By Fabio Comana MA, MS, NASM-CPT, CES & PES; ACE CPT & HC; NSCA CSCS; ACSM HFS, CISSN, Exercise Physiologist and Faculty Instructor – SDSU, UCSD & NASM
Looking for optimal exercise training results? What you do before and after could be just as important as the actual training itself. Discover where to focus pre-exercise efforts and what to consider for post-exercise recovery.
In 1854, Louis Pasteur was quoted as stating that ‘fortune favors the prepared mind.’ By that same token, one could argue that a properly prepared body leaves less potential for injury and a greater possibility for optimizing training outcomes. Yet, countless individuals continue to give little thought to their pre- and post-exercise regimens when it comes to exercise. To illustrate the breadth of what this entails, one only has to think to corrective exercise techniques; dynamic movement patterns; mindful breathing, mental preparation; and timing, type and quantity of nutrition and hydration before exercise. Then, think about the myriad of post-exercise strategies – nutrition and rehydration; regeneration of the bioenergetic pathways; neuromuscular, immune and hormonal recovery and adaptation; and the overall cognitive and emotional impact of the training bout. These are just some of the many examples that exist for individuals to add into their programs to maximize their training experiences and the attainment of goals. However, in this article we’ll only cover several of these topics in greater detail.
Some Pre-exercise Considerations
When contemplating preparation of the body before exercise, a more global prerequisite approach should always be adopted that examines appropriate levels of stability and mobility throughout the kinetic chain. This should be considered long before an exercise programs is even initiated, but also monitored before each training session. Movement efficiency (quality) can easily be self-evaluated for the more advanced via the primary movement patterns (e.g., bend-and-lift, push, pull, single-leg stands) and some form of feedback (e.g., mirrors, video) or via more structured and traditional methods like movement screens including NASM’s Overhead Squat which provides an effective means to identify movement compensations (1). A good percentage of movement dysfunction can then be resolved via techniques including NASM’s corrective exercise continuum – inhibit; lengthen; activate and integrate. Interestingly, in individuals for whom loaded exercise (endurance through maximal strength) or explosive exercise (power endurance through maximal power) is deemed appropriate, the consensus of thinking and practices over the past 10 years has shifted away from static stretching prior to exercise. The trend has now moved towards active and functional flexibility given how static stretching is believed to reduce strength and power output, and compromise sports performance (2 – 3).
- Active flexibility techniques generally rely upon the principle of reciprocal inhibition using modalities like active isolated stretching that recruits agonists and synergists to move body segments while subsequently elongating antagonists.
- Functional flexibility techniques by contrast, are typically more compound in nature and demand more precise control of rate, direction and magnitude of muscle elongation to more closely mimic the upcoming movement patterns.
Recently however, researchers have examined existing studies on the effects of static stretching upon exercise performance when conducted before exercise (4 – 6). In reviewing over 100 studies on this subject, several authors noted inconsistencies in the research given different factors in experimental design (e.g., methodology, population, randomization), but did draw some generalized conclusions on the effects of static stretching before exercise:
- Decrements in maximal strength performance were not apparent when the duration of the static stretch was held for less than 30 seconds.
- Majority of studies do not support decrements in power performance (e.g., jumping) when the duration of the static stretch was held for less than 45 seconds.
- Decrements in performance are more likely when the duration of static stretching equals or exceeds 60 seconds.
- In some sports where large ranges of motion are required, static stretching performed beforehand may actually improve performance.
So what is the takeaway here? It appears that some static stretching (shorter duration below 30 to 45 seconds) may not impede performance, so including some static stretching before exercise, especially for individuals where larger ranges of motion are needed, may not be a bad idea.
When planning your nutrition and hydration strategies, high-performance workouts that are becoming popularized today certainly demand high-octane fueling. The old adage of ‘you are what you eat’ does speak volumes of truth, but key strategies emphasizing nutrient type, timing and quantity, all consumed prior to exercise, can have a significant impact upon training. While the science of sports nutrition necessitates a significant investment of time and effort to achieve professional competency, key preparation highlights that can prove beneficial to a training session are outlined below.
- Pre-exercise Hydration Guidelines
- Hydration is perhaps the most overlooked and undervalued preparation strategy required for exercise. As the sensation of thirst in adults under age of 50 normally begins when a person reaches approximately one percent loss of body weight (e.g., 180 lbs. or 81.8 Kg man losing 1.8 lbs. or 0.82 Kg) and the fact that dehydrated states of two to three percent loss of body weight can negatively impact training performance, a general philosophy to hydrate aggressively before and during exercise and avoid losses exceeding two percent should be followed (7 – 9). Pre- and post-exercise weight differentials (voided) is an effective method for determining bodily fluid losses.
