*Vitamin C Decreases Training Efficiency

[SupremeSportsEnhance]

Discuss:

**broken link removed**

American Journal of Clinical Nutrition, Vol. 87, No. 1, 142-149, January 2008

© 2008 American Society for Nutrition

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ORIGINAL RESEARCH COMMUNICATION

Oral administration of vitamin C decreases muscle mitochondrial biogenesis and hampers training-induced adaptations in endurance performance1,2,3
Mari-Carmen Gomez-Cabrera, Elena Domenech, Marco Romagnoli, Alessandro Arduini, Consuelo Borras, Federico V Pallardo, Juan Sastre and Jose Viña
1 From the Department of Physiology, Faculty of Medicine, University of Valencia, Valencia, Spain (M-CG-C, ED, AA, FVP, JS, and JV); the Catholic University of Valencia, Valencia, Spain (CB); and the Polytechnic University of Valencia, Valencia, Spain (MR)


Background: Exercise practitioners often take vitamin C supplements because intense muscular contractile activity can result in oxidative stress, as indicated by altered muscle and blood glutathione concentrations and increases in protein, DNA, and lipid peroxidation. There is, however, considerable debate regarding the beneficial health effects of vitamin C supplementation.

Objective: This study was designed to study the effect of vitamin C on training efficiency in rats and in humans.

Design: The human study was double-blind and randomized. Fourteen men (27–36 y old) were trained for 8 wk. Five of the men were supplemented daily with an oral dose of 1 g vitamin C. In the animal study, 24 male Wistar rats were exercised under 2 different protocols for 3 and 6 wk. Twelve of the rats were treated with a daily dose of vitamin C (0.24 mg/cm2 body surface area).

Results: The administration of vitamin C significantly (P = 0.014) hampered endurance capacity. The adverse effects of vitamin C may result from its capacity to reduce the exercise-induced expression of key transcription factors involved in mitochondrial biogenesis. These factors are peroxisome proliferator–activated receptor co-activator 1, nuclear respiratory factor 1, and mitochondrial transcription factor A. Vitamin C also prevented the exercise-induced expression of cytochrome C (a marker of mitochondrial content) and of the antioxidant enzymes superoxide dismutase and glutathione peroxidase.

Conclusion: Vitamin C supplementation decreases training efficiency because it prevents some cellular adaptations to exercise.

 

[J.Blaze]

I know it was a study, but some may disagree. Phil Hernon suggests using Vitamin C and he definitely knows his shit. His word is gospel when it comes to training and supplements.

 

[SupremeSportsEnhance]

I know it was a study, but some may disagree. Phil Hernon suggests using Vitamin C and he definitely knows his shit. His word is gospel when it comes to training and supplements.

Yes, I agree that Vitamin C has numerous beneficial effects in the human body, and I too supplement with Vitmain C daily(2,000-3,000mg).

I was surprised to find this data, which is why I am eager to generate some discourse...

 

[Swifto]

The study size is tiny.

I'm not a marathon runner either.

Vitamin C lowers cortisol post workout, studies confirm it. Who gives a shit if it effects endurance slightly.

I'm just reading the full paper.

 

[Swifto]

Ok.

Its on "sedentary" individuals.

Study size is tweeney weeney.

To quote from the full paper, "In the human study, we found an almost-identical result: VO2max increases of 22.0% in the unsupplemented group of men
and 10.8% in the supplemented group after 8 wk of training.
These differences were not significant, but there were data from
only 5 men, and thus the study may not have been adequately
powered to find a difference."

It cut the increase in VO2max by 1/2. A fair amount, but its on "5 subjects".


What a watse of time.

Ross why dont you read the full paper before you post this garbage?

 

[SupremeSportsEnhance]

The study size is tiny.

I'm not a marathon runner either.

Vitamin C lowers cortisol post workout, studies confirm it. Who gives a shit if it effects endurance slightly.

Do you have the full paper?

While Vitamin C does exert a small anti-catabolic effect, this may be offset by decreasing mitochondria in muscle cells, which is definitely a bad trade-off. Mitochondria in cells are what convert what we eat into energy the muscles can use, which is why they are known as “the powerhouse of the cell”. Less Mitochondria, less strength, endurance, and recovery.

