In a previous article on sodium bicarbonate supplementation for combat sports, I stated a few different ways in which combat sports athletes fatigue during training or during a fight. The cause of fatigue that was addressed in that article was acidosis, and an explanation was given on how sodium bicarbonate can potentially reduce fatigue.
One of the other causes of fatigue I mentioned in that article was muscle phosphocreatine depletion, which is the one we’re concerned with in this article.
The adenosine triphosphate phosphocreatine (ATP-PC) system is the dominant system during explosive activities of short duration. It has the highest rate of ATP production out of all the energy systems, and has the greatest power potential (17). This is because it utilises energy acquired via intramuscular stores of ATP and creatine phosphate.
However, the amount of energy obtainable through this system is very short-lived, being the dominant system for about the first 6-7 seconds of high-intensity work.
When phosphocreatine stores begin to deplete during high-intensity exercise, we are unable to resynthesize ATP at the rapid rate at which we require it, and our performance declines as the available energy is inadequate.
An increased dietary availability of creatine results in an increase in total creatine and phosphocreatine in the muscle (21). This availability of creatine and creatine phosphate are an integral part of energy metabolism during high-intensity exercise (22)
The key factor in supplying energy to rephosphorylate adenosine diphosphate (ADP) to ATP during and after intense exercise is the levels of phosphocreatine stored in muscles (8).
Therefore, increasing intramuscular phosphocreatine stores is of the utmost importance if we are to delay phosphocreatine depletion and perform at a higher intensity for a longer duration. Supplementing with creatine may be a viable option to achieve this (9).
What is Creatine?
Creatine is a compound which is both made within our bodies from amino acids and obtained through diet in foods like meat and fish (18), or taken as a supplement to potentially boost high-intensity efforts during exercise. Therefore, creatine is a normal component in our muscles.
Creatine is synthesized in our kidney, pancreas and liver from the three amino acids; L-methionine, Glycine and L-Arginine. Around 90-95% is then delivered and stored in our muscle, while the remainder is transported to the brain, heart, testes and other tissues (2, 15, 20).
Creatine as a Supplement
The interest in creatine supplementation was first aroused when researchers (1) showed that 20g per day for 5 days successfully increased total muscle and phosphocreatine content by 15-20%.
Since then, creatine supplementation has consistently shown to increase muscle phospocreatine content at rest (1), which is related to improved anaerobic performances – particularly those with a high-intensity, intermittent nature (2) such as Thai boxing and other combat sports.
In fact, most studies investigating the benefits of creatine have reported a significant performance increase in strength and power tasks, as well as sprints other work involving multiple sets of maximal effort.
These performance improvements have been attributed to increased muscle total creatine and phosphocreatine content which utimately results in a greater resynthesis of phosphocreatine, improved metabolic efficiency (18) and greater training adaptations due to the enhanced quality and volume of work performed (19).
What Type of Creatine is Best?
Creatine monohydrate is the most commonly used, and most studied form of creatine. However, companies are constantly bringing out new formulations and combinations which claim to work better than creatine monohydrate.
Some of the most popular products include:
Creatine ethyl ester
Creatine + sodium bicarbonate,
Creatine + glycerol
Creatine + glutamine,
Creatine + β-alanine,
There are far too many to mention here.
The bottom line is, there is very little evidence that any of those combinations and formulas increase performance markers or muscle total creatine more than traditional creatine monohydrate (10, 11, 12). Their prices are also hugely inflated with mainly unsubstantiated claims.
All references used in this article refer to the supplementation of creatine monohydrate.
Short Term Effects
Numerous reviews (15, 17, 23) have confirmed that the majority of short-term studies confirm a significant performance increase in strength, power, sprints and work involving maximal effort over multiple sets.
Researchers (23) have reported that 25g creatine supplementation per day for 7 days significantly increased the amount of total repetitions during all 5 sets of bench press to failure, and significantly improved peak power output in jump squats when compared to placebo.
An investigation into the effects of creatine supplementation (20g/day x 6 days) on the effects of intermittent high-intensity soccer-specific drills (24) showed a consistent improvement in repeated sprints (15m sprint/30s recovery). This study also demonstrated an unchanged counter-movement jump performance following an intermittent endurance test in the creatine supplementation group, with the placebo group showing a decrease.
Creatine supplementation of 15g/day x 5 days showed significant improvements in maximal power and work performed in elderly (3.7% and 4.1% respectively) and younger subjects (2.0% and 5.1% respectively) during five all-out 10s sprints with 60s recovery.
Short term creatine supplementation enhances performance in a multitude of laboratory and sporting tasks via an increase in total creatine and phosphocreatine levels in skeletal muscle (22).
Long Term Training Adaptations
We’ve looked at the short-term supplementation effects, so now let’s examine the long term training adaptations associated with creatine use.
42 days of creatine supplementation (0.3g/kg bodyweight) brought on superior increases than the placebo group in several athletic abilities during male and female track and field pre-season training. Performance increases were seen in counter-movement jump height and power index, average cycle power and peak power, total cycle work, cycle initial rate of power production, and lean body mass (26).
26 days of creatine supplementation (20g/day x 4days and 5g/day x 22days) resulted in significant 3-rep max strength gains in both absolute terms and relative to body mass, and an increase in body mass and lean body mass in 18 trained powerlifters (25). The study also demonstrated an increased amount of total reps in the creatine group, while no changes were seen in the placebo group.
