A man who is showing athletes how to use advances in sports nutrition to produce dramatic improvements in their performances
That man is Richard Kreider, a soft-spoken amiable southerner who toiled for many years at Old Dominion University under the protective wing of the man often called the 'living legend' of ergogenic research - Mel Williams. Kreider has now moved on to the campus of the University of Memphis and has fired up a fine new investigative team in the town where a dead rock and roll star is still King. It's already clear that Kreider's work is going to help a variety of different athletes, including runners, set some sparkling new PBs.
Recently Kreider and his helpers divided 52 NCAA Division IA football players into four groups. During five weeks of intensive strength training, members of one group used no nutritional supplements, a second group wolfed down extra carbohydrate, a third swallowed 20 grams per day of pure creatine monohydrate (in a product called Phosphagain), and a fourth group ingested 25 grams of creatine monohydrate (in yet another formula called PhosphagainII).
After five weeks, the two creatine groups improved their 1-RM bench press (the maximum amount of weight which could be pressed successfully one time) by 100 per cent, compared to the group which used no supplements! The creatine lifters also advanced their 1-RM bench-press power by 33 per cent, compared to those who supplemented with carbohydrate. Creatine supplementation had produced significantly larger increases in maximal strength, a great advantage for linemen who want to toss halfbacks around like rag dolls. Creatine also increased lean-tissue mass: placebo takers advanced muscle mass by one pound during the five-week study and carbo-supplementers bulked up by the same amount, but Phosphagain users expanded by 5.5 pounds and PhosphagainII players added 7 pounds.
Creatine effects in the pool
Kreider has also documented the benefits of creatine for weightlifters and swimmers. In his work with resistance trainers, creatine improved body composition and upgraded overall strength. In the swimming research, elite junior national-class swimmers improved their 100-metre sprint times by a remarkable .93 seconds and boosted basic arm- and shoulder-muscle power by up to 8 per cent after they supplemented their diets with creatine. Swimming coaches are catching on: University of Minnesota swimmers began supplementing with creatine this past season and were able to seize the Big-Ten championship from the University of Michigan for the first time in many years.
True, Kreider's not the only one who has demonstrated the benefits of creatine. British Olympic gold medallists Linford Christie and Sally Gunnell 'loaded up' with creatine during their pre-Olympic training, and research carried out by such eminent scientists as Paul Greenhaff at the University of Nottingham and Eric Hultman at the renowned Karolinska Institute in Stockholm has linked creatine supplementation with heightened athletic capacity.
And positive results with creatine just keep flowing in. In recent work carried out at Kent State University in Ohio, seven physically active men consumed 20 grams of creatine per day for five days. This creatine supplementation boosted maximal strength of the calf muscles by 10 per cent and also raised calf-muscle strength during repeated exertion (20 30-second isometric contractions) by 11 per cent, an indication that creatine could augment muscular performance during both all-out and repetitive activity. And up-to-date research just completed at the University of Toronto found that 20-gram doses of creatine taken for five days improved endurance during high-intensity cycling by about 10 per cent (from 131 to 143 seconds) and also hiked anaerobic capacity by 8 per cent.
What about creatine effects for runners?
All of these positive results are excellent, but can creatine really help 5-K, 10-K, and even marathon runners - who for the most part want continuous, moderately intense outputs of energy, not the explosive bursts which creatine seems to readily provide? Research has shown that creatine can raise running velocities during 1000-metre intervals and can improve recovery between intervals, an effect which - by raising training quality - should improve distance performances.
'Since investigations have also linked creatine with increases in muscle mass, it's possible that creatine may help runners maintain muscle mass more effectively during the training season,' says Richard Kreider. That's an effect which should be good both for running economy and the preservation of a healthy immune system. 'Since creatine helps athletes synthesise energy more quickly in their muscle cells, creatine supplementation should also help endurance athletes handle hills more effectively during races, recover from mid-race surges more rapidly, and kick more powerfully toward the finish line,' Kreider adds.