Especially while using Anabolic Androgenic Steroids, it's not worth the small decrease in cortisol. Vitamin C reduces the exercise-induced expression of key transcription factors involved in mitochondrial biogenesis. Vitamin C also prevented the exercise-induced expression of cytochrome C (a marker of mitochondrial content) and of the antioxidant enzymes superoxide dismutase and glutathione peroxidase.

I'm not saying to abondon Vitamin C altogether, I am however suggesting to lower your dosage if you are consuming upwards of 3grams daily.

 

[Swifto]

While Vitamin C does exert a small anti-catabolic effect, this may be offset by decreasing mitochondria in muscle cells, which is definitely a bad trade-off. Mitochondria in cells are what convert what we eat into energy the muscles can use, which is why they are known as “the powerhouse of the cell”. Less Mitochondria, less strength, endurance, and recovery.


Especially while using Anabolic Androgenic Steroids, it's not worth the small decrease in cortisol. Vitamin C reduces the exercise-induced expression of key transcription factors involved in mitochondrial biogenesis. Vitamin C also prevented the exercise-induced expression of cytochrome C (a marker of mitochondrial content) and of the antioxidant enzymes superoxide dismutase and glutathione peroxidase.

I'm not saying to abondon Vitamin C altogether, I am however suggesting to lower your dosage if you are consuming upwards of 3grams daily.

Nice copy and paste Ross. You should quote correctly in "" and italics. But you want to come off intelligent dont you mate?

Again, your basing your opinoin on a study done on "5 subjects", which is pretty stupid on your part. You may have a point if this was on 500 subjects, but its not. I've also already stated it was on untrained individuals.

The author's of the study even confirm it pretty much means nothing. The study is based on rodents mainly.

Yet you seem to think you have a point of lowering Vitamin C intake because of it. I honestly thought you were a little more logical than that, but you never fail to entertain me.

But you lower your intake if you feel the need. The study was also done over "40minutes" at a rate of "65-80% VO2max".

 

[Ash2021]

I'm still going to take my C.

 

[Elvia1023]

You can find a study saying almost anything these days. Many of the 'good' things we take usually carry a few negatives. You will hear how one thing is amazing for years then you suddenly hear it causes cancer etc. I find the key is to just use common sense and use validated research sources.

Like the above states if it was conducted using 500 individuals who actively train then I would take note. I have read too many studies stating how good vit c is (numerous benefits). I have probably tried more supplements than most cause I manage a supplement shop and yeah most are simply unneeded. But vit c is defo up there in my list to take daily. I have about 3 I take all year round and vit c is one of them.

 

[SupremeSportsEnhance]

Nice copy and paste Ross. You should quote correctly in "" and italics. But you want to come off intelligent dont you mate?

Again, your basing your opinoin on a study done on "5 subjects", which is pretty stupid on your part. You may have a point if this was on 500 subjects, but its not. I've also already stated it was on untrained individuals.

The author's of the study even confirm it pretty much means nothing. The study is based on rodents mainly.

Yet you seem to think you have a point of lowering Vitamin C intake because of it. I honestly thought you were a little more logical than that, but you never fail to entertain me.

But you lower your intake if you feel the need. The study was also done over "40minutes" at a rate of "65-80% VO2max".

Swifto, I posted the study to generate a discussion, I never concluded that Vitamin C should be omitted completely from your supplement regimen. The study conducted was small indeed, but it still illuminates some important issues for BODYBUILDERS supplementing with Vitamin C. I would like to continue the discussion, I don't know why you are attacking me for posting an article.

 

[PHIL HERNON]

Well

Swifto, I posted the study to generate a discussion, I never concluded that Vitamin C should be omitted completely from your supplement regimen. The study conducted was small indeed, but it still illuminates some important issues for BODYBUILDERS supplementing with Vitamin C. I would like to continue the discussion, I don't know why you are attacking me for posting an article.

I applaud you Ross.....keep studies coming.....all angles should be examined.......but again, moderation/common sense apply most times.

 

[Nikopapp]

I have begun crushing 1,500mg of vitamin C and putting it in my water ( with LBA's) for drinking during my workouts.
I have noticed decreased DOMS and recovery between sets seems to be a little quicker.
I also take 1,00mg in the morning.
So I'll stay with my C.

 

[SupremeSportsEnhance]

I have begun crushing 1,500mg of vitamin C and putting it in my water ( with LBA's) for drinking during my workouts.
I have noticed decreased DOMS and recovery between sets seems to be a little quicker.
I also take 1,00mg in the morning.
So I'll stay with my C.