- Pre-exercise hydration begins with the ‘in-sight-in-mind’ strategy that helps promote conscious fluid (water preferably) consumption starting 24 hours prior to the event – this does not imply excessive water intake, but the practice of increasing normal fluid intakes.
- Two to three hours prior to exercise, consume 500 – 600 mL (17 – 20 oz.) of fluid (water preferably) (10). Although some pre-exercise snacks and meals do provide some fluid, this amount is marginal and probably inadequate to properly hydrate.
- Should the event include a warm-up phase (e.g., marathon, soccer game warm-up), then a pre-event ‘topping off’ is suggested to replace any potentially lost fuel, fluids and electrolytes lost to sweat. Consume 200 to 300 mL (7 – 10 oz.) of a sports drink with no more than an 8% carbohydrate solution for every 15 minutes of the warm-up (10). Solutions greater than 8% concentration can delay gastric emptying and the delivery of fluids and carbohydrates to the body. Calculate beverage concentration as follows:
- Beverage concentration = (solute quantity ÷ solvent volume) x 100
- For example, an 8 oz. (240 mL) serving with 14 grams of carbohydrates equals 5.8% concentration.
- Working in metric units: (14 g ÷ 240 mL) x 100 = 0.058 x 100 = 5.8%
- Your turn to practice – calculate the concentrations of the following beverages:
- 10g in an 8 oz. (240 mL) serving.
- 28g in a 12 oz. (360 mL) serving.
- Answers: 4.2%, 7.8%
- Pre-exercise Carbohydrate Guidelines
- Carbohydrate loading and pre-exercise carbohydrate meals do follow unique guidelines specific to endurance-type athletes, but have less or little relevance with more-moderate cardio or resistance training. For the average client who may only expend 275 – 300 calories in a session, a light, low-to-moderate glycemic load snack providing 75 – 150 calories, consumed one to two hours prior to exercise, may provide a needed energy boost if they have not eaten in the past three to four hours (11). Higher glycemic loads consumed too close to exercise elevate circulating levels of insulin, which inhibits the action of an enzyme called hormone-sensitive lipase (HSL) that is primarily responsible for mobilizing fats during exercise (12). This enzyme is critical to mobilizing fat stores during sustained endurance exercise.
- This pre-exercise snack generally comprises a 2-to-1 to 4-to-1 carbohydrate-to-protein ratio. For example, a 120 calorie snack following a 2-to-1 ratio would contain 20g of carbohydrates and 10g of protein.
- Pre-exercise Protein Guidelines
- Timing of protein feeding is critical to enhancing muscle recovery and growth. When active individuals were fed an amino acid (EAA)-carbohydrate (CHO) beverage consisting of six grams of EAA and 35 grams of a high-glycemic CHO (EAA-CHO) within 60 minutes of exercise versus individuals who consumed the EAA-CHO beverage within 30 – 45 minutes following resistance-training exercise (at 80% 1 Repetition Max), it was the dosage consumed before exercise the proved to be more effective in promoting muscle synthesis (13).
- When the same researchers examined the impact of 20g whey isolate protein (equivalent amount to 6 grams EAA) consumed immediately before, and immediately after a similar resistance-training bout, they found no significant differences in synthesis rates, thus concluded that while pre-feeding is more effective then post-feeding, it is the EAA-CHO combination taken before exercise that maximizes protein synthesis rates during early recovery (14).
- An EEA-CHO mixture compared against a plain EEA solution promotes greater insulin release that accelerates amino acid uptake into cells, while also potentially reducing muscle catabolism under insulin’s anabolic effect. It is important to this note that this high-glycemic CHO recommendation contradicts recommendations mentioned previously for mobilizing fat stores. This contradiction illustrates the difference in research between resistance-trained and endurance-trained individuals. So what is the takeaway from this research for exercise performance?
- For resistance exercise where post-exercise muscle synthesis is a priority, the EAA-CHO combination (high-glycemic) indicated above or 20g of a fast protein (e.g., whey isolate) consumed within 60 minutes of exercise appears to be an effective strategy.
- For endurance exercise where fat mobilization and muscle glycogen sustainability are a priority, a lower-glycemic load with or without protein consumed one to two hours before exercise appears to be an effective strategy.
- Six grams of essential amino acids can be obtained through many whole food choices as illustrated in table 1-1 below, but when one considers the volume of food, the caloric density, plus any potential insulin response, a commercially prepared sports drink or powder may prove more feasible (15).