Although Kreider believes that creatine can help runners, he doesn't think the chemical should be taken 'straight'. As he points out: 'It's best to take creatine and carbohydrate simultaneously. Carbohydrate actually helps the body assimilate creatine more readily (carbohydrate increases blood levels of insulin, and insulin 'pushes' creatine into muscle cells), and in turn creatine promotes better carbohydrate (glycogen) storage in muscles.' Fortunately, a product manufactured by a company called Experimental and Applied Sciences (EAS), makes this process easy. Obtainable at health-food stores, the stuff, called 'Phosphagen HP,' comes in a powder, a scoopful of which can be mixed with six to eight ounces of water or juice to provide a carbo-creatine 'wallop' of 35 grams of carbohydrate and 5.25 grams of creatine.
Phosphate in the trenches
However, the carb-creatine combo are just two parts of the supplement triad recommended for athletes by Kreider. The third component is sodium phosphate.
Interest in sodium phosphate's potential ability to enhance endurance actually dates back to World War I, when German scientists believed that phosphates boosted energy levels in muscle cells and German soldiers were given phosphate salts in an attempt to boost their stamina. Infantrymen reported greater vigour in battle, and during the 1920s and 1930s, German athletes ingested large quantities of phosphate routinely and contended that their performances were markedly improved thereby.
During the same period, there was also considerable interest in a compound called lecithin (phosphatidyl choline), which has both a high phosphate and choline content.
While phosphate was supposed to increase energy, choline was theorised to strengthen muscle contractions. That theory made a certain amount of sense since the human body uses choline to form acetylcholine, a neurotransmitter which stimulates muscles to contract (we'll report on the possible benefits of choline in a future issue of Sports Performance Bulletin).
Research into the effects of phosphate and choline, which was generally positive but deeply flawed methodologically, slackened during World War II, and phosphate work didn't revive until the late 1970s, when a University of Florida research team noted an interesting fact: when athletes ingested extra sodium phosphate, concentrations of a chemical called 2,3-DPG increased in their red blood cells. 2,3-DPG is important for athletes because it makes it easier for red cells to 'release' oxygen to muscles, allowing muscles to generate more energy aerobically. Indeed, the Florida study showed that after sodium-phosphate supplementation athletes could utilise more oxygen at a given heart rate and that there was less stress on the heart during exercise.
The miracle substance
The 2,3-DPG findings stimulated the Florida team to conduct the first well-controlled study on phosphate loading and athletic performance, and the results were startling. In this research, sodium-phosphate ingestion boosted serum phosphate levels, raised 2,3-DPG, lifted VO2max by up to 12 per cent, lowered lactate levels when athletes ran on treadmills at tough intensities (an indication of increased oxygen delivery to the muscles), upgraded total work output, and promoted better endurance during rugged uphill running.
Later research published in Great Britain revealed that blood phosphate was about 33 per cent higher in elite marathon runners, compared to non-elite marathoners, and that phosphate was about 33 per cent below-normal in runners who collapsed after running a half marathon. This study suggested that there was a direct link between blood phosphate levels and running performance; the higher the levels, the faster the running velocity, and the lower the risk of collapsing after a race.
More evidence that sodium phosphate could improve endurance performance was uncovered in another study carried out at the University of Florida, in which individuals attempted to cycle for as long as possible at an intensity of about 65 per cent VO2max (76 per cent of max heart rate). Subjects who took in no water or phosphate during the exertion lasted only 130 minutes, those imbibing water but no phosphate continued for 141 minutes, and individuals taking in water and phosphate endured for 165 minutes. In this investigation, phosphate loading also decreased perceived exertion (the exercise felt easier when phosphate was on board) and expanded the utilisation of oxygen by leg muscles.
In a neat bit of research carried out by Kreider himself, six days of sodium phosphate supplementation at an intake rate of four grams per day actually 'blood-doped' a group of seven elite runners whose VO2max values rested at a lofty 74 ml/kg.min. In these runners, phosphate supplements increased blood-haemoglobin levels by 5 per cent (from 14.0 to 14.74 g/dl), possibly because phosphate increased the rate of formation of new red cells or prolonged red-cell life.
