I think factors vary here such as: 1) goals 2) type of training used 3) tolerance and individual body comp 4) Type of carbs used. 5) Time of training 6) competition 7) Timing of consumption 8) Etc
That last thing is something I didnt catch in the article and I didnt follow thru with reading the study but when was the consumption of carbs taken prior to and post the workouts performed. I have seen different timing levels produce different results. I went through a stack of Strength and Conditioning articles a while back. Here is the information I pulled from it:
Carbs, PT and Sports Performance:
Intro: Pre-Intra-Post Workout carbs and there effects on performance and recovery. Post wod (training or competition) carbs are invaluable to recover glycogen stores, maximize muscle net protein balance and help fuel other repair mechanisms. Glucose is the primary carb fuel for working muscle and its contribution to total energy increases relative to exercise intensity and decreases with prolonged duration secondary to waning muscle glycogen.
Muscle Glycogen and Blood Glucose:
The difference between the level of glucose in the arteries supplying skeletal muscles and in the veins that drain them is greater when the muscles are engaged in physical activity. Therefore, glucose uptake complements glycogen breakdown during exercise. Muscle glycogen levels tend to be 10 -25% higher in type II vs. type I muscle fibers and muscle glycogen levels can be increased with moderate to high intensity training (Given about 5 months of weight training). The total amount of muscle glycogen is approximately 300 ? 500g depending on an athlete?s gender, size and training status while liver glycogen stores range between 60 ? 120g.
Carb Ingestion BEFORE Exercise:
General daily recommendations for athletes are 8 ? 10 g of carbs per kilo of body mass daily or greater than/equal to 60% energy. Many athletes engage in carb loading (or glycogen super compensation) to maximize glycogen stores, a practice that involves very high-carb intake (>70% daily cal intake from carbs), reduced training, and/or cessation in the day leading to an endurance event or game. While the classic method of glycogen loading involved glycogen depletion with 1 or more strenuous exercise bouts and very low-carb intake for a couple of days, more recent studies suggest a similar degree of glycogen optimization by simply tapering and ceasing exercise and consuming a high-carb diet. One potential benefit to ingesting carbs in the hours prior to exercise would be to raise muscle glycogen levels prior to the onset of exercise. Sample study done consisting of eating a high-carb meal 4 hours before 105mins of exercise at 70% Vo2peak increased muscle glycogen levels by 42% at the onset of exercise and led to greater reliance on muscle glycogen and total carb during the exercise bout. Meanwhile, research efforts on the ingestion of carbs at or within 60 mins of exercise have yielded equivocal results with regard to performance.
Decrease in performance seen in participant given 70g of glucose 30mins prior to 80% Vo2peak yielding exhaustion. Meanwhile, several related studies of ingesting carbs within an hour of exercise have resulted in neither negative positive effect on performance. Furthermore, research on the type of carbs (high or low glycemic index) within in 1 hour prior to training has also led to equivocal findings. Regarding carb type, the ingestion of either high or low glycemic meal or water 45mins prior to cycling for 135mins did not alter glycogen utilization or performance. Same for ingestion high or low within 30mins.
Carb ingestion immediately prior (less than or about 5mins) to exercise can result in improvements, especially if an individual has not eaten for extended periods (e.g., overnight fast). Research supports the notion that during higher intensity exercise, which would last a shorter time (<1 hour), performance can be enhanced by ingesting carbs just a few mins prior to onset of exercise. However, added benefits are not likely from consuming additional carbs during the exercise bout.
Carbs DURING Exercise:
Carb consumption during exercise increases the availability of carbs to working muscle fibers, which can have a positive influence on endurance performance as well as intermittent high intensity performance, the latter of which could be applicable to sports such as football, ice hockey and soccer. Carb type is an important consideration as glucose, maltose, sucrose, amylopectin and matlodextrins are oxidized at higher rates than fructose, amylose and galactose.
Whether or not carb ingestion can slow the rate of muscle glycogen, breakdown remains debated. Regardless, carb ingestion during endurance exercise can extend performance time prior to fatigue.
Ingesting carbs, either in liquid or solid form shortly after training or competition, is crucial to maximizing muscle glycogen recovery. Timing is critical. If carbs are ingested within 30mins or so after exercise, enhanced glucose uptake occurs as a result of the increased GluT4 translocation during exercise. On the contrary, if carb delivery is delayed by 2 hours, the rate of glycogen recovery is slowed by 50%. A carb intake of 9-10g of carb per kilo per day is suggested for athletes who are completing intense exercise bouts on consecutive days.
The glycemic and insulinemic effect of different carbs is an important consideration. It?s reported that fructose is not an effective promoter of muscle glycogen recovery after glycogen-reducing exercise. This is attributable to its relatively low insulinemic effect and subsequent low glucose availability and uptake in skeletal muscle. Similarly, post-exercise ingestion of varying forms of starch has been shown to impact resynthesis of muscle glycogen but not resulting performance.
Higher glycemic index foods may allow for a more rapid glycogen recovery versus lower glycemic index foods. Meanwhile, the co-ingestion of carbs (4g/kg body mass) with caffeine (8mg/kg body mass) has been reported to result in a greater accumulation of glycogen during recovery from exhaustive exercise. The addition to protein to carb has also been reported to enhance muscle glycogen recovery. However, when a relatively high amount of carbs was provided after glycogen depletion exercise, additional protein did not further enhance glycogen recovery. Carbs have been reported to support protein and more specifically essential amino acids in net muscle protein synthesis largely by reducing post-training muscle protein breakdown, while carbs by themselves does very little to promote muscle protein synthesis but can offset changes in protein breakdown. It?s reported that if, indeed, carbs play a supporting role in muscle protein synthesis after training, it can be negated by ample protein intake.
- The general recommendation for carb intake among athletes is 6 ? 10g/kg body weight. For endurance athletes training aggressively or competing daily, a carb intake at the high end is better suited.
- Athletes need to experiment with timing and type of carb to identify what works best for them.
- General recommendation for carb intake 3-4hrs prior to exercise for an adult is 1-2g/kg or roughly 200-350g. This would be appropriate to raise glycogen stores at the onset of exercise and potentially enhance performance especially if there was an extended fasting period prior (e.g. sleep).
- Many athletes choose foods that they have tolerated well in the past and that have minimal indigestible material (e.g. fiber). This meal should be lower in fat to allow for optimal rate of emptying from the stomach and should provide fluids to optimize hydration status.
- During endurance exercise bouts, athletes should strive to ingest 30 ? 60g of carbs per hour of performance to maintain blood glucose levels and optimize glucose uptake and oxidation. This can be achieved by drinking 600 ? 1200 mL of a 6 ? 8% carb sport drink per hour.
- Immediately after training or competition it is recommended that athletes ingest at least 1.5g of carb per kilo of body weight.
- Ingesting 1.2g of carbs per kilo of body weight every 30mins over a 5 hr. period can promote maximal glycogen resynthesis.
- Maximal glycogen levels can be restored within 24hrs at dietary carb intake levels of 8 g of carb per kilo per day.
- Waiting to ingest carbs for a couple of hours after strenuous exercise will dramatically reduce the rate of glycogen recovery.
The timing seemed to play all the difference in performance. I tried this out at a 4 workout day crossfit comp and saw improvements in recovery and performance. I also felt better during the wods. I normally train fasted with BCAA supps. In competition I will up carbs and notice help as opposed to the days I try to tackle depleting wods without them. For most workouts pace is a big factor, the slower I move (lets say tempo training) the less carbs I will feel* like I need. If Im anything gets balistic more carbs feel* necessary.
Just one dudes opinion though. Timing of the carbs makes the game I feel.