Tapering at the Youth Level
Of course, few of these factors apply when coaching a developmental group of young kids who may only swim just three to five hours per week, where practices focus far more on stroke development than on maximally stressing their muscles and cardiovascular system. That leaves a lot less opportunity—and need—to reduce yardage and intensity.
In this case, decreasing yardage "organically" is a wise decision. Rather than focus on reducing the yardage total, lengthen warm-ups and cooldowns, and include longer stroke-recovery sets at exacting efficiency levels between shorter, more focused racing-practice sets. The total yardage may change relatively little, but the proportion of fast versus easy swimming will change significantly.
Even more important, when coaching impressionable (and often distractible) young kids, do everything possible to improve attention and execution. On every practice, set and repeat—indeed every stroke and turn—emphasize that as the number of practice opportunities diminish, each becomes more precious in influencing how exciting your championship will be.
For the coach, this means the increased period of rest between sets is utilized just as much to restate the real reason we come to the pool—To Practice the Skills That Win Races—as for physical recovery. And those longer warm-ups and cooldowns should be choreographed by including tasks that sharpen small details like head position, seamless breathing, and how you transition from turns to swimming at each wall.
With the age and developmental level of these kids and the kind of training they do, mental sharpening will be the most important ingredient by far. Even as a middle-aged distance swimmer who must be ever mindful of restoration and avoiding overwork, I still prefer to think of what I do in the week or two prior to an important meet or race as "sharpening" rather than "tapering." That puts the emphasis on tuning up both mental and physical processes.
Toward that end, including creative visualization prior to practice is a great idea. As well, it should be helpful is to have each swimmer express an intention prior to the start of practice. That intention could be behavior-oriented: to complete every repeat and set, to make five positive comments during the course of practice—or it could be technique-oriented, such as to breathe bilaterally, swim more quietly or control head movement.
And finally, getting the team to believe in the plan will be more powerful than whatever content the coaches plan.
Tapering for Masters Meets
Tapering for the Masters swimmer is a truly intriguing topic. Without getting deeply technical in considering the aging process, it occurs to me that what works for younger athletes—tapering with more rest due to maturing muscle development—may work in reverse for older athletes.
To the extent that the aging process reduces muscle mass, as you move into your late 40s and beyond, does it make sense that once again you would want to taper more briefly? The complicating factor is that we are also less resilient as we age, so it generally takes longer to recover from a given workload or intensity.