Chapter 14 - Nutrition for Recovery Flashcards
3 Rs of Recovery
rehydrate, refuel, and repair
recovery vs adaptation
It is important to understand that a recovery strategy may differ depending on whether rapid recovery or training adaptation is the goal. The purpose of a training session is to bring about an adaptation, while the objective in a competitive event with multiple heats and/or multiple days of competition is to perform maximally to win, which requires optimal recovery between contests
In differentiating between recovery and adaptation, the fitness professional can maximize what they want to achieve with an athlete between sessions, demonstrating an interconnected, periodized approach.
what is your body’s response to exiting a state of euhydration?
- retaining water in the kidneys
- thirst to prompt rehydration
hyperthermia
Abnormally high body temperature caused by a thermoregulation failure
thermoregulation
The ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different
heat stress
Includes a series of conditions where the body is under stress from overheating; heat-related illnesses include
* heat cramps
* heat exhaustion
* heat rash
* heat stroke
each with its own symptoms and treatments; symptoms can range from profuse sweating to dizziness, cessation of sweating, and collapse
methods for monitoring hydration status
- Pre- and post-session weigh-in
- Measurement of urine osmolality (if osmometer is available)
- Subjective assessment of urine color
methods for monitoring hydration status
Pre- and Post-Session Weigh-In
weigh-in pre- and post-training session or competition. Mass balance is the simplest and most accurate method to determine sweat rate
Acute body mass change represents 1 mL of water (sweat) loss per 1 g of body mass loss
methods for monitoring hydration status
Measurement of Urine Osmolality
Urine osmolality is the number of molecules per kilogram of water. Salt (sodium chloride) and urea account for most of the osmotic activity in the urine
The more concentrated the urine is with molecules of salt and urea, the more dehydrated a person is
mOsmol
In the relatively dilute fluids in the body, the osmolality is measured in milliosmoles (one thousandth of an osmole) per kilogram of water (mOsmol/kg); osmolarity is similar but is defined as the number of osmoles (or mOsmol) per liter of solvent.
methods for monitoring hydration status
Subjective Assessment of Urine Color
methods for monitoring hydration status
sweat and electrolyte testing
Sweating rate (SR) and sweat electrolyte concentrations can vary considerably among athletes due to individual and environmental factors. If a more advanced, personalized approach to determining athlete SR and electrolyte loss is required, a trained physiologist can assist with further testing
practical rehydration strategies
A key principle is to ensure that fluid intake is 1.5x (in liters) the loss in body mass induced by exercise
if an athlete weighs in at 70 kg (154 lbs) in a semi-nude state before the session and then weighs in at 69 kg (152 lbs) in the same state post-session, they should consume 1.5 L of fluids to replace the fluid lost.
short-term rehydration
Immediately after exercise, drinks that include sugar and salt will help rehydrate, replace lost sodium, and replace carbohydrate stores. Good candidates are chocolate milk, sports drinks, or smoothies. Dried and fresh fruits also provide water and carbohydrates
long-term rehydration
mineral waters, soups, and milk are good choices to rehydrate and maintain a euhydrated state. Fruits and vegetables with high water content will also help to maintain euhydration.
Examples include broccoli (91% water), grapefruit (91% water), lettuce (96% water), pineapple (87% water), tomatoes (94% water), strawberries (92% water), celery (95% water), and cucumbers (96% water).
hyponatremia
Low sodium concentration in the blood.
Key signs and outcomes of hyponatremia include:
Weight gain at the end of the race
Concentration of sodium in plasma (<130 mmol/L or <130 mg/dL)
Nausea and vomiting
Headache
Confusion
Muscle weakness
Coma
refueling
restoring the depleted carbohydrate pool in both muscle and the liver, especially if another training session is scheduled for later in the day, is critical
During the post-exercise period, muscle cells demonstrate a heightened sensitivity and ability to store ingested carbohydrate. Thus, the rate at which glycogen can be replaced is much greater during the initial hours of recovery (Piehl, 1974). Following the initial, rapid phase of glycogen resynthesis, resynthesis rates decrease to approximately 20% of the initial phase and can last up to 48 hours
amount of carbohydraet intake after exercise
1.2 g/kg BM per hour further enhances rates of glycogen**
To put carbohydrate refueling in context, a 70 kg (154 lb) athlete would require approximately 85 g carbohydrate per hour to maximize the rate at which glycogen is restored within the muscle.
Carbohydrate Type
The type of carbohydrate consumed can have a significant impact on glycogen resynthesis rates
consuming carbohydrates with a high glycemic index can speed up the rate of glycogen resynthesis within the initial hours post-workout when compared with lower glycemic index foods. Furthermore, because the glucose transporter in the gut is limited to carrying no more than 60 g of carbohydrate across the cell membrane, using multiple sugar sources is recommended
liquid carbohydrate sources
Athletes may prefer to ingest liquid sources of carbohydrate during the first hour of recovery, because appetite is commonly suppressed during this period. Choices in this period could include chocolate milk, sports drinks, or smoothies, all of which would also serve to help rehydrate.
what does exercise do to the body with regard to carbohydrate?
After exercise, blood flow to skeletal muscle is enhanced and there is a heightened sensitivity to available nutrients
Thus, the immediate provision of carbohydrate enhances the rate at which glycogen is resynthesized within the initial hours following exercise when compared with delaying carbohydrate by as little as two hours
Following the initial, rapid phase of glycogen resynthesis, resynthesis rates can decrease at what percent?
20%
repeated bout effect
Refers to the adaptation whereby a single bout of eccentric exercise protects against muscle damage from subsequent eccentric bouts.
nutrition for physiological repair
Skeletal muscle mass is maintained by a constant turnover of its proteins through synthesis and degradation. When synthesis rates decline or degradation increases such that muscle proteins degraded quicker than they are synthesized, muscle mass is lost.
Nutrition plays a key role in activating and sustaining the production of new muscle proteins, and exercise appears to sensitize muscle to amino acid feeding
