Chapter 18 - Fuel for the Work Required Concept Flashcards
fuel for the work required concept
allows for total energy and carbohydrate intake to be altered on a day-by-day basis as determined by the demands of the specific training being completed. In this way, daily carbohydrate requirements are dictated by the duration and intensity of exercise being performed using a sliding scale approach
what type of athletes is the “fuel for the work required” approach suited for?
primarily suited for athletes who already have a well-structured nutrition program, and so, this strategy forms the final layer of nutritional strategies to allow the Sports Nutrition Coach to offer a truly customized program. The relevance of the “fuel for the work required” model will also depend on the athlete’s training schedule and the variability in energetic demand between each session
what 3 goals does the “fuel for the work required” concept achieve?
- Meet daily energy requirements
- Maintain muscle glycogen stores to ensure adequate fuel availability
- Amplify the training response
Meet daily energy requirements
triathlete example of “fuel for the work required” concept
perform 3 to 4 different types of training each week, with some sessions lasting less than an hour and others lasting from of 4–5 hours. In addition to this, some sessions will be performed at a relatively low intensity, which is typical of longer duration sessions, while others will be performed at maximal intensities, which is more typical of short-duration, repeated, sprint-type sessions.
maintain muscle glycogen stores
Because the majority of athletes train and compete on consecutive days, they frequently experience day-to-day fluctuations in muscle glycogen
Repetitive daily training can lead to progressive reductions in muscle glycogen concentrations if carbohydrate intake is insufficient and is not adjusted according to the demands of the session. This clearly has implications for training performances, because gradual reductions in muscle glycogen are likely to impair overall training intensity and, in some cases, may lead to a de-training effect
can you overshoot glycogen stores?
yes
Maximizing glycogen stores for each training session is unnecessary as long as the athlete has sufficient glycogen available to meet the demands of each session. It is also important to remember that excess glycogen will also increase water retention and may actually negatively impact performance by increasing the athlete’s weight.
amplifying the training response
The goal of all training is to create metabolic stress within the muscle. This metabolic stress provides the initial signal that ultimately causes the muscle to adapt through the activation of a complex network of molecular events.
examples of training responses
The contraction of skeletal muscle as we exercise results in a number of disruptions within the body. These include the release of calcium from the sarcoplasmic reticulum, increased breakdown of ATP, reductions in muscle glycogen, and accumulation of lactate. These events play an important role in activating various proteins that influence how our muscle adapts to the training stimulus. Once activated, these proteins are able to influence the activity of specific genes that dictate the adaptations that occur as a result of training. For example, endurance exercise activates genes that are responsible for the synthesis of mitochondrial proteins that play an important role in energy production. In contrast, resistance exercise activates genes that control muscle growth. Ultimately, the goal of exercise is to activate these molecular signaling proteins that govern the activity of key genes involved in training adaptation.
scenarios suited to low-glycogen training
- Off-season or base preparation training sessions
- Athletes who require endurance training adaptations (e.g., marathon runners)
- Highly trained athletes who have already maximized the training response through increases in exercise intensity and duration.
