Enter your keyword


Should you restrict carbohydrates before exercise?

by K.N.*

Contemplating about pre-fueling methods?

Is this you? Are you into recreational sports, with some aspiring goals to do well in local endurance events? Do you often restrict carbohydrates, getting long sessions in, hydrating when- ever you remember, or following a plan? Do you see something familiar here?

Well, a few of the things that you need to pay attn to are, on top of how you structure your training hours, is how to fuel those session and when. Restricting carbohydrates before a workout that has high demands, is going to yield limited success as to the metrics you monitor.  We know clearly that demanding, high intensity efforts, over 15-20’’ in duration are highly glycolytic (require glucose in order to occur), and require that type of fuel to be readily available. Deprive your body of that fuel, and your expectations need to be reduced as well. High-end efforts are “expensive” in fuel, and need proper planning to ensure that the muscles (specific muscle fiber types) are able to deliver “winning level” force through muscular contractions.

However, if you are getting out there, with a low intensity (low effort workout) you “might” get by with carbohydrate restrictions prior to the start of the session. The key word,‘’might’’, needs attention, since the duration of your training session will determine if you hit the wall or not. Fuel, either we like it or not might be one out of the ‘’ two pillars supporting your structure’’. Remove fuel and you go nowhere. The other highly important pillar that supports your training session is quality sleep. Deprive your body of sleep for just one evening, and your physiology will demonstrate that you are doomed to fail.

Having a pre-exercise fueling strategy, starts with some basic planning.

It is worth mentioning though that low intensity efforts that rely on the aerobic mechanism, and demand no peak efforts present, can be sustained if you gradually introduce this training method of carbohydrate restriction prior to start. The beginning phase of this trial will feel quite tough on your physiology and psychology of course due to the fasted state.  Start with short, low intensity training sessions using this method of carbohydrate restriction and work your way to longer sessions according to feel. This fasted mechanism will take months to become optimized, and the moment you raise the notch to achieve peak efforts, (or near-maximal muscular contractions using fast twitch muscle fibers) you will feel the disastrous state of bonking.

 On a health index point of view, restricting carbohydrates, or calories in general, and going on with your light daily routine, (no major physical activity present), your body will see benefits that the nomenclature agrees on. However, do plan your pre-fueling strategy in conjunction with your physical activity plan of the day. This strategy should have your nutritionist involved to jointly make the decision for weight management and fueling.

Plan with what the scientific literature has to offer, and you are a step closer to success.


*Kypros Nicolaou, M.A., B.Sc., is an Exercise Physiologist, graduate of the University of Alabama, an ACSM certified Health & Fitness Instructor, holds an ITU  Level II Certification as a Triathlon Coach, and is a multiple Ironman & Half Ironman Triathlon finisher. He is coaching Triathletes & runners online, teaches Functional Training at ryltoday studio / Nicosia, and performs Exercise Physiology assessments at the Cyprus Sports & Research Center. www.ryltoday.com

No Comments

Leave a Reply