and the 10 with the highest vitamin C values from their baseline sample and assigned them to two groups.
Figure 1: Overview of the study design (Paschalis. 2014)
Using a placebo-controlled crossover design, the 20 selected subjects performed aerobic exercise to exhaustion (oxidant stimulus) before and after vitamin C supplementation for 30 days.
An overview of the study design is shown in Fig. 1. All measurements were performed between 08:00 and 11:00 h after overnight fasting. Initially, to examine whether rest ing blood vitamin C concentration affects aerobic perfor mance, VO2max was assessed (using incremental cycling test to volitional exhaustion) and was compared in both the low and the high vitamin C groups (Monark, Vansbro, Swe den). More specifially, the protocol started with a 50 W load at 50 rpm and increased by 10 W every 2 min until volitional fatigue. The test was terminated when three of the following four criteria VO2max were met: (1) volitional fatigue, (2) a lower than 2 mL/kg/min increase in VO2 despite an increase in workload, (3) a respiratory exchange ratio greater than or equal to 1.10, and (4) heart rate within 10 bpm of the predicted maximal heart rate (220–age). Res piratory gas variables were measured using a metabolic cart (Quark b2, Cosmed, Italy), which was calibrated before each test using standard gases of known concentration. The VO 2max assessment was used as a reference value to cal culate the workload at the relative intensity of each subject and ensured that all subjects would cycle at similar relative intensity during the following aerobic exercise sessions.
After the baseline testing had been done, the subjects within both the low and the high vitamin C groups received either placebo (3x333mg of lactose) or vitamin C supplementation (3x333mg of vitamin C), in a double-blind randomized crossover fashion (see Figure 1).
Figure 2: Changes in VO2max (left) and redox status (right) in subjects according to initial vitamin C status before and after vitamin C supplementation for 30 days (Paschalis. 2014).
As you can see in Figure 2 there were measurable differences in the response to the acute exhaustive exercise protocol (an oxidant stimulus), the subjects in both groups performed before and after vitamin C or placebo supplementation for 30 days. The data in Figure 2 does yet also show that the subjects who had been randomly assigned to the vitamin C supplement group had lower baseline VO2max levels. A fact that raises the question whether this is the result of a lower vitamin C intake or whether the vitamin C intake correlates with an unhealthier lifestyle that left the subjects unfit and with low vitamin C levels.
Illustration of the relationship between radicals and antioxidants in the determination of redox balance. An increase in radicals or antioxidants results in a disturbance in redox balance (Powers. 2004).
So what, to supplement with antioxidants or not? I have voiced my opinion often enough and still people ask me time and again whether it "may not be a good idea to..." Against that background I will not repeat myself, but quote someone else, Scott K. Powers and Kurt J. Sollanek who wrote an extensive review of the literature for one of the latest issue of the Sports Science Exchange: "Exercise promotes radical production in the working muscles and prolonged/intense exercise can produce an imbalance between radical production and muscle antioxidants altering the “redox balance” and resulting in oxidative stress. To protect against radical mediated damage, muscle cells contain endogenous antioxidants to scavenge radicals.

Moreover, exogenous antioxidants obtained in the diet cooperate with endogenous antioxidants to form a supportive network of cellular protection against radical-mediated oxidative stress. In regard to exogenous antioxidants, a varied diet of fruits and vegetables is a sensible means of obtaining a balance of exogenous antioxidants. In contrast, because of the risk of negative consequences, consuming megadoses of antioxidants via supplements is not recommended" (Powers. 2014 | my emphases).
Unfortunately, this question is hard to answer based on the available research on vitamin C. While we have conflicting results with respect to its ability to impair the adaptational response to exercise (Close. 2014), there is very little evidence that it will actually have beneficial effects on any meaningful performance parameters. In fact, a study by Huck et al. that was published in the scientific journal Nutrition in 2013 is probably what comes closest to the results of the study at hand.
Figure 3: Effects of 500mg vitamin C per day on selected parameters in a 4 week chronic exercise + diet supplementation in obese men and women (Huck. 2013)
In said study Huck et al. observed that the provision of 500mg of vitamin C as an adjunct to exercise and diet in obese individuals lead to significant reductions in heart rate and the ratings of perceived exertion during exercise. The data in in Figure 3 does yet also tell you that there were no beneficial effects on VO2max, which best reflects the adaptational response to exercise.

