Q: "My son, a lacrosse player, would like to try out for High School Cross Country this upcoming Fall. Any suggestions on how he should prepare? He currently has very little endurance so I thought it would be best for him to get started before the actual season begins."A: Great question. While my recommendations will vary depending on the individual (injury history, running history, other sports they may be playing currently, how much time they have to prepare, are they an elf, dwarf, wizard, or human, etc.), here are some general guidelines for the healthy, human, individual:

1. Start NOW

You hit the nail on the head when you mentioned it would be best for your child to start now.

Too frequently I see people wait until the last minute to begin a running program, and then, one week before the season (or a race), they have a moment of "Oh crap I haven't been running but practice starts 5 days from now, how about I go jump into a thousand mile run to prepare" and then they jet off down the neighborhood.

This concept may work when applied to a procrastinating college student who crams for exams at the last minute (not that I would know anything about that), but not so much with regards to running. Attempting to shove in last-minute, high volume, running sessions one week before the season as a sure-fire way to accrue an injury (not that I know anything about that, either...), which obviously doesn't help your son's chances of making the cross country team.

Slow and steady really does fit the bill with regards to running (and lifting) programs. Don't delay any longer in getting started, and start with a very short distance. Resist the urge to do too much, too soon.

2. Begin with "Rectangle Sprints" on Grass

This is my all-time favorite way to ease people, including myself, into running. It's easier on the joints compared to running on concrete, it's not terribly taxing, and it sets the stage quite nicely for future training.

How ToDo It

Find a soccer field (roughly 100-110yds long), and "sprint" the straights, then walk the sides. The sprints should NOT be a maximal effort run, but around 85% top speed while focusing on good technique and steady breathing. After you walk the endline, you'll then run down the other sideline. Walk the endline, and.....congratulations, you've just discovered why these are called rectangle sprints.

If, upon walking the endline and arriving at the next corner, you find that your heart rate is still jacked up through the roof, take some time to let it slow down. Ideally it will be back to 140bpm before you initiate the next sprint.

Frequency: 2-3x/week

Repetitions: 4-12. Begin by performing no more than four total rectangles, which would be eight total sprints (not kidding, that's all you need for Day 1). Increase the total rectangles by one each session, capping it out at twelve.

3. Next, Add Hill Sprints

Hill sprinting has to be my favorite form of conditioning. Super easy on the joints, challenging, and won't leave you feeling too banged up.

You can typically find a good hill near a lake, reservoir, or school. Google Maps is your buddy in this department. Try your best to find a GRASS hill, and one that is relatively steep. Don't worry if it's a super long hill; you can always start partway up it if the hill is crazy long (you don't want the sprint to last longer than twelve seconds).

I actually wrote out my guidelines for hill sprinting HERE, so click the link for the "How To."

Begin these roughly 1-2 weeks after initiating the rectangle sprints, and start with a frequency of 1x/week, never exceeding 2x/week.

Also, of note: Just because hill sprints are easy on the joints and don't tend to affect recovery as much as other "cardio" modalities, they are downright brutal, and not for the faint of heart.

4. Begin Steady State Running, Following the Rule of 20%

Finally, add steady state running. There are so many strategies one can use here, but to keep it simple, start off with a 20-30 minute run. This can be done 3-5x/week, starting on the low end and carefully monitoring recovery.

The 20% rule is a MUST when it comes to designing and implementing conditioning programs.

Never increase the total time, or distance, by more than 20% each session. So, for example, if you run for 30 minutes on Day 1, don't run for more than 36 minutes on Day 2. Or, if you perform 750 total yards of shuttle runs on Day X, don't do more than 900 total yards of shuttles on Day "X+1." (How bout that algebra, hmmm?)

This will allow you to improve quite a bit while minimizing the risk of injury.

Closing Thoughts

What about HIIT (High Intensity Interval Training)? This is a topic for an entire other post, but in the meantime, don't worry about it. HIIT certainly has its place, but, for now, stick to the three modalities listed above.
Once you move into your steady state work, feel free take a break on the days you feel particularly "beat up" and do some rectangle sprints instead. Personally, I love them for "in-between" days and often find that they invigorate me for my subsequent sessions compared to taking the day off completely.
You can still supplement your steady state running with hill sprints 1x/week to give the joints a break (in fact, I recommend this).
Take at least two days off a week from running, during which you can......see the next point.
Be sure you're involved in a quality resistance training program. Amongst the running world, this this has to be one the most underappreciated components of a quality running program.