Table 1-1: Quantity of Common Protein Sources Providing 6 Grams of EAA
|Egg whites||Equivalent to 3½ large eggs|
|Roasted chicken||2½ – 3 oz. (1 small chicken breast)|
|Grilled white fish (cod, halibut)||2 oz. (cooked)|
|Canned Tuna (packed in water, drained)||1½ – 2 oz. canned|
|Cooked lean ground beef, steak or pork chops||1½ – 2 oz.|
|Luncheon meet||2½ oz.|
|Regular, low-fat or skim milk||12 oz.|
|Plain or fruit-flavored yogurt (with non-fat milk)||8 oz.|
|Cheddar cheese||2 oz.|
|Cooked white pasta||2½ cups|
|Cooked white rice||3 cups|
|Plain bagels||Two x 3½” bagels|
|Wheat bread||6 slices (1 oz. slices)|
|Peanut butter||5 tbsp.|
|Soybeans (raw)||¾ – 1 cup|
Heart Rate Monitoring
Heart rate variance (HRV) is quickly gaining interest from athletes and coaches alike considering how it provides useful information pertaining the body’s current biological status (i.e., presence and recovery from stress). Measuring the interval difference between each heartbeat (R-R interval) rather than just heart rate provides valuable feedback on the dominance of the sympathetic nervous system – SNS (‘flight-or-fight’ – stressed) or parasympathetic nervous system – PNS (‘rest, recovery and repair). Greater R-R interval variance reflects greater PNS dominance and improved overall biological status of the body (16). Although an ECG/EKG tracing is still considered the most accurate means to measure R-R intervals, various wearable devices utilizing telemetry are now claiming to accurately measure this interval. A simpler methodology exists – simply relax, close your eyes and breathe normally for a full 30-seconds while at rest and monitor fluctuations in your heart rhythm as you breathe (it should slow down following expiration and accelerate with inspiration). Considering how passive ventilation (relaxed, at rest) is connected to the PNS through the vagal nerve (aka sinus breathing arrhythmias), more variance indicates a state of recovery whereas the absence of fluctuation (i.e., little R-R interval) implies greater SNS dominance and more stress (17). During exercise when the body falls under greater SNS control, little-to-no R-R interval fluctuations are expected, hence the need for measuring HRV at rest. For coaches and athletes, this information, measured first thing in the morning (rested states), helps with the planning of hard training days and necessary offload periods. Considering how resting heart rate (RHR) decreases over time as conditioning levels improve, any RHR increases (over a 7-10 day period) coupled with less HRV collectively point to a stressed and unrecovered body that may be in need of an offload or recovery workout.
Some Post-exercise Considerations
What some perceive as the immediate post-exercise window actually refers to the timeframe between the end of one training session and the preparation phase of the subsequent bout. This includes promoting continued protein synthesis three to four hours post-exercise when the body generally reverts back to protein degradation, and monitoring RHR and HRV the following day.
Cellular dehydration can negatively impact normal physiological function of cells, tissues, organs and systems. Following exercise, effective rehydration of both the extracellular fluid (e.g., fluid outside cells – blood stream, interstitial space) and intracellular fluid (i.e., fluid inside cells) is necessary to assist with recovery and adaptation (18). Outlined below are some key recommendations for fluids, carbohydrates and proteins to optimize recovery and maximize post-exercise adaptations.
- Post-exercise Hydration Guidelines (10,11,19-20)
- Fluid rehydration estimates range between 100 – 150% of the volume of fluid lost, with guidelines differing between whether the individual ingests water or a commercial sports drink, and the needs are estimated using pre- and post-exercise body weight differentials.
- Given the dilution effects upon blood concentration that occurs with water and not with sports drinks, more specific guidelines suggest:
- Consuming between 125 – 150% of fluid lost (i.e., lost body weight) if rehydrating with water.
- Consuming between 100 – 125% of fluid lost (i.e., lost body weight) if rehydrating with a commercial sports drink.
- The primary goal of rehydration is to expedite the time needed to re-establish total body water and fluid balance. Consequently, the stomach’s volume threshold (approximately 700 mL or 23.7 oz.) and normal gastric emptying rates (30 – 40 mL or 1.0 – 1.4 oz. per minute at rest / 1.8 – 2.5 L / hour or 60 – 74 oz. / hour) should be considered. As optimal gastric emptying rates occur by ingesting 150 – 300 mL (5.1 – 10 oz.) of fluid every 10 to 15 minutes, this may necessitate a timed dosing strategy for individuals requiring larger volumes of fluids.