This results of stands in contrast to the study at hand, but in line with previous results of studies in athletes, where only more or less irrelevant reductions of the acute inflammatory response to exercise were observed (Nieman. 2000; Peters. 2001; Tauler. 2002). A response of which you as a SuppVersity reader know that it is an essential part of the signalling cascade that triggers the adaptational response to. If we eventually get back to the Paschalis study, it would thus appear that athletes who are usually consuming more than enough vitamin C in their diets and are not at particular risk of developing low serum vitamin C levels would see similar results as the "high vitamin C" subjects in the Paschalis study, i.e. none - even worse, in view of the potential negative effects on the training induced adaptations that could not become visible in the study at hand, because there was no exercise protocol involved, it could even harm their progress.
Bottom line: Just like the researchers had expected, they found higher resting levels of oxidative stress and decreased exercise performance in the individuals with low baseline values of vitamin C compared to those with high vitamin C values.

Figure 3: Rel. changes in PGC-1? in cytosolfractions in the vitamin C and E group and the placebo group of a randomized controlled antioxidant + exercise study by Paulsen et al. (2014) - find out what boosts PGC-1? | here.
Since the provision of 1g of vitamin C oxidative stress, it is thus not surprising that there was a concomitant increase in exercise performance. What is "surprising", though, is that the latter was "marginally" and clearly "non-signifiant." Furthermore, it was observed only in those individuals with a poor initial vitamin C status. In that, it is a novel finding that you do not need to suffer from hypovitaminosis C  (<23µmol/L) or vitamin C deficiency to be derive acute benefit from vitamin C supplementation as regards to redox status and physical performance. Previous studies which combined the provision if vitamin C with chronic exercise training, however, indicate that the ingestion of anti-oxidants can blunt the intra-cellular adaptive responses to exercise (Paulsen. 2014) - an effect that obviously couldnt be confirmed or negated in the study at hand, because it lacks a chronic exercise component | Comment on Facebook!
References:
  • Close, G. L., and M. J. Jackson. "Antioxidants and exercise: a tale of the complexities of relating signalling processes to physiological function?." The Journal of physiology 592.8 (2014): 1721-1722.
  • Huck, Corey J., et al. "Vitamin C status and perception of effort during exercise in obese adults adhering to a calorie-reduced diet." Nutrition 29.1 (2013): 42-45.
  • Nieman, David C., et al. "Influence of vitamin C supplementation on cytokine changes following an ultramarathon." Journal of Interferon & Cytokine Research 20.11 (2000): 1029-1035.
  • Paschilis, V. et al. "Low vitamin C values are linked with decreased physical performance and increased oxidative stress: reversal by vitamin C supplementation." Eur J Nutr (2014). Ahead of print.
  • Paulsen, Gøran, et al. "Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double?blind, randomised, controlled trial." The Journal of physiology 592.8 (2014): 1887-1901.
  • Peters, E. M., et al. "Vitamin C supplementation attenuates the increases in circulating cortisol, adrenaline and anti-inflammatory polypeptides following ultramarathon running." International journal of sports medicine 22.7 (2001): 537-543.
  • Picklo, Matthew. "Supplementation with vitamin E and vitamin C inversely alters mitochondrial copy number and mitochondrial protein in obese, exercising rats (1030.5)." The FASEB Journal 28.1 Supplement (2014): 1030-5. 
  • Powers, Scott K., et al. "Dietary antioxidants and exercise." Journal of sports sciences 22.1 (2004): 81-94.
  • Powers, Scott K., And Kurt J. Sollanek. "Endurance Exercise And Antioxidant Supplementation: Sense Or Nonsense?-Part." Sports Science 27.137 (2014): 1-4.
  • Tauler, P., et al. "Diet supplementation with vitamin E, vitamin C and ?-carotene cocktail enhances basal neutrophil antioxidant enzymes in athletes." Pflügers Archiv 443.5-6 (2002): 791-797.


Read more »