DOMS may be NECEASSARY for optimal hypertrophy and recovery. There are growth signals that result from muscle damage that are required for anabolism, and Vitamin C may impair those signals.

However, check out this study on the subject:


Vitamin C: post-exercise Vitamin C does not aid recovery from delayed-onset muscle soreness

Hopes that vitamin C supplementation after heavy exercise could aid recovery have been dashed by a recent British study, which found no beneficial effect on delayed-onset muscle soreness (DOMS).

Unaccustomed exercise causes muscle damage and a reduced ability to generate force. Although the initial damage is generally related to mechanical stress, it has been suggested that the extent of damage increases during the post-exercise period and that at least some of this is caused by ‘free radicals’ produced as a by-product of energy-production (oxidation).

Vitamin C is a known ‘antioxidant’ and it has been suggested that there may be an increased requirement of this vitamin after unaccustomed exercise in order to minimise muscle damage and so hasten recovery.

The 16 men recruited to the study performed 90 minutes of variable-intensity shuttle-running in a gym over 20m after being tested for muscle function and soreness. After the exercise period, all the subjects followed the same prescribed diet for three days, including 100mg of vitamin C daily. In addition, half the group consumed 200mg of supplementary vitamin C twice daily while the other half took a placebo (dummy) preparation. After three days the muscle function and soreness tests were repeated.

Although blood tests showed that vitamin C supplementation successfully increased vitamin C concentrations for the three days following exercise testing, there was no associated improvement in recovery, with muscle soreness and signs of inflammation the same in both groups. Muscle force – particularly in the leg flexors – was reduced below pre-exercise levels for up to three days in both groups, with no difference between the groups.

Plasma vitamin C levels in both groups were increased at the end of exercise, but further boosting these levels failed to improve recovery. There was no decline in vitamin C levels in either group in the days following exercise, suggesting that the dietary provision of 100mg daily was enough to keep the levels stable.

These results suggest that if muscle function is reduced as a result of increased post-exercise oxidative stress, supplementation with vitamin C is unable to reduce the extent of the damage. One possible explanation is that vitamin C consumed after exercise may not be delivered to the appropriate sites where its antioxidant properties could improve recovery.

Eur J Appl Physiol (2003) 89: 393-400

 

[SupremeSportsEnhance]

OK, this article of scientific data is very useful in determining the effectivess of Vitamin C for a plethora of different applications:

Vitamin C

According to numerous double-blind, placebo-controlled studies, regular use of vitamin C supplements can slightly reduce symptoms of colds and modestly shorten the length of the illness.17,18,146 However, taking vitamin C at the onset of a cold probably will not work.83,140

Regular use of vitamin C does not seem to help prevent colds.86,146 One exception is the “post-marathon sniffle”—colds that develop after heavy exercise.19,20 Vitamin C may be helpful for preventing this condition, although not all studies agree.153

Two double-blind studies suggest that the use of vitamin C combined with vitamin E might slightly reduce the risk of developing preeclampsia, a complication of pregnancy.21,169 However, a much larger follow-up study failed to find benefits.170

Two studies conducted by a single research group have found that vitamin C at a dose of 500 mg daily might help prevent reflex sympathetic dystrophy, a poorly understood condition that can follow injuries such as fractures.110,180

Over time, the body develops tolerance to drugs in the nitrate family (such as nitroglycerin). Some evidence suggests that use of vitamin C can help maintain the effectiveness of these medications.142-145

Other small double-blind trials suggest that vitamin C might be helpful for anterior uveitis (when taken in combination with vitamin E),52 autism,40 easy bruising,29 minor injuries,41 protecting the liver in nonalcoholic steatohepatitis,154 speeding recovery from bedsores,37 treating female infertility (specifically, a condition called "luteal phase defect"),155 and preventing early rupture of the chorioamniotic membranes ("the water breaking") in pregnancy.156 Vitamin C might also improve the effectiveness of antibiotic treatment for Helicobacter pylori, the cause of most peptic ulcers.179

Preliminary evidence suggests that cream containing vitamin C may improve the appearance of aging or sun-damaged skin.50,51,157 Inconsistent evidence suggests that oral or topical vitamin C, taken by itself or in combination with vitamin E, may also help protect the skin against sun damage.42-49

Double-blind studies of vitamin C for the following conditions have yielded mixed results: asthma,30, 178 male infertility,38,39 reducing the muscle soreness that typically develops after exercise,36,176,177 and hypertension.31-35,147,148 Note: Unexpectedly, one study found that a combination of vitamin C (500 mg daily) and grape seed oligomeric proanthocyanidins (OPCs) (1,000 mg daily) slightly increased blood pressure.158 Whether this was a fluke of statistics or a real combined effect remains unclear.

