Ever lose focus during an important situation and can’t figure out why? Maybe in a meeting at work. Or maybe it’s trying to read a putt on the 16th green.

Turns out, Glucose levels have a dramatic impact on your mental sharpness and ability to stay focused. Here’s how you can stay on top of them and keep your clarity:

  1. Avoid steep glucose spikes throughout the day.
  2. Maintain high enough glucose during your workouts.
  3. Improve your glucose control to help your focus, memory, and overall energy.

We’ve all had that feeling of the post-lunch lull. It’s probably worse after a carbohydrate heavy meal and that subsequent crash in energy levels. While there are a myriad of things in our modern lifestyle that may be driving this, glucose levels certainly play a key role.

Part of the reason? Your brain’s primary fuel is glucose. This is apparent when looking into fuel usage with differing activities. Research suggests that demanding mental tasks are improved following a glucose load as compared with a placebo.(Donohoe et al, 1999. Kennedy et al, 2000)  Perfect example: memorization. A demanding activity that’s hindered by low glucose levels.(Scholey et al, 2006) Turns out, blood glucose level decreases more rapidly while performing a more demanding mental task as compared with an easier one. Similarly, a period of intense cognitive processing leads to a measurable decrease in levels of peripherally measured glucose.(Donohoe et al, 1999. Kennedy et al, 2000)

Here’s another thing: The threshold for impairment of cognition seems to be variable, but the range is reported as 36-50mg/dL, though some individuals had no performance impairment at 36mg/dL and others showed impaired performance already around 72mg/dL.(Widom et al, 1990) There is a suggestion that cognitive disruption occurs at higher glucose levels in non-diabetic individuals whose symptoms of hypoglycemia are relieved by food.(Snorgaard et al, 1991)

The impact of focus and glucose extends well beyond the realms of the brain and into how our brain and body interact. While the research is still in its infancy, there is good indication that low glucose can impact skill execution in many different contexts. Let’s take a look at a few scenarios:

General Sports

Unsurprisingly, there is research indicating improved performance in the second half of simulated intermittent high intensity games across speed, agility, and motor skill tasks, as well as perception of fatigue, when supplementing with carbohydrates compared to not consuming any carbohydrates.(Welsh et al, 2002)

Football (Soccer)

It seems that the most consistent results regarding carbohydrates’ effect on skill performance can be found in the soccer literature. Most studies have reported improvements in players’ shooting, dribbling, and/or passing performance with ingestion of a 6–8% carbohydrate solution at an intake rate of 30–63g/h.(Baker et al, 2015) These effects do not seem to manifest in the absence of fatigue, pointing to the role of fuel (glucose) especially in key moments of a match like toward the end where players are more likely to commit mistakes due to fatigue.

Cycling

Evidence that hypoglycemia impaired neuromuscular performance (evaluated by sustained maximal voluntary contraction) in cyclists gives indication that the hypoglycemia is the driving factor in this when taken in conjunction with the fact that central nervous system functionalities  appears unimpacted by three hours of moderately intense exercise in trained athletes if normal glucose is maintained.(Nybo et al, 2003)

Tennis and other Court Sports:

Similarly indicative evidence exists across both tennis and squash when it comes to skill execution across sports specific skills such as first serve percentage and return success. The research in squash looked at glucose levels and markers of exhaustion (such as lactate levels) and found glucose to be maintained by carbohydrate supplementation vs. a placebo. It also showed how this positively impacted glucose levels and skills while not impacting markers of exhaustion.(McRae et al, 2012)

Likewise, in a study looking at elite level fencing and squash athletes, ingestion of carbohydrate before exercise improved peak power output, decreased muscular tiredness, and sped up both information processing and visual detection without changing accuracy.(McRae et al, 2012)

Take home message:

A constant challenge for all of us in the modern world is understanding the genesis of those seemingly random feelings of lack of focus or overall lack of energy especially around exercise.

Until we had access to continuous glucose monitoring, it was hard to understand why we were a bit mentally fuzzy throughout the day or during a workout. Well, the guessing game is over in this context.

Now, we can proactively avoid steep spikes that can cause metabolic imbalance and subsequent steep drops that might lead to poor feelings. In a workout, we can see when we are low in glucose and make informed nutrition decisions to stay well-fueled and cognitive ready.

Imagine a day where you are in control of your energy. Actually, don’t imagine it:  focus on your glucose and monitor it with Supersapiens, instead of focusing on why you can’t focus. A better use of your energy and time… every time.



References

  1. Donohoe RT & Benton D (1999) Declining blood glucose levels after a cognitively demanding task predict subsequent memory. Nutrition Neuroscience 2, 413–424. https://pubmed.ncbi.nlm.nih.gov/27416053/
  2. Kennedy DO & Scholey AB (2000) Glucose administration, heart rate and cognitive performance: effects of increasing mental effort. Psychopharmacology 149, 63–71. https://pubmed.ncbi.nlm.nih.gov/10789884/
  3. Scholey AB, Laing S, Kennedy DO. Blood glucose changes and memory: effects of manipulating emotionality and mental effort. Biol Psychol. 2006 Jan;71(1):12-9. doi: 10.1016/j.biopsycho.2005.02.003. PMID: 15885875. https://pubmed.ncbi.nlm.nih.gov/15885875/
  4. Barbara Widom, Donald C. Simonson. Glycemic Control and Neuropsychologic Function during Hypoglycemia in Patients with Insulin-Dependent Diabetes Mellitus. Ann Intern Med.1990;112:904-912. doi:10.7326/0003-4819-112-12-904  https://www.acpjournals.org/doi/10.7326/0003-4819-112-12-904
  5. SNORGAARD, O., LASSEN, L.H., ROSENFALCK, A.M. and BINDER, C. (1991), Glycaemic thresholds for hypoglycaemic symptoms, impairment of cognitive function, and release of counterregulatory hormones in subjects with functional hypoglycaemia. Journal of Internal Medicine, 229: 343-350. https://doi.org/10.1111/j.1365-2796.1991.tb00357.x
  6. Welsh RS, Davis JM, Burke JR, Williams HG. Carbohydrates and physical/mental performance during intermittent exercise to fatigue. Med Sci Sports Exerc. 2002 Apr;34(4):723-31. doi: 10.1097/00005768-200204000-00025. PMID: 11932585. https://pubmed.ncbi.nlm.nih.gov/11932585/
  7. Baker LB, Rollo I, Stein KW, Jeukendrup AE. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance. Nutrients. 2015 Jul 14;7(7):5733-63. doi: 10.3390/nu7075249. PMID: 26184303; PMCID: PMC4517026. https://pubmed.ncbi.nlm.nih.gov/26184303/
  8. Nybo L. CNS fatigue and prolonged exercise: effect of glucose supplementation. Med Sci Sports Exerc. 2003 Apr;35(4):589-94. doi: 10.1249/01.MSS.0000058433.85789.66. PMID: 12673141. https://pubmed.ncbi.nlm.nih.gov/12673141/
  9. McRae KA, Galloway SD. Carbohydrate-electrolyte drink ingestion and skill performance during and after 2 hr of indoor tennis match play. Int J Sport Nutr Exerc Metab. 2012 Feb;22(1):38-46. doi: 10.1123/ijsnem.22.1.38. PMID: 22248499. https://pubmed.ncbi.nlm.nih.gov/22248499/