The following is an excerpt from Scientific Foundations and Practical Applications of Periodization With HKPropel Access by G. Gregory Haff.
An athlete’s ability to recover from training is affected by numerous controllable and uncontrollable factors (figure 9.2, page 202). One of the most important factors to consider is the structure of the periodized training plan. The coach should consider the effect of the athlete’s age and training status, as well as how nutrition (see chapter 10) affects the recovery process. Additionally, due to the increased amount of travel during competition periods, the coach must also consider how travel, fatigue, and recovery are related.
Age
An athlete’s age influences their ability to adapt to the training process (89, 238). It is widely believed that older athletes require longer recovery periods after training than their younger counterparts. Support for this belief can be partially explained by the slower rate of recovery of older athletes after exercise that contains large amounts of eccentric muscle actions (66, 161) that stimulate greater amounts of muscle damage (161, 242). In fact, older athletes tend to have longer recovery times after eccentric exercise (66, 242). These delays can be manifested as a longer time period before neuromuscular performance recovers (27), which may increase their overall risk of injury. Overall, older athletes appear to be at a greater risk of sustaining an injury than their younger counterparts (238). In addition to these slower recovery rates, older athletes also display an increased perception of muscle soreness and fatigue, which can affect their willingness to train (27).
Older athletes take longer to recover from intense exercise than younger athletes (204). For example, Taylor and colleagues (283) report that children require about half the recovery time of adults. Similarly, Ratel and colleagues (221) report that during 10 consecutive maximal cycle sprints, children can maintain power output with 30-second recovery intervals, whereas adults required 5-minute intervals. Based on these data, age does affect recovery rates. Therefore, when constructing training interventions, the coach must consider the age of their athletes and how age affects the athlete’s ability to recover from the prescribed training. This consideration is simply another logical step in the individualization of training at the center of training theory.
Training Status
It is important to consider the athlete’s training status when examining how rapidly an athlete recovers from training. As noted in chapter 1 (figure 1.8, page 9), training loads that are effective for novice athletes would result in detraining if they were applied to advanced athletes (330). As athletes become more trained, they require greater training loads and variation in training stimulus to increase performance. Therefore, the coach must introduce unloading periods to induce recovery from particularly hard training sessions, microcycles, or mesocycles. Additionally, it may be warranted to align specific recovery interventions during periods of intensive training.
One factor often overlooked is the effect of muscular strength on an athlete’s ability to recover from training and competition. Athletes exposed to spikes in training load, often as part of a shock microcycle or session, have an increased risk of sustaining an injury (92). Interestingly, this increased risk is significantly reduced when stronger athletes are exposed to these types of microcycles or sessions (170). In addition to strength, well-developed physical capacities also seem to reduce injury risk (90). One reason for these findings is that stronger, more physically fit athletes generally display a faster rate of recovery from high-intensity training sessions when compared to weaker athletes (132, 255). Incorporating training activities that enhance maximal strength and overall fitness is essential for enhancing the athlete’s ability to recover from training and competition stressors.
Travel Considerations
Travel is common in many athletes’ annual training plans (110). In fact, athletes often undertake long-haul, transmeridian travel to compete in world championships, the Olympic Games, and league or tournament play (110, 130). Athletes are at risk of travel fatigue when exposed to frequent travel (130). If the athlete’s travel requires them to cross multiple time zones, a desynchronization between the body’s circadian rhythms and the external 24-hour light–dark cycle can occur (110), resulting in jet lag (245).
The magnitude of jet lag is largely affected by the number of time zones crossed and the direction of travel (50). Symptoms of jet lag, such as disturbed sleep patterns, daytime fatigue, reduced alertness, decreased mental and physical performance capacity, gastrointestinal disruptions, and headaches can occur when an athlete undertakes travel across multiple time zones (greater than 3) (50, 130). Many of these symptoms can be resolved at a rate of 1 day per time zone crossed (245), but in some instances if the change in time zone is greater than 8 hours, these symptoms can persist for as long as 1 week (50). Additionally, eastward travel tends to result in a greater degree of jet lag, which extends recovery time compared to westward travel. Although the effect of jet lag is episodic, frequent exposure to jet lag during a competitive season can result in travel fatigue (50, 245). Samuels (245) proposed a conceptual model that differentiates between jet lag and travel fatigue, taking into account travel direction, number of time zones crossed, travel frequency, and the length of the athlete’s competitive season (figure 9.15).
Adapted from Samuels (2012).
In this model, the concept of the time-zone differential, which accounts for circadian factors related to time of day and circadian resynchronization (264, 265), was introduced to explain how the effects of travel direction and distance translate into the episodic occurrences of jet lag (245). Additionally, the model also introduced the concept of travel fatigue and how it is affected by the recovery window, which accounts for the available recovery time and modulates the effects of travel distance and frequency and their effect on cumulative fatigue across a competitive season (245).
The athlete’s response to travel is highly individualized and can be affected by several additional factors (310). For example, younger and fitter individuals who have flexible sleeping habits seem to better handle travel difficulties (310). Additionally, an individual’s chronotype seems to affect how they handle travel. For example, morning types (i.e., larks) are better able to adjust to eastward travel when compared to evening types (i.e., owls) (310) who are better able to handle westward travel.
Many strategies can be employed to help the athlete cope with travel (figure 9.16). Generally, these strategies are broken into three phases: pretravel, during travel, and posttravel (245).
Pretravel
If the athlete’s competition schedule allows, they can begin implementing pretravel strategies about 7 days prior to departure. For example, a team can adjust its training schedule to facilitate recovery prior to travel. If traveling eastward, plan an evening flight. If travel requires going across 10 or more time zones, schedule layovers (227, 245, 310). Another strategy is to preadjust to the time zone to be visited by going to bed 1 hour earlier each night before traveling east or 1 hour later each night before traveling west.
During Travel
When flying, the athlete should employ strategies that facilitate recovery and help them tolerate the process of traveling. One strategy often recommended is to have the athlete adjust their watch or smartphone to the layover or destination time zone as soon as they get on the plane (245). To facilitate rest and relaxation, the athlete should consider bringing eye shades and ear plugs or noise-cancelling listening devices to decrease overstimulation (245). While traveling, the athlete should avoid large meals, caffeine, and alcohol (110). Athletes should focus on maintaining hydration via water consumption and avoid boredom eating (110, 245). Finally, sleep should be aligned with the destination schedule (245).
Posttravel
The posttravel period lasts 2 to 4 days after arrival (245). During this time, the coach must strategically plan meals, sleep, rest, recovery, and training to accommodate a rapid adjustment of the circadian rhythms to the destination’s time zone. Athletes should avoid alcohol consumption and long naps and strive to create regular sleep and eating schedules. When necessary, athletes can take short power naps of less than 20 minutes (24).
G. Gregory Haff, PhD, CSCS,*D, FNSCA, is a professor of strength and conditioning and the course coordinator for the postgraduate degree in strength and conditioning at Edith Cowan University in Joondalup, Australia. He has published more than 240 articles, centering his research on performance effects in the areas of strength-training methodologies, performance testing, training theory, and nutritional supplementation.