Limited and in some cases contradictory evidence suggests possible benefit in the prevention or treatment the following conditions:

Allergies56-58
Atrial fibrillation following coronary artery bypass grafting (CABG)182
Bladder infections during pregnancy181
Gallbladder disease (in women)53
General anesthetics 171
Glaucoma149
Gout172
Obesity173-175
Vascular dementia54

Intravaginal use of vitamin C tablets might be helpful for non-specific vaginitis.159

Observational studies indicate that people with a higher intake of vitamin C have a lower incidence of cataracts, macular degeneration, heart disease, cancer, and osteoarthritis.22-27,59-66 However, these findings do not indicate that vitamin C supplements will help prevent or treat these conditions. Observational studies are notoriously unreliable for showing the efficacy of treatments; only double-blind studies can do that, and only one has been performed that directly examined vitamin C’s potential benefits for preventing these conditions. (For more information on why double-blind studies are so important, see Why Does This Database Rely on Double-blind Studies? ) Two large double-blind trials exploring the effectiveness of vitamin C for heart disease prevention—one in women at high risk181 and the other in men at low risk— 183 failed to find any benefit at all.

Vitamin C has been proposed as a treatment for cancer, but this claim is very controversial, and there is as yet no scientifically meaningful evidence that it works.67-70

Massive doses of vitamin C have at times been popular among people with HIV infection based on highly preliminary evidence.71,72 An observational study linked high doses of vitamin C with slower progression to AIDS.73 However, a double-blind study of 49 people with HIV who took combined vitamins C and E or placebo for 3 months did not show any significant effects on the amount of HIV detected or the number of opportunistic infections.74 Furthermore, one study found that vitamin C at a dose of 1 g daily substantially reduced blood levels of the drug indinavir, a protease inhibitor used for the treatment of HIV infection.160 This could potentially cause the drug to fail.

One substantial study failed to find vitamin C useful for improving high cholesterol.161

According to a double-blind, placebo-controlled study of 141 women with cervical dysplasia (early cervical cancer), vitamin C, taken at a dosage of 500 mg daily, does not help to reverse the dysplasia.75

Vitamin C also does not appear to be helpful for treating Raynaud’s phenomenon caused by scleroderma.150

 

[SupremeSportsEnhance]

More great info:


