PRE|CHU 'Science'

The truth about CHU’s and pre-workout

PRE-CHU is the first full-strength, chewable pre-workout supplement. Yes, you read that right, CHEWABLE. No more water or shakers needed! Pre-workouts have been around for decades, with everyone from professional athletes to amateurs using them to get the very best out of their training sessions. But do they actually work? We dive into the science behind PRE-CHU.


What are pre-workout supplements?

Pre-workout supplements are traditionally drinks taken before a workout, training or exercise session to amplify your performance. They contain specific ingredients designed to improve focus, strength, endurance and/or work capacity.

Sadly, not all pre-workouts are created equally. Some contain un-researched and unregulated ingredients (such as those prohibited by the World Anti-Doping Agency (WADA)) which could land you with a four-year ban from competitive sports or worse, serious damage to your health. Others are often packed with bulking agents, meaning you aren’t getting what you pay for. It’s important you know what is in your pre-workout supplements, that’s why at CHU remain transparent with what is in our products. We don’t hide behind ‘proprietary blends’ and we only contain ingredients which are clinically proven to improve athletic performance.


Do I need pre-workout supplements?

Supplements are as they suggest, a supplement. This means they should be used in addition to, and not instead of, a healthy, nutritionally complete diet and a well-structured training programme. But, if you want to get the very best out of each training session, pre-workouts are essential.

So often we see events or competitions won by the smallest of margins. These competitions are merely a platform to showcase years of hard work, dedication and perseverance which occur when no-one is watching. To get there, you need to perform at your best, consistently, in every training session. That’s where PRE-CHU’s come in.


What ingredients are in PRE-CHU’s?

At CHU, we pride ourselves on only using ingredients which have been backed by valid, scientific research. So often companies promote ingredients which either have no evidence outright or have no evidence of improving athletic performance in humans. Don’t let these companies fool you! Often, these ingredients will have no benefit to your performance but will leave a sizeable hole in your wallet! So what are the main ingredients in PRE-CHU? 



Beta-alanine is modified amino-acid clinically proven to enhance muscle growth and endurance whilst reducing neuromuscular fatigue. 

How does it work?

  1. By promoting lactic acid clearance
  • During anaerobic (high-intensity) exercise muscles become more acidic. This is often known as ‘lactic acid’ or ‘the burn’.
  • This increase in acidity is thought to interfere with the muscle’s ability to contract which causes a decrease in power output and increased fatigue.
  • To prevent muscles becoming too acidic the body has several ways of reducing the acidity. These are known as ‘buffering systems’ and one of the most effective is muscle carnosine.
  • Increasing muscle carnosine levels in the muscles is known to improve exercise performance and work capacity by slowing the onset of fatigue.
    • Essentially, the more muscle carnosine you have, the better you are at preventing your muscles becoming acidic, allowing them to work harder and for longer before fatigue sets in. This can be beneficial for all maximal intensity activities such as sprinting, cycling, weightlifting or boxing. 

So why don’t PRE-CHU’s contain carnosine instead of beta-alanine?

  • Studies have shown that supplementing with beta-alanine is far better at raising muscle carnosine levels compared with carnosine itself, due to better absorption rates. Beta-alanine is quickly converted to carnosine within the muscles.
  1. By indirectly promoting muscle hypertrophy
  • Due to its ability to slow the onset of fatigue, beta-alanine supplementation is able to increase resistance training volume (e.g. the number of repetitions or “reps” for an exercise when training in the 8-15 repetition range) which is known to stimulate muscle hypertrophy.
    • One study in particular among collegiate wrestlers and football players demonstrated B-alanine supplementation enhanced athletic performance and promoted an increase in lean body mass above that of a placebo (Kern and Robinson, 2011).

To summarise, the above benefits arise due to an accumulation of muscle carnosine stores over time. This means you need to supplement beta-alanine regularly to build up maximum muscle carnosine levels. Although carnosine can be obtained from the diet, intakes vary greatly between individuals. For this reason, including beta-alanine to PRE-CHU formula was non-negotiable. Don’t just take our word for it though, check out the many 5-star reviews we’ve received from people like you who we’ve helped elevate their workouts to new limits.


A little bit of research:

In a study of 22 women, the oral administration of beta-alanine significantly delayed the onset of neuromuscular fatigue and time to exhaustion during incremental cycle ergometry tests to exhaustion after 28-days of supplementation (Stout et al., 2007). 



