We've had 20 weeks out of the pool. This has never happened to a group of swimmers in my lifetime so returning to the pool calls for special thought on how we build swimmers back up again - push too hard too soon and they'll get injured, but go too slowly and they'll not get back to where they should be any time soon. In the past I've helped swimmers who have, as individuals, had time out of the pool due to injury/illness etc. but never have I had to nurse over 20 swimmers back to fitness at the same time. I think it's fair to say that not many other coaches have had to do that either. When I've done it for individuals I've done it largely using feel and experience and I've never really had a problem but this situation is a whole different kettle of fish.
Thankfully, the geniuses at Science for Sport have come up with a system that sounds perfect for what we need which they've named the 'Acute:Chronic Workload Ratio'. It sounds complicated but thankfully, it's not and my squad will be using it. "How's it work?" I hear you ask...
At the end of each session I'll ask each swimmer for a number between 1 and 10 for how hard they felt they've worked overall that session (this is known as the Rate of Perceived Exersion score or RPE for short). This number will get logged down next to the number of minutes that swimmer swam for. This will then go into a spreadsheet:
At the end of the week I'll multiply the number of minutes by RPE for each day and add the numbers together to get an 'Acute Workload' score for each swimmer for that week. At this point the table will look more like this:
|("A Swimmer's" Acute Workload score is 990 for this week because (40 x 6) + (50 x 6) + (50 x 4) + (50 x 5) = 990)|
I'll then keep this up, making a conscious effort to not overdo it and review after 4 weeks. At this point we'll have 4 weeks worth of 'Acute Workload' scores which we can use to calculate 'Chronic workload' scores from. The Chronic Workload score is equal to the total of the previous 4 Acute Workload scores added together and then divided by 4. At this point the table will look something like this (with unneccessary columns hidden):
|Swimmer's Name||WEEK 1||WEEK 2||WEEK 3||WEEK 4||4 WEEKS|
|Acute Workload||Acute Workload||Acute Workload||Acute Workload||Chronic Workload||Acute:Chronic Workload Ratio|
|("A Swimmer's" Chronic Workload score is 991.25 because (990 + 940 + 1045 + 990) / 4) = 991.25)|
|("A Swimmer's" Acute:Chronic Workload Ratio 1.05 because 1045/991.25 = 1.05422...)|
The Acute:Chronic Workload Ratio is simply the comparison of the last 'Acute Workload' score with the 'Chronic Workload' score. Science for Sport state the following regarding Acute:Chronic Workload ratio:
- < 0.8 = Under training and higher relative injury risk
- 0.8 to 1.3 = Optimal workload and lowest relative injury risk a.k.a "The Sweet Spot"
- > 1.5 = The “danger zone” and highest relative injury risk
We'll aim to sit somewhere in that 0.8 - 1.3 zone.
Once the initial 4 weeks are up, I'll then do a weekly comparison between that week's Acute Workload score and the latest Chronic Workload score so that I can easily monitor if anyone is over/under doing it. The latest Chronic Workload score will also be calculated each week based on the 4 most recent Acute Workload Scores.
I hope that helps/makes sense/explains things okay. I wish all coaches and swimmers a very safe return to training, it's certainly going to take some time to build back up properly and a system like the one above will definitely help.