Effects of Exercise on Vitamin C Requirements

The evidence addressing the vitamin C requirement of athletes is abundant and contradictory. Multiple studies have found blood and plasma levels of vitamin C to be diminished in those who exercise. Keith (24) summarizes the findings of Namyslowski who published two papers addressing the requirement of ascorbate in exercising individuals. The second study concluded that blood vitamin C levels decreased in athletes ingesting 100 mg per day. A dietary intake of 300 mg/day maintained blood levels of the vitamin. This was some of the first evidence to suggest vitamin C needs are increased in those who exercise. Athletes receiving a one-gram vitamin C supplement showed increased work capacity at a heart rate of 170 beats per minute. Subjects served as self-controls and were given a placebo for two weeks and then vitamin C for two weeks. During vitamin C supplementation subjects repeatedly demonstrated decreased heart rates at all levels of work when compared with the placebo trial (16). However, treatments (placebo or vitamin) were given in succession. An alternate study by Telford et al. (35) provided evidence that supplementation for 7 to 8 months did not have any significant effect on blood levels of the vitamin. However, females were shown to have significantly higher levels of vitamin C in their blood versus the male population. Also, this study showed that plasma vitamin C levels could remain elevated for 24 hours after strenuous exercise (11,39). Vitamin C has shown favorable effects when used during heat acclimatization in humans. Two separate studies (26, 33) from the 1970s have both shown similar results. Plasma levels of ascorbic acid in thirteen male volunteers rose to a level fourfold higher in supplemented (250 mg or 500 mg) than unsupplemented subjects. The higher plasma levels of ascorbate were associated with reduced body temperature and sweat loss. These results support the hypothesis that vitamin C is beneficial to those trying to acclimatize themselves to heat (27). In a study done one year earlier the same results were found. However, it was determined that doses of 500 mg versus 250 mg result in no enhanced benefits in subjects acclimatizing to heat (33). The effects of vitamin C supplementation on anaerobic and aerobic work capacity were investigated by Keren and Epstein (26). Thirty-three healthy males partook in a 21-day training session that uses primarily involved mainly aerobic work. Measures of aerobic and anaerobic work capacity were then measured. Vitamin C supplementation provided no enhancement in either aerobic or anaerobic work. Many ultra long-distance runners experience upper respiratory tract infections. Peters et al. (30) addressed the possible role of vitamin C in preventing these infections. Symptoms of upper respiratory infection were monitored for 14 days after an ultramarathon (> 26.2 miles) in subjects receiving either placebo or vitamin C supplementation. Sixty-eight percent of the runners on the placebo reported the development of respiratory tract infections. In contrast only one-third of the vitamin C group reported the infections. The scientists concluded that vitamin C supplementation may actually be beneficial in helping prevent upper respiratory infections in ultramarathoners. Blood vitamin C levels greater than 0.6mg/100ml have been established as being adequate (41). Multiple studies have shown blood vitamin C levels of various athletes including runners (11,40) to be adequate. Concentrations of plasma AA have been reported to be significantly higher five minutes after a 21 km (13.1 mile) run than baseline values. The levels then fell 20% below pre-exercise values within 24 hours and remained depressed for 2 days (11). This may be due to a loss in plasma volume following exercise. Contradictory results were found by Rokitzki et al. (31) and Glesson et al. (11) who found that vitamin C was higher immediately after exercise. However, Rokitzki et al. (31) also noted that the levels remained high for 24 hours following a marathon. The fluctuating levels of vitamin C are likely controlled by the adrenal gland (11). In conclusion, a high probability exists that a large majority of athletes consume sufficient vitamin C in their diet. At the same time it is know that a diet lacking vitamin C will in turn inhibit performance (5). A daily intake between 100-300 mg of vitamin C may be warranted to meet the needs of all people who exercise (5). However, until an alternative RDI for athletes is established the recommended intake for vitamin C shall remain at 75 mg for women and 90 mg for men. Doses of 1500 milligrams or greater oversaturate the body pool and are excreted in the urine. Therefore, multiple large doses are not warranted. One must also be aware of the enzyme kinetics of vitamin C transport. Multiple small doses help prevent side effects and are advised for those choosing to consume large quantities or supplement with the vitamin. The previously mentioned levels are easily obtainable by substituting a well-balanced diet for a supplement. Clarkson summarizes (7) that athletes taking a multivitamin do not appear to obtain ergogenic benefits and likely do not need the supplementation (40). However, a small portion of those who exercise will lack an adequate vitamin C intake. Bazzarre et al. (3) have shown some bodybuilders have vitamin C intakes below 40 mg. Similar conclusions were found in basketball players (15), cyclists (25), and even Navy Seals (8). Currently it appears that the variety and adequacy of individual diets will determine if supplementation with vitamin C is needed.

Vitamin C And Exercise Recovery

Current research concerning vitamin C and exercise recovery is limited at best. A previously mentioned study found that vitamin C supplementation prevented muscle soreness (21). However, the aim of the study was not that of exercise recovery, but rather peroxidation of membranes. Vasankari et al. (39) performed one of the few studies addressing the role of vitamin C in exercise recovery. Conjugated dienes decreased by 11% after exercise in those individuals who ingested vitamin C versus those receiving a placebo. The design of this study should be noted as the subjects received one gram of vitamin C in supplement form immediately after a bout of exercise. However, these methods and results may be the basis for future research addressing vitamin C (and antioxidant) supplementation immediately after exercise. This author believes that vitamin C likely only aids in recovery if a person is deficient in the vitamin. The adrenal gland has been shown to regulate vitamin C release into the plasma (11). The significance of this has yet to be determined. However, it is likely that vitamin C does not directly function in muscle recovery because post-exercise values in the previous study (11) fell to values 20% below baseline within the first 24 hours of recovery. The possibility does exist that vitamin C may play an indirect role in exercise recovery. The vitamin has the ability to regenerate vitamin E. This means that any function vitamin E has within the body can also be linked back to vitamin C. The literature suggests that the role vitamin E plays in muscle recovery is limited and contradictory at this time. The relationship between vitamin E and muscle recovery is further addressed in a separate section. In summary, the role of vitamin C in exercise recovery is not known. The literature to date seems to imply that vitamin C probably has no direct significant role in muscle recovery from exercise, but may possibly play a significant indirect role in the process.