21 days of 7.7g/day of creatine significantly improved several factors associated with short-duration, high-intensity activity including more total work until fatigue, peak force, peak power, and elevated mean peak power for a longer period (27).
Evidence suggests that supplementing with creatine allows the athlete to train at a higher intensity, and promotes greater training adaptations over time via a more intense stimulation of the musculature (22, 27).
Supplementing with creatine generally results in retention of water in the muscle. This is due to an osmotic effect of creatine (5) and usually leads to a body mass increase of around 0.5-2.0kg in short-term studies (22).
This initial increase in body mass is due to fluid retention. However, long-term studies have shown increases in fat-free mass and/or muscle fiber size with no disproportional increase in total body water. This suggests that the extra mass beyond the initial gain is in fact muscle mass, not added water retention.
So, an increase in body mass can be expected, but bear in mind that several studies are using hypertrophy protocols to increase muscle mass, and some so-called strength-training protocols are actually hypertrophy programs too.
The time it takes muscle creatine levels to return to pre-supplementation levels has been reported to be 4 weeks (13). In that study, total muscle creatine levels remained significantly elevated for 2 weeks after the supplementation ceased, and returned to baseline levels 4 weeks post supplementation.
These results are in accordance with other studies who also found the washout time to be 28 days (14) following a 5 day loading phase, and 30 days (15) following a 6 day loading phase (20g per day) and a 30 day (2g per day) maintenance phase.
Therefore, if a muay Thai fighter or other combat sports athlete does not want to carry the extra body weight into the fight, supplementation should cease 4 weeks prior to the weigh-in.
Extra body mass gained by fluid retention from creatine supplementation may be problematic for athletes who find it difficult to cut weight for a fight.
The way I would approach the situation is as follows;
Supplement with creatine during fight-training to maximise training adaptations. Stop supplementation 4 weeks prior to the weigh-in. Start the loading protocol again immediately after the weigh-in.
If, however, you feel you can cut an extra kilo or two, or you fight in the upper division, you can continue supplementation right the way through.
The reason I suggest creatine loading immediately after the weigh-in is this; although you may want to cease supplementation 4 weeks prior to the weigh-ins, repeating the loading phase protocol of 20g per day (4x5g doses) after the weigh in can actually increase muscle phosphocreatine prior to competition as the first 48 hours of supplementation is where subjects see the most rapid increases (1).
Additionally, creatine has been shown to restore physical performance post-weigh in, in well-trained wrestlers who underwent a rapid weight loss (weight cutting) protocol of 4.5-5.3% body weight reduction. The wrestlers ingested creatine + glucose during the 17-hour recovery period and increased high-intensity performance markers by 19% when compared to the glucose only group. There were no significant changes in body weight increase between the two groups (16).
This evidence suggests that creatine supplementation post-weigh in may be beneficial to fighter performance. However, if the fight is less than 15 hours after the weigh-in then the uptake of creatine and subsequent performance increase may be minimal.
Augmenting The Effects
A study on the affects of carbohydrate ingestion on muscle creatine accumulation during creatine supplementation (7) showed that accumulation can be increased by 60% when 5g of creatine is ingested with 93g of simple carbohydrates when compared with the ingestion of 5g of carbohydrate alone. This augmentation occurs as a result of a stimulatory affect of insulin on muscle creatine transport.
Non-Responders and Dietary Intake
Several studies have been reviewed to ascertain the responsiveness of creatine supplementation in individuals (4). Results showed that 20-30% of individuals don’t respond to creatine supplementation i.e. they show less than an 8% increase in total muscle creatine after a 5-day loading phase of 20g per day.
The increase in creatine storage when supplementing depends directly on the amount of muscle creatine prior to supplementation. The increase in subsequent performance is positively correlated with the increase in storage (19).
Some individuals have high levels of intramuscular creatine prior to creatine supplementation. Athletes who eat a diet high in meat and fish will naturally have elevated creatine levels within their muscle cells and may see little or no benefit when supplementing with creatine (5).
The table below shows creatine content within some common foods.
Conversely, vegetarians and vegans generally respond extremely well to creatine supplementation due to the lack of creatine-rich foods within their diets.
Genetic variations in creatine transport capacity also affects pre-supplement levels (2).
It should be noted that in studies which report no significant ergogenic effects have still observed an increase in performance, albeit a small, non-significant one (i.e. 1-7%) (22).
Safe and effective supplement for Thai boxers and other combat sports athletes
Consistently shown to improve high-intensity exercise of multiple bouts
Should be consumed with simple carbohydrates to improve uptake
Fighters should be aware of the potential added body weight gained from supplementation, and cycle accordingly
Wash out time is 4 weeks
Can increase muscle phosphocreatine levels and performance after a weigh-in
Meat and fish are the best sources of creatine in an ordinary diet
Athletes with high levels of muscle creatine prior to supplementation may not respond well to supplementation
Creatine Type: Monohydrate
Loading Phase (5days): 20g/day (4x5g + 100g glucose)
Maintenance Phase (continuous): 5g/day + 100g glucose
4 weeks out: Cease supplementation
Post-weigh in: 20g/day (4x5g + 100g glucose)
If a little weight gain is not an issue, creatine should be supplemented right the way through to the fight for more efficient phosphocreatine resynthesis at very little cost in terms of weight.