Research by the University of Oklahoma March 11th, 2009




Very recent, preliminary data from the University of Oklahoma indicates that Game Time improves both anaerobic and endurance performances. Specifically, athletes can expect 10-12% increases in workout intensity and duration 30 minutes after taking a packet of Game Time (1,2). Furthermore, athletes who use Game Time while training for a period of at least 3 weeks can expect significant improvements in VO2max, body composition, and critical velocity, which is the running velocity that can be maintained for at least 1 hour and is a measure of endurance performance.





In a series of recent studies conducted at the University of Oklahoma (1,2), Game Time has been shown to increase athletes’ time-to-exhaustion during high-speed running by 10-12% (2). In addition, Game Time improved the athletes’ anaerobic running capacity by 11% (1), which is the energy in muscle associated with running at maximal speed.


What does this mean for athletes? It means they can run farther and faster after taking Game Time. What athlete wouldn’t benefit from that? For example, 30 minutes after taking Game Time, a wide receiver would be able to maintain his route at maximal speed for an additional 13 yards*.  A punt or kickoff returner would be able to sustain his initial running speed for an additional 45 – 78 yards†.  A running back could expect a 10-12% increase in open-field yardage per run‡. For basketball players, coaches could expect a sustained ability run fast breaks during the crucial minutes of a close game after taking Game Time. Essentially, basketball players could count on Game Time to help them avoid fatigue and sustain their explosive running abilities during the course of a game.


  1. Fukuda DH, Smith AE, Kendall KL, Graef JL, Moon JR, Stout JR. Acute effects of a pre-exercise supplement on critical velocity and anaerobic running capacity in college-aged men and women. Journal of Strength and Conditioning Research, in review.


  1. Smith AE, Fukuda DH, Kendall KL, Graef JL, Moon JR, Stout JR. Acute pre-exercise supplementation improves times to exhaustion during high-intensity running in men and women. Journal of Strength and Conditioning Research, in review.


* Estimate is based on the average increase in anaerobic running capacity (expressed in kilometers and converted to yards) observed as a result of taking Game Time compared to a placebo (1).


† Estimates are based on the average increases in distances run (expressed in kilometers and converted to yards) observed as a result of taking Game Time compared to a placebo (2).


‡ Estimates are based on the average percent increases in times-to-exhaustion (seconds) observed as a result of taking Game Time compared to a placebo (2).




With the possible exceptions of long-distance events (running, cycling, skiing, and rowing), many sports involve a heavy “anaerobic” component. The term anaerobic by definition means “without oxygen,” and refers to short bursts of high-intensity activity, such as a maximal 40 yard sprint or a fast break down the basketball court. Anaerobic is used to describe these activities, because the energy demands in skeletal muscle are so quick that the body does not have time to utilize oxygen. Thus, the body must resort to the fastest metabolic pathways, such as the phosphocreatine and glycolysis systems, for energy transfer. Not surprisingly, the phosphocreatine system uses creatine phosphate to replenish energy stores, whereas the glycolysis system uses the breakdown of muscle glycogen and blood glucose for energy. Neither of these two energy systems require oxygen, thus, they are the metabolic pathways that most anaerobic athletes rely on, such as football, basketball, hockey, baseball, softball, and volleyball players.


Anaerobic performance usually involves high power activities that range from a split second up to 2 or 3 minutes. Examples include a basketball guard driving toward to the hoop and exploding off of the court to dunk a fast break, football linemen exploding off the line of scrimmage to block a defender, a baseball player rounding the bases during a triple, or an 800-meter sprinter finishing under 2 minutes. The intensities of these activities are nearly maximal and often exhaustive. In fact, it is not uncommon to completely deplete the phosphocreatine stores in the working muscles during maximal anaerobic performances (2). Although, it may take up to 2 hours of moderate to high intensity exercise to deplete muscle glycogen stores (1), it is not hard to imagine how glycogen stores could run very low for a football player in the 4th quarter, a soccer player in the last minutes of the 2nd half, or a baseball player after a double- or triple-header. Consequently, no matter how well-trained the athlete is, energy depletion is unavoidable without proper nutrition. Therefore, any type of nutritional strategy to prolong the depletion of phosphocreatine and/or muscle glycogen would be welcome from any athlete who wishes to improve and sustain their anaerobic performance.