 

[Elvia1023]

I applaud you Ross.....keep studies coming.....all angles should be examined.......but again, moderation/common sense apply most times.

Agreed. Without studies we wouldn't learn. In 20 years time we will know so much more because of studies and advancements. But like I said above I am still gonna take my vit c. The most I take a day is 2.8g. But it's usually 2.1g. In a rush now and just scanned over the last study. Sounds interesting but again not enough people. But if a study shows something up with 20 people then it should with 200 or 2000. And the dose used was only 200mg... most use much more than that pwo or any other time. Anyway for a day now but look forward to seeing how this thread goes.

My pwo mix is usually vit c, lycopene, aminos and milk thistle. I swop the anti-oxidants over time. Cherry and acai with green tea are the others I will exchange over time.

 

[Elvia1023]

Just noticed the others. Will read them on my return. Good work

 

[SupremeSportsEnhance]

Post-exercise vitamin C supplementation and recovery from demanding exercise

Journal European Journal of Applied Physiology
Publisher Springer Berlin / Heidelberg
ISSN 1439-6319 (Print) 1439-6327 (Online)
Issue Volume 89, Numbers 3-4 / May, 2003
Category Original Article
DOI 10.1007/s00421-003-0816-4
Pages 393-400
Subject Collection Biomedical and Life Sciences
SpringerLink Date Thursday, May 01, 2003
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Original Article
Post-exercise vitamin C supplementation and recovery from demanding exercise
D. Thompson1 , C. Williams2, P. Garcia-Roves2, S. J. McGregor2, F. McArdle3 and M. J. Jackson3

(1) Department of Sport and Exercise Science, University of Bath, BA2 7AY, Bath, UK,
(2) Human Muscle Metabolism Research Group, Loughborough University, LE11 3TU, Loughborough, UK,
(3) Muscle Research Centre, Department of Medicine, University of Liverpool, L69 3BX, Liverpool, UK,

Accepted: 10 February 2003


The aim of this study was to investigate whether post-exercise vitamin C supplementation influences recovery from an unaccustomed bout of exercise. Sixteen male subjects were allocated to either a placebo (P; n=8) or vitamin C (VC) group (n=8). Subjects performed a prolonged (90-min) intermittent shuttle-running test, and supplementation began after the cessation of exercise. Immediately after exercise the VC group consumed 200 mg of VC dissolved in a 500 ml drink, whereas the subjects in the P group consumed the drink alone. Later on the same day and then in the morning and evening of the following 2 days, subjects consumed additional identical drinks. Plasma VC concentrations in the VC group increased above those in the P group 1 h after exercise and remained above P values for the 3 days after exercise. Nevertheless, post-exercise VC supplementation was not associated with improved recovery. Post-exercise serum creatine kinase activities and myoglobin concentrations were unaffected by supplementation. Muscle soreness and the recovery of muscle function in the leg flexors and extensors were not different in VC and P groups. Furthermore, although plasma concentrations of interleukin-6 and malondialdehyde increased following exercise, there was no difference between VC and P groups. These results suggest that either free radicals are not involved in delaying the recovery process following a bout of unaccustomed exercise, or that the consumption of VC wholly after exercise is unable to deliver this antioxidant to the appropriate sites with sufficient expediency to improve recovery.