Caffeine is a potent stimulatory, anti-sleep compound found naturally in several foods such as coffee, chocolate and tea. It acts by binding to the receptors of adenosine (a compound within the body which gradually increases over the course of the day) blocking it from binding to its own receptors. Adenosine causes sedation and relaxation when it binds to its receptors. By blocking this interaction with caffeine, you delay fatigue, increase alertness and stimulate the central nervous system. This has been shown to have several other benefits, such as:

  • Increased power output (Cook et al., 2012)
  • Elevated anaerobic running capacity (Paton, Lowe and Irvine, 2010)
  • Improved aerobic endurance (Graham and Spriet, 1995)
  • Increased training volume and performance to failure (Duncan and Oxford, 2011)

Put simply, caffeine has been shown to increase strength and training capacity in the weight room, sprint times and running endurance. This means more stronger lifts, more reps, quicker sprint times and reduced exercise fatigue.

Caffeine can be absorbed through the lining of the cheeks and gums. This means you don’t have to wait for complete digestion in the stomach to occur to obtain the benefits. Chew your PRE-CHU’s minutes before your workout and you’re ready to go.

Caffeine dosages should be tailored to individuals. This is why at CHU we encourage you to self-dose your pre-workout to your individual tolerance, needs and form of activity. If you are new to caffeine supplements, start with four PRE-CHU’s. This way you can gauge how you respond. If four isn’t enough, increase your dose to six PRE-CHU’s, reassess and so on. Ten gummies are considered a full dose and contain ~200mg of caffeine per serving. To put this in perspective this is equivalent to approximately two and a half espresso shots.


Figure 3. The mean ± standard definition (SD) of bench press repetitions performed to failure at 60% 1RM in caffeine and placebo conditions. * P=<0.05

All data used within this infographic has been obtained from (Duncan and Oxford, 2011)


Figure 4. Mean ± SD of total weight lifted (tonnage) during bench press repetitions to failure at 60% 1RM when supplementing with caffeine vs placebo.


*P = <0.05
All data used within this infographic has been obtained from (Duncan and Oxford, 2011).

The data from this study clearly indicates caffeine supplementation significantly increases the number of repetitions performed, and therefore total weight lifted (tonnage), during maximal efforts to failure. Improving the amount of tonnage lifted during exercise is a widely-accepted way of increasing resistance training volume; which, in itself, promotes muscle hypertrophy (Krzysztofik et al., 2019). 



Citrulline is a ‘non-protein’ amino acid compound. This means it isn’t converted into structural proteins such as skeletal muscle. Instead, it is readily converted to arginine (another amino-acid), increasing its concentrations within the blood.

During intense exercise, improving blood flow to working muscles is essential for delivering oxygen and nutrients whilst removing waste products. This is enabled by nitric-oxide (NO), a natural signalling molecule, which is created when arginine combines with oxygen. Citrulline supplementation increases nitric-oxide production far greater than arginine supplementation itself, due to better rates of absorption, and is known to reduce muscular fatigue during exercise. This has been shown to significantly increase the number of repetitions achieved during exercise when compared to a control group. However, how this happens is not yet fully understood. It is believed that by improving arginine levels within the body, and subsequent nitric oxide production, blood flow is improved. This reduces lactic acid and ammonia build up, delaying the onset of fatigue and improving anaerobic athletic performance.


A study by (Pérez-Guisado and Jakeman, 2010) investigated the effect of citrulline supplementation vs placebo on the number of bench press repetitions to failure at 80% 1RM. The researchers tested the number of repetitions performed during 4 sets of flat barbell bench press both at the start and end of a pectoral (chest) focussed workout. This pectoral workout comprised of 16 sets in the following order: 4 sets of flat barbell bench presses (80% 1RM weight for the flat bench press), 4 sets of incline barbell bench presses (80% 1RM weight for the flat bench press), 4 sets of incline flys (60% 1RM weight for the flat bench press), and 4 sets of flat barbell bench presses (80% 1RM weight for the flat bench press) (Pérez-Guisado and Jakeman, 2010). Each tested set was performed to muscular failure.