More strikingly, the phosphate ingestion hiked VO2max by 9 per cent (from 74 to 80 ml/kg.min) and boosted ventilatory anaerobic threshold (similar to lactate threshold) by a whopping 12 per cent. Performance times improved by about 12 seconds in a five-mile race after phosphate loading, although the effect wasn't quite statistically significant, probably due to the small number of subjects. Another problem was that mile splits were called out to the runners as they ran the five-mile competition, which may have limited the phosphate-supplemented runners psychologically (if phosphates added zip to their race speeds, they may have thought they were running too far above their usual abilities when they heard their unusually fast splits called out; thinking they were going too fast, they consequently slowed down).
In this study, performance times in the five-mile race ranged from seven seconds slower to 35 seconds faster after phosphate loading, indicating that the 'up' side of performance following phosphate ingestion was considerably broader than the 'down' side. An interesting aspect of this research was that even though the athletes ran faster after phosphate supplement-ation, they used less oxygen while running at race pace, an indication of improved running efficiency (economy).
As if that wasn't enough, Kreider carried out yet another study, this time with highly trained endurance cyclists, in which five days of sodium-phosphate supplementation (at a dosage of 4 grams per day) raised VO2max by 9 per cent, hoisted lactate threshold by 10 per cent, and improved 40-K race times by 8 per cent (from 45:45 to 42:15).
Getting specific
So what's the bottom line? Carbs, creatine, and phosphate combine to create a performance powerhouse for the endurance athlete. Carbohydrate provides the leg-muscle glycogen needed for quality performances, creatine promotes better interval workouts and probably helps with surges during races, and phosphate lifts maximal aerobic capacity and lactate threshold and improves performance times
If you decide to take in all the carbohydrate you really need and supplement your diet with creatine and phosphate as well (and your doctor says it's okay), here's what to do:
1) If you're engaged in strenuous training, you should ensure that you're taking in at least 16 calories (four grams) of carbohydrate per pound of body weight per day. If you weigh 120 pounds, that's 480 grams of carbs, or 1920 calories.
2) To 'load' yourself with creatine, shoot for a creatine intake of 20 grams per day for four to five days. This daily dose of 20 grams should be taken in four separate doses of five grams each. Since it's best to take creatine with carbohydrate, an excellent way to combine the two would be to mix four glasses of the aforementioned Phosphagen HP, as directed on the product container. Follow up the loading with your most intense training period or an important competition. Your muscle-creatine levels should stay high for about five weeks or so, but Kreider recommends loading before major races which occur within that time span.
3) To maintain adequate muscle-creatine concentrations between loading periods, ingest two to five grams of creatine per day. The easiest way to do this is to drink one glass of Phosphagen HP daily.
4) To boost yourself with phosphate, try taking in four to six grams of sodium phosphate per day for three to four days. The simplest way to do that is to buy a product called Phos Fuel, produced by Twin Laboratories, Inc. Each Phos Fuel capsule contains one gram of sodium phosphate, so you will have to take four to six capsules per day, preferably at different times. This phosphate load will 'wash out' of your system in about two weeks, after which you'll need to load again if you want high-phosphate levels.
As with creatine, take in phosphate before intense training periods and major competitions. Be cautious, though: some athletes have digestive-system problems when they utilise phosphates. It's best to start with a small dose of one to two grams daily while your system gets used to it (make sure you try sodium phosphate during training; don't wait until just before a competition). Also be aware that chronic phosphate supplementation, combined with a low intake of calcium, can trigger a calcium deficiency, so you shouldn't be taking phosphate all the time, and you should make sure that your calcium intake is more than adequate.
5) Of course, the idea is to load with creatine and sodium phosphate simultaneously during the four to five days leading up to a big race, not use them at separate times (in case you were in any doubt)
6) Use sodium phosphate - not calcium phosphate. Research has failed to link calcium phosphate with improvements in performance.
7) At this point, you must be wondering about which competitive events are actually helped by carbohydrate, creatine, and phosphate ingestion. We know that carbo-loading assists athletes in exertions which last for an hour or more (or more than 40 to 45 minutes or so if the course is very hilly). Creatine should be beneficial during strenuous exercise lasting longer than about 10 seconds, and phosphate should provide a boost at running distances of 800 to 1000 metres or greater.
8) Carbs, creatine, and phosphate are all legal. You won't be banished from competition or have your prizes taken away if you swallow large quantities of any or all of these three performance-boosters.
Owen Anderson