While there are many variations and combinations possible, in order to keep things simple for parents and so the kids can see their progress, I try to keep it as simple as possible. A few basics to undertand:
1 - The body is stimulated to adapt in different ways depending on the intensity, duration (time/distance), and recovery time between hard repetitions.
2 - There are always 3 different energy pathways/systems (the chemistry and body functions that produce the energy to power our muscles) in play. Which "system" is doing most of the work at a given time depends on the things stated above (intensity, duration, recovery time). They are:
Aerobic Energy here is derived from the oxygen we breath in reacting with the carbs and fat in our body to produce C02. This is where most of our energy comes from at while running at lower intensities. This system is fully developed by age 12. When we reach an intensity at which the aerobic system can no longer keep up with oxygen demands, the body begins to produce energy anaerobically. This point is called Lactate Turnpoint (Formerly referred to as Anaerobic Threshold still commonly used). There are 2 different anaerobic energy pathways which follow.
ATP-PC Think of this as a powerful, but limited battery charge for short, high intensity efforts. Once depleted, this system takes 5+ minutes to fully "recharge."
Glycolysis As energy supplied by ATP-PC begins to run low the body begins this process which produces lactate in the blood. After about 40 seconds lactic acid begins to accumulate. Recent studies show that this energy system is not fully functional until we reach about 18 years of age. What this means is that lactic acid accumulates faster in adolescence and younger and takes longer to clear/metabolize. This is an important consideration when planning workouts and race strategies.
No worries when training the aerobic system, but take into account the pros and cons of LSD (long slow distance).
When using the ATP-PC system, use short fast repetitions (less than 20 seconds/100 meters) with full recoveries that focus on good mechanics, the nervous system, muscle recruitment, leg turnover, etc.
Go easy when training the glycolytic system, only go 10-20 second into lactic acid accumulation or 250-350 meters. Allow at least 5 minutes (at least some of that easy jogging) between reps to allow lactic acid to clear and ATP-PC to recharge.
A primary focus for any runner but especially for adolescence and younger is to raise lactate turnpoint/threshold to allow the runner to maintain a higher intensity before crossing the line into glycolysis. These workouts include cruise intervals, tempo runs, and fartleks. They a focused intensity just below/above lactate turnpoint.
Keep what I'm going call interval workouts to a minimum. These are workouts that are faster than race pace with short incomplete recoveries. These are very appropriate and effective for runners over the age of 18, but I believe are hard on and ineffective for younger runners. Unfortunately these kind of workouts account for the majority of what you'll see in HS and MS programs. The reason? Most coaches don't read enough and stay current? That's how they were coached back in the day. They're getting workouts out of Runners World or similar sources that are really geared toward adult marathon runners? They may be more interested in short term results over long term development? They be experienced and well read, but interpret and put together the information out there in a different way. My views are ever changing and I'm always looking to share ideas and learn from these people.
I believe that to really get the benefit of a workout, it needs to be repeated 4+ times, but this can limit the variety of workouts/stimulus that we can fit into a training plan. This is something to wrestle with when planning. What's more important variety of focus on the things you believe will help most. There's just never time to do it all. Be over ambitious and you'll end up over training. You should also consider recovery time and periodization (see posts on those subjects).
Recovery Runs and Long Runs
We should be able carry on a conversation while running. We can measure these by time or distance. Recovery runs on days between "quality" workouts help the body recover quicker by increasing blood flow, helping clear out "waste" from the previous day's hard workout, and replenishing muscles with glycogen. While Long Runs may not seem easy, they should be run at an easy pace. Long runs stress the aerobic system, drain glycogen stores and teach the body to burn fat while exercising, fatigue the brains favorite muscle fibers and forces it to recruit and strengthen less used fibers, and usually account for about 25% of weekly mileage. As long slow runs teach the body bad biomechanics and teach us to run slow, we should undo the "damage" by finishing all these run with a few form drills and 5-6 strides.
This is my workout of choice for targeting turnpoint/threshold and to stimulate desired adaptations in type I muscle fibers (They reach top recruitment and contraction speed at around 80% VO2 Max). The short breaks allow them to run at a slightly faster pace than tempo runs and gives the kids a mental break. They're also very easy to monitor, and the guess work is taken out. I get these from "Jack Daniel's Running Formula". Assign athlete a VDOT from the table on page 48-49. Then use the corresponding "T pace from page 52. Use short 1 minute jogging recoveries to keep the HR elevated. Ideally each rep is about 5 minutes. I will sometimes shorten them if the kids are tired and struggling to keep the pace. My goal is usually to get 15 - 25+ minutes at the desired pace.
300's (250-350 meters or 50-60 second reps)
Here we're working on speed endurance and glycolysis. Because as stated earlier, lactic acid is hard on the young athlete and starts to build after about 40 seconds, we only go 10-20 seconds past the 40 second mark. Recoveries should be 5+ minutes with some easy running in order to clear lactate and recharge ATP-PC. We usually don't run more than 6 reps.