- Post-exercise Carbohydrate Guidelines (21-26)
- The major post-exercise macronutrient recommendation for endurance athletes is replenishing glycogen stores. This is emphasized during the immediate post-exercise stage given the elevated activity levels of glycogen synthase, the primary enzyme that stimulates glycogen production. The need to restore glycogen is less relevant for moderate-intensity or resistance-trained exercisers as these workouts may only deplete glycogen stores by 36 – 39%.
- Muscle glycogen stores can normally be restored within 24 hours following a high-intensity, glycogen-depleting workout by consuming a normal balance of macronutrients. Individuals seeking more aggressive restoration rates, the most active period for replenishment occurs within the first few hours post-exercise – being most active in the first hour and progressively decreasing thereafter.
- To expedite muscle and liver glycogen replenishment, use glucose, which is absorbed more rapidly than fructose and delivered to cells at faster rates – glycogen re-synthesis rates from fructose are estimated to be 50% slower than from glucose sources.
- Carbohydrate quantity recommendations suggest 1.0 g of carbohydrates per kilogram of body weight (0.45 g / lb.) ingested within the first hour. This may need to be repeated at two hour intervals (i.e., every two hours) over the period of four to six hours for ultra-endurance athletes to ensure complete recovery of muscle and liver glycogen.
- Post-exercise Protein Guidelines (27-30)
- While resistance training stimulates protein synthesis during early recovery (i.e., first four hours), it also stimulates protein degradation thereafter as evidenced by increased markers of protein breakdown in blood and urine.
- Whey protein is a rich source of essential amino acids (e.g., BCAAs), and is easily digested and absorbed, whereas soy and especially casein (an insoluble protein) are digested and absorbed more slowly. Consequently, whey appears to be a preferred protein source to consume immediately before or after exercise, whereas casein is more desirable several hours following exercise where it can help maintain a positive nitrogen balance within the body. For example, during the first few hours post-exercise, whey can increase protein synthesis rates by 119% over casein, whereas seven hours post-exercise, levels of leucine (an essential amino acid and marker for protein synthesis) are higher from casein sources when taken at the same time, although whey contains almost 25% more leucine. This illustrates how casein may sustain a positive nitrogen balance long after exercise.
- Many studies agree that a threshold level of 20 grams appears to exist within the body in recovery, implying that quantities above that amount do not further increase protein synthesis rates in most individuals.
Lastly and perhaps the latest trend emerging in fitness is overall wellness and stress management. It is important to understand that stress is a non-specific response to any demand (stressor) that overcomes, or threatens to overcome, the body’s ability to maintain homeostasis (31, 32). Essentially, this means that regardless of the nature of the stressor (e.g., exercise, starvation, daily commute, work-related issues), the body perceives stress as a biological event and responds in essentially the same way. What differs is simply the magnitude of our response. Keep in mind however, that imposing various levels of stress upon the body is quite natural and critical to our survival as long as the body is afforded opportunities for recovery between stressors to restore its baseline (33). Unfortunately, we no longer live in a world where are bodies (by design) are exposed to intense, acute physiological bouts of stress (i.e., eat or be eaten; kill or be killed) with subsequent bouts of recovery.
Today, we live in a world with sustained bouts of moderate, psychological stress that never ceases. As mentioned previously, the body does not differentiate and the neural and hormonal responses are very similar. Much in the same way that cortisol can temporarily disrupt many homeostatic and anabolic functions during an intense bout for survival purposes, sustained stress prolongs these disruptions, which in turn can wipe away many of the positive outcomes associated with a good exercise and dietary plan. For example, the benefits associated with healthy eating and activity that promote positive changes within hormones (e.g., Human growth hormone, estrogen, testosterone, thyroid stimulating hormone, leptin, cholecystokinin); systems (immune response, brain function – hippocampus health and elevated levels of brain-derived neurotrophic factor) and events (e.g., aging and telomeres on our chromosomes) can essentially all be wiped away with sustained cortisol (33).
As fortune favors the prepared mind, so too does it favor the prepared body. As professionals, can we afford to ignore the importance of proper preparation and recovery, and overall management and monitoring of the body’s overall status? We make a significant investment of time, energy and resources to attaining positive goals, yet may often fall short by not attending to these two phases with the same level of diligence. Perhaps it is time to expand our philosophical approach of training beyond the confines of the traditional brick and mortar and into the daily lives of those we help and serve. Not only does this gain us more relevance and value, but it shifts the paradigm of our services from training to coaching. Think about it.