How to Scale Training After a Break
Training workload (TW) is always a tricky variable to figure out. Admittedly, most sports performance professionals struggle with that issue almost as much as sport coaches and parents. One important thing to keep in mind when trying to figure out your optimal TW is how your TW this week compares to TW in recent weeks.
First, if you’re stuck on the term ‘training workload’ think of it as intensity x volume. One simple example of this would be using heart rate and time to calculate TW. If you went for a run you could calculate your TW by multiplying your average heart rate during that run by the number of minutes you ran for. If you ran for 10 minutes and your average heart rate was 120 beats per minute, you could say that your TW was 1200 arbitrary units. This is also known as a training impulse (TRIMP) score. If you have a heart rate monitor you could also use the calorie count as a measure of your training workload. You could also ballpark your intensity of any giving bout of exercise using a 1-10 scale or even the categories light, moderate and hard. In short, you do not need sophisticated equipment to figure out your TW.
One common mistake sport coaches and athletes make after periods of extended rest (eg. Christmas break, Summer break, exams break, etc.) is trying to make up for lost time in the first days back. Coaches and athletes commonly start new training blocks after extended periods of rest by increasing the training load above what it previously was. The mindset is that the athletes are well rested, so they should be ready for heavy workloads and that they need to ‘get the rust off’ and get back into shape.
This is kind of like trying to take a sip of water from a fire hose and it is potentially a recipe for disaster. Researchers have shown that increasing workload by more than 15% in one week can increase injury risk between 20% and 50%. If athletes do little or no training for a week or two during transition phases in their schedule, then go back to higher TW than they were previously undertaking, they are surpassing the suggestion <15% increase in TW in one week.
Additionally, researchers have discovered that another very strong predictor of injury is an athlete’s acute:chronic workload ratio (ACWR). Acute workload is represented by the total TW over the previous week and chronic workload is represented by the total TW over the previous 4 weeks. When you divide last week’s workload by the average of the previous four week’s workload you get an ACWR score. When this number is between 0.8 and 1.3 the athlete is in the sweet spot. When the ACWR gets above or below that range, we run into trouble. Athletes who have an ACWR greater than 1.5 have a 2-4x greater chance of being injured than those in the ACWR sweet spot.
In summary, rest is good but to avoid undue injury it is imperative that training intensity and volume ramps back up progressively after periods of extended rest. The first week back to training should be done at a moderate TW in order to properly manage the athletes ACWR and avoid a larger than desired spike in TW from the previous week.
Gabbett, T. J. (2012). The training-injury prevention paradox: shoulder athletes be training smarter are harder? British Journal of Sports Medicine, 50, 273-280.