 

[SupremeSportsEnhance]

Prolonged vitamin C supplementation and recovery from eccentric exercise
Journal European Journal of Applied Physiology

Publisher Springer Berlin / Heidelberg
ISSN 1439-6319 (Print) 1439-6327 (Online)
Issue Volume 92, Numbers 1-2 / June, 2004
Category Original Article
DOI 10.1007/s00421-004-1064-y
Pages 133-138
Subject Collection Biomedical and Life Sciences
SpringerLink Date Saturday, March 13, 2004
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Original Article
Prolonged vitamin C supplementation and recovery from eccentric exercise
D. Thompson1 , D. M. Bailey2, J. Hill2, T. Hurst3, J. R. Powell3 and C. Williams2

(1) Department of Sport and Exercise Science, University of Bath, Bath , BA2 7AY, UK
(2) Human Muscle Metabolism Research Group, Loughborough University, Loughborough , LE11 3TU, UK
(3) Colworth Laboratory, Unilever Research, Bedford , MK441LQ, UK

Accepted: 21 January 2004 Published online: 13 March 2004

Abstract We have previously shown that vitamin C supplementation affects recovery from an unaccustomed bout of demanding exercise, with the most pronounced effect being that on plasma interleukin-6 concentration. However, because of the proposed role of interleukin-6 in the regulation of metabolism, it was unclear whether this represented a reduced response to muscle damage or some form of interaction with the metabolic demands of the activity. Therefore, the aim of the present study was to investigate the effect of the same form of supplementation on a bout of exercise that initiated similar muscle damage but had a low metabolic cost. Fourteen male subjects were allocated to either a placebo (P) or a vitamin C (VC) group. The VC group consumed 200 mg of ascorbic acid twice a day for 14 days prior to a bout of exercise and for the 3 days after exercise. The P group consumed identical capsules that contained 200 mg lactose. Subjects performed 30 min of downhill running at a gradient of –18% and recovery was monitored for up to 3 days after exercise. Plasma VC concentrations in the VC group increased following supplementation. Nevertheless, downhill running provoked a similar increase in circulating markers of muscle damage (creatine kinase activity and myoglobin concentration) and muscle soreness in P and VC groups. Similarly, although downhill running increased plasma interleukin-6, there was no effect from VC supplementation. These results suggest that vitamin C supplementation does not affect interleukin-6 concentrations following eccentric exercise that has a low metabolic component.

 

[SupremeSportsEnhance]

Ok, this study is by far the most interesting, but unfortunately looks like more bad news for Vitamin C:



British Journal of Nutrition (2006), 95:976-981 Cambridge University Press
Copyright © The Nutrition Society 2006
doi:10.1079/BJN20061732

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Research Article

Ascorbic acid supplementation does not attenuate post-exercise muscle soreness following muscle-damaging exercise but may delay the recovery process
--------------------------------------------------------------------------------
Graeme L. Closea1 c1, Tony Ashtona2, Tim Cablea1, Dominic Dorana1, Chris Hollowaya1, Frank McArdlea2 and Don P. M. MacLarena1


a1 Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Henry Cotton Campus, 15–21, Webster Street, Liverpool L3 2ET, UK
a2 School of Clinical Sciences, Division of Metabolic and Cellular Medicine, University of Liverpool, Liverpool L69 3GA, UK
Article author query
close gl
ashton t
cable t
doran d
holloway c
mcardle f
maclaren dpm


Abstract
Exercise involving lengthening muscle actions, such as downhill running, results in delayed onset muscle soreness (DOMS), which may be attributable to reactive oxygen species (ROS). Although exercise causes oxidative stress, any link between ROS and DOMS remains speculative. There is emerging evidence to suggest that ROS play an important physiological role, assisting in the recovery process and protecting the cell from future damage; however, this has not been fully established. Despite this uncertainty as to the precise role of ROS, attempts to prevent post-exercise ROS production through antioxidant intervention are still common. The study investigated the effects of ascorbic acid supplementation on ROS production and DOMS following downhill running. Subjects were assigned to two groups. The ascorbic acid group (group AA) received 1 g ascorbic acid 2 h pre-, and for 14 d post-downhill running, whilst the placebo group (Pl group) received a placebo. Blood samples were drawn pre-supplement, pre- and post-exercise, and then 1, 2, 3, 4, 7 and 14 d post-exercise for analysis of ascorbate, malonaldehyde and total glutathione. DOMS was assessed using a visual analogue scale and pressure algometry. Muscle function was assessed using isokinetic dynamometry. Plasma ascorbate was elevated throughout in group AA compared with the Pl group. Downhill running resulted in DOMS in both groups. Muscle function was impaired post-exercise in both groups, although a delayed recovery was noted in group AA. Malonaldehyde increased 4 d post-exercise in the Pl group only. Ascorbic acid supplementation attenuates ROS production following downhill running, without affecting DOMS. Furthermore, ascorbic acid supplementation may inhibit the recovery of muscle function.