The results showed citrulline supplementation increases the number of repetitions performed to failure over multiple sets when compared with a placebo. This effect is even greater towards the end of the workout when fatigue is at its highest. Put simply, citrulline supplementation allows you to perform more repetitions of the same weight compared to not supplementing with citrulline. This, in turn, promotes a greater hypertrophy stimulus for muscle gains, which is a common goal of the average gymgoer. 



Vitamin D is a fat-soluble micronutrient which is essential for human survival.

Although it can be obtained from dietary sources, such as milk, fish and eggs, intakes are often insufficient to meet daily requirements. The sun is also a natural source of vitamin D because the body can produce it from cholesterol using UV-light. However, this is only possible when the UV index is 3 which, in the UK, occurs between March and October and is only year-round near the equator. As a result, many individuals are either deficient or have sub-optimal levels.

Vitamin D is essential for maintaining strong, healthy bones by allowing effective calcium absorption within the body. Without it, adults develop a condition called ‘Osteomalacia’ which results in weak, brittle bones. However, this is not the only negative implication of low Vitamin D levels. Insufficient Vitamin-D levels are linked to several physical and psychological health issues such as:

  • Increased risk of developing heart disease (Wang et al., 2008)
  • Decreased athletic performance (Cannell et al., 2009)
  • Increased risk of illness and injury among athletes (Halliday et al., 2011)

Supplementing with Vitamin D is an effective way to improve body levels. This is why our PRE-CHU’s contain 5mg (200IU) per full dose (10) of gummies, which provides 50% of the recommended daily amounts by Public Health England. 


How can we guarantee CHU’s are safe?

PRE-CHU’s are manufactured in a pharmaceutical grade facility which is regularly tested for prohibited substances. This means no surprises. What you see on the pack is exactly what’s in the pack!

So why not ditch the shaker, upgrade your workouts and give PRE-CHU’s a try?



Cannell, J. J., Hollis, B. W., Sorenson, M. B., Taft, T. N. and Anderson, J. J. (2009) 'Athletic performance and vitamin D', Med Sci Sports Exerc, 41(5), pp. 1102-10.

Cook, C., Beaven, C. M., Kilduff, L. P. and Drawer, S. (2012) 'Acute caffeine ingestion's increase of voluntarily chosen resistance-training load after limited sleep', Int J Sport Nutr Exerc Metab, 22(3), pp. 157-64.

Duncan, M. J. and Oxford, S. W. (2011) 'The effect of caffeine ingestion on mood state and bench press performance to failure', J Strength Cond Res, 25(1), pp. 178-85.

Graham, T. E. and Spriet, L. L. (1995) 'Metabolic, catecholamine, and exercise performance responses to various doses of caffeine', J Appl Physiol (1985), 78(3), pp. 867-74.

Halliday, T. M., Peterson, N. J., Thomas, J. J., Kleppinger, K., Hollis, B. W. and Larson-Meyer, D. E. (2011) 'Vitamin D status relative to diet, lifestyle, injury, and illness in college athletes', Med Sci Sports Exerc, 43(2), pp. 335-43.

Kern, B. D. and Robinson, T. L. (2011) 'Effects of β-alanine supplementation on performance and body composition in collegiate wrestlers and football players', J Strength Cond Res, 25(7), pp. 1804-15.

Krzysztofik, M., Wilk, M., Wojdała, G. and Gołaś, A. (2019) 'Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods', Int J Environ Res Public Health, 16(24).

Paton, C. D., Lowe, T. and Irvine, A. (2010) 'Caffeinated chewing gum increases repeated sprint performance and augments increases in testosterone in competitive cyclists', Eur J Appl Physiol, 110(6), pp. 1243-50.

Pérez-Guisado, J. and Jakeman, P. M. (2010) 'Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness', J Strength Cond Res, 24(5), pp. 1215-22.

Stout, J. R., Cramer, J. T., Zoeller, R. F., Torok, D., Costa, P., Hoffman, J. R., Harris, R. C. and O'Kroy, J. (2007) 'Effects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women', Amino Acids, 32(3), pp. 381-6.

Wang, T. J., Pencina, M. J., Booth, S. L., Jacques, P. F., Ingelsson, E., Lanier, K., Benjamin, E. J., D'Agostino, R. B., Wolf, M. and Vasan, R. S. (2008) 'Vitamin D deficiency and risk of cardiovascular disease', Circulation, 117(4), pp. 503-11.