Obviously, athletic performance during the competition is the most important aspect of sports. However, if athletes are able to practice and train harder at higher intensities in preparation, the competition outcome is usually better. In fact, high-intensity interval training (HIIT) is becoming more-and-more popular and effective for increasing performance (11). HIIT is a time-efficient type of training that involves short bursts of high-intensity exercise with brief rest intervals in between. HIIT training not only mimics most anaerobic sports, but it has also been shown to improve long-duration aerobic endurance performance as well (11). Therefore, like the athletic events themselves, HIIT relies on the anaerobic metabolic pathways and can benefit from the same nutritional strategies to prolong exercise. After all, HIIT at higher intensities for longer durations will generally equate to better on-field or on-court performances.


Like all athletics, rest and recovery can be just as important as training. High-intensity practices will always elicit some level of muscle damage and inflammation (8). Sometimes the extent of damage is perceivable by the athletes, and sometimes it is not. If proper rest and nutritional strategies are not prescribed no matter how the athlete feels, this can easily lead to overreaching and overtraining, which can result in performance decreases (7). Therefore, nutritional supplementation during and after intense practices and training are convenient and effective methods to help athletes recover.


Training Day nutritional supplements are designed to enhance athletic performance and improve subsequent recovery. The 3 products offered by Training Day are Pre Season, Game Time, and Post Game. These products were specifically designed for athletes to improve their performance, increase their training intensity, and augment recovery. For example, the Game Time formulation includes cordyceps sinensis, arginine, creatine, and little caffeine to improve respiration, blood flow, phosphocreatine stores, and endurance times, respectively. Creatine and caffeine are probably the two most scientifically studied nutritional supplements, and the results are largely conclusive that these ingredients work to improve athletic performance (3,12). Therefore, Game Time is best taken 30 minutes prior to practices, training sessions, or games. In fact, perhaps the most convincing evidence that really sets Training Day apart from other nutritional supplements is that Corr-Jensen Laboratories, Inc., have funded two clinical trials that have tested Game Time. These recent studies (4,10) conducted at the University of Oklahoma showed that Game Time improved high-speed running times to exhaustion by 10 – 12% (10) and increased the anaerobic running capacities of the athletes who participated by 11% (4). Therefore, these results indicated that Game Time indeed improves high-speed, anaerobic running performances – which are improvements that almost all athletes can benefit from.


Preseason contains creatine, high-glycemic carbohydrates, and amino acids to provide the energy stimulus that helps athletes peak right as the season starts. As mentioned before, there is a plethora of evidence indicating that creatine improves performance in anaerobic athletes (3). There are even data to suggest that high-glycemic carbohydrates help skeletal muscle to absorb creatine (5,9). Also, much evidence exists for the use of high-glycemic carbohydrates during and after high-intensity exercise to maintain and replenish muscle glycogen stores (13), which is critical for anaerobic athletes. Therefore, although Pre Season is designed for use prior to the season to help athletes peak at the right time, it can certainly be used during the season as a replenishment drink taken slowly during or immediately after intense practices, workouts, or games.


Post Game is Training Day’s gel-encapsulated amino acid supplement. Amino acids are the building blocks of proteins that make up skeletal muscle and just about everything else that is required to build, maintain, and repair body tissues. Therefore, Post Game is critical for recovery for athletes. In fact, the timing for taking amino acids (i.e., Post Game) after workouts and games is a critical issue in the scientific literature (6), and it is commonly called nutrient timing.  Athletes should be encouraged to take Post Game immediately after intense workouts and games. There is a critical window of about 1 hour after high-intensity training that requires carbohydrate and amino acid ingestion to optimize replenishment, recovery, and subsequent performance (6). Therefore, Post Game should be on-hand for athletes immediately after their workouts.


Overall, the general recommendations for “anaerobic” athletes are to take Game Time 30 minutes prior and Preseason and Post Game immediately after their workouts, practices, and/or competitions. This general strategy will utilize the formulations of Training Day to optimize performance and recovery.




Based on very recent, preliminary data, Game Time can also be used during a training period to increase endurance performance in athletes. Phase II of the studies conducted at the University of Oklahoma have just been completed, and the results are in!


Twenty-three subjects were split into 2 groups: Game Time and placebo. Both groups took their supplements 3 times per week for 3 weeks, 30 minutes prior to training. The training consisted of high-intensity interval running, with five 2-minute running intervals and 1 minute of rest and undulating intensities between 90% and 110% of the running speed achieved during the VO2max test. The critical velocity tests, body composition testing, and VO2max tests were performed before and after the 3 weeks of training.