100's (15-20 seconds)
We run these close to all out in order to stress the nervous system, increase muscle recruitment, power, and turn over, and improve biomechanics. I like to have them jog an easy 300 back to the start line and wait a total of 5 minutes between reps in order for ATP-PC to recharge. We normally run as many as 6-10 reps.
Having strong core muscles is of the utmost importance. Strong core muscles control the hip bone giving the athlete more power when they run and preventing injury. Many injuries can be linked back to week core muscles. When we talk about the core muscles, we're not just talking about strong abs from doing crunches, we want all the muscles (upper, lower, front, side, and back) to be strong. As we don't usually have time for core workouts during practice, this responsibility falls on the athlete. A good core workout should be done at the least once a week, but preferably 2-3 times a week. The off season and preseason is a good time to really focus on the core, so that during the competition phase, we only need maintain vs. build strength. It's a good idea search "core workouts/exercises for runners". There are also a lot of good exercise videos that take you through a well rounded core workout. I personally have a hard time giving my core the attention it needs unless I'm following a video or having someone else push me through a workout that's long enough, and hard enough to really build those muscles.
Tempo Runs and Fartleks
These, along with cruise intervals, target lactate turnpoint. The pace should be pretty close to that of the cruise intervals but without breaks. I would describe it as comfortably hard or just below race pace. If using a hear rate monitor, run at about 85-90% MHR. Once this pace is established, you can throw in slightly above turnpoint surges (fartleks) , maybe hitting 91-92% MHR. The athlete should be able to settle back into tempo pace after the surge. If they have to slow down much more than that, then the surge was to hard. There was too much lactic acid accumulation, and they did not get the desired stimulus.
Hill reps may replace and/or supplement speed workouts from early to mid season. Running uphill teaches the brain to recruit more muscle fibers and builds power. Consider what speed intervals they might be replacing when planning the distance/time of each rep. Will lactic acid begin to accumulate sooner than 40 seconds because of the increased muscle fibers being recruited? I don't yet know the answer to this question, but it sometimes feels like it.
200's (35-40 seconds)
I like to use 200's in early season conditioning, recovery weeks and pre-meet speed workouts with short recover time before the meet as they're not long enough to stress the glycolytic system and not fast enough to really stress the nervous system.
150's (30 seconds) @ race pace
These are what we run at the very end of the season during the tapering phase of sometimes the day before a race if the athlete is well rested from previous workouts and just wants to stay fresh. Walk/Jog the 250 between reps.
40's and 3/3/3 drill (7 seconds)
This is about the only time I ask athletes to give everything they can in practice. The goal is to stress the nervous system and train top end speed. I think its good to run them from a standing start and from a flying start. Run them in sets of 3 with 5 minute recoveries and a 10 easy recovery run between sets. I use the 3/3/3 drill when we can't get to a track. For this drill slowly speed up, then run all out for about 3 seconds, coast for 3, then finish with another all out 3 seconds. These could be timed, or one could set up 4 cones/markers about 20-25 meters apart and follow the same procedure. Run in sets the same as 40's
I think one of the best things we can do with young runners is teach them to pace themselves properly during a race. Kids who race that only do their events in races usually end up picking up the bad habits of the other kids. I hope to avoid this by having them time trial with experienced runners before they start getting in actual races. Time trial also help give us a measurement of where the athlete is and give them an opportunity for a PR when traveling to a meet isn't an option.
After discouraging these kind of workouts, a recent conversation with coach Skrbac convinced me to add this one. His argument was to instill muscle memory at goal race pace. I feel we're usually addressing this in actual races and time trials but if the race schedule is light and time permits, I can see the benefit of working a few of these into a training plan. The rule of thumb use to be that the cumulative distance if the intervals should be 1 and half times the distance of the race you're pacing. But now, especially for longer races, I wouldn't go much over the distance of the race. Another rule of thumb is to keep the distance of the intervals to one third the race distance or less. Recoveries between reps should jogged. I still lean towards longer recoveries, but not necessarily a full 5 minutes. Maybe more like 3 minutes.
5k Pace Intervals
Reps at this pace rev your aerobic system to almost 100%. It's counter productive to run reps at this effort level that are longer than 5-6 minutes. Shoot for 1200-1 mile reps. These will recruit slow-twitch, intermediate, and fast-twitch fibers and increase capillary and mitochondrial density for all. They also build stroke volume for each pump of the heart as well as improve running economy for races 3k-half marathon. 3-4 reps per workout with (R 1/2 to equal to duration of rep).
WHAT: 3 x (4 x 400m) at approximately 3 seconds faster per lap than 5K pace (somewhere between 1500m and 3,000m pace), with 30 seconds between each 400 and a lap jog between sets.
WHY: Short rests between hard, fast intervals help teach the nervous system to adjust to faster running, promote stride power and efficiency, and allow you to practice maintaining form and speed when fatigued. Willis explains, "You use short rest in between hard, short intervals to generate some lactic acid in your legs, then practice running with heavy legs to increase your lactate threshold. This helps for the finish of a 5K when you are sprinting after having run almost 3 miles."
WHEN: Do this workout in the month preceding an important racing block, when you're looking to peak in a series of races.