Game Time in conjunction with 3 weeks of high-intensity interval running improved critical velocity by 4% (which is the running velocity that can be maintained for at least 1 hour), decreased percent body fat by 15% while increasing lean body mass by 4%, increased VO2max by 17%, and increased the athletes’ training volume by 12% when compared to a placebo.


Overall, these findings indicate that athletes can expect significant improvements in endurance performance while taking Game Time regularly before their workouts.




  1. Bouckaert J, Jones AM, Koppo K. Effect of glycogen depletion on the oxygen uptake slow component in humans. Int J Sports Med 25(5):351-356. 2004.


  1. Cramer JT. Bioenergetics of Exercise and Training. In: Essentials of Strength Training and Conditioning (3rd Edition), Eds. Baechle TR, Earle RW. National Strength and Conditioning Association. Human Kinetics Publishers, Champaign, IL. Pgs 21-39. 2008.


  1. Cramer JT. Creatine supplementation in endurance sports. In: Essentials of Creatine in Sports and Health, Eds. Stout JR, Antonio J, Kalman D. International Society of Sports Nutrition. Humana Press, Totowa, NJ. Pgs 45-99. 2008.


  1. Fukuda DH, Smith AE, Kendall KL, Graef JL, Moon JR, Stout JR. Acute effects of a pre-exercise supplement on critical velocity and anaerobic running capacity in college-aged men and women. J Strength Cond Res, in review. 2009.


  1. Green AL, Hultman E, Macdonald IA, Sewell DA, Greenhaff PL. Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. Am J Physiol 271:E821-E826. 1996.


  1. Kerksick C, Harvey T, Stout J, Campbell B, Wilborn C, Kreider R, Kalman D, Ziegenfuss T, Lopez H, Landis J, Ivy JL, Antonio J. International Society of Sports Nutrition position stand: Nutrient timing. J Int Soc Sports Nutr 3(5): 17. 2008.


  1. Meeusen R, Watson P, Hasegawa H, Roelands B, Piacentini MF. Brain neurotransmitters in fatigue and overtraining. Appl Physiol Nutr Metab 32(5):857-864. 2007.


  1. Negro M, Giardina S, Marzani B, Marzatico F. Branched-chain amino acid supplementation does not enhance athletic performance but affects muscle recovery and the immune system. J Sports Med Phys Fitness 48(3): 347-351. 2008.


  1. Preen D, Dawson B, Goodman C, Beilby J, Ching S. Creatine supplementation: a comparison of loading and maintenance protocols on creatine uptake by human skeletal muscle. Int J Sports Nutr Exerc Metab 13:97-111. 2003.


  1. Smith AE, Fukuda DH, Kendall KL, Graef JL, Moon JR, Stout JR. Acute pre-exercise supplementation improves times to exhaustion during high-intensity running in men and women. J Strength Cond Res, in review. 2009.


  1. Smith AE, Walter AA, Graef JL, Kendall KL, Moon JR, Lockwood CM, Fukuda DH, Beck TW, Cramer JT, Stout JR. Effects of beta-alanine supplementation and high-intensity interval training on endurance performance and body composition in men: a double-blind trial. J Int Soc Sports Nutr 11(6): 5. 2009.


  1. Sokmen B, Armstrong LE, Kraemer WJ, Casa DJ, Dias JC, Judelson DA, Maresh CM. Caffeine use in sports: considerations for the athlete. J Strength Cond Res 22(3): 978-986. 2008.


  1. Wakshlag JJ, Snedden KA, Otis AM, Kennedy CA, Kennett TP, Scarlett JM, Kallfelz FA, Davenport GM, Reynolds AJ, Reinhart GA. Effects of post-exercise supplements on glycogen repletion in skeletal muscle. Vet Ther 3(3):226-234. 2002.




Assistant Professor and Director of the Biophysics Laboratory

Department of Health and Exercise Science

University of Oklahoma


Scientific Advisor for Training DayTM and Corr-Jensen Laboratories, Inc.


3 Responses to “Research by the University of Oklahoma”

  1. Chris:

    Why is td not supposed to used by someone under 18?

  2. Training Day:

    Good question! The answer has to do with the FDA. Training Day is required to put that on every package because it is a dietary supplement. There are many young athletes that use Training Day. A study done on athletes who were 18 years of age at the University of Oklahoma showed no adverse side effects.

  3. Admiring the time and energy you put into your weblog and in depth information you offer. It’s good to come across a blog every once in a even though that isn’t the same old rehashed material. Great read! I’ve bookmarked your web site and I’m adding your RSS feeds to my Google account.

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