I ball girl at tennis tournaments - not so fun when Tsonga is serving at your leg - and for the week I put my Lantus down one or two at most and usually only inject my Novorapid for main meals and not snacks. This however is for a week of non-stop concentration and movement in the full sun (don't know if this affects anyone else but put me in the sun and my insulin seems to work ten times more efficiently!). Hope this is some help!
Used to use Lantus and it's a nightmare when it comes to exercise. Basically it has a very long tail to it's activity, it's meant to last for 24hrs, but the main curve which kicks in after about 4hrs tends to last for about 18hrs ish depending on dose size, and the tail can linger on for up to 2 days. Due to fluctuations it caused on one a day I ended up on the twice a day Lantus, but the tails just ended up over lapping and it got even messier to keep control of. Before a sportiv I would need to stop my Lantus two days before hand, and just go off correcting with the basal till after the ride as riding with the Lantus in my system was causing a massive increase in the need for constant carbs (which yes is still necessary while riding but not quiet as much).
When finally getting a pump and not needing Lantus and having the flexibility to knock my bolus down easily and quickly it pretty much doubled my range capable due to not needing to carry as much fuel.
I ran track throughout high school (just graduated) on both Lantus/Humalog and the omnipod. Let me tell you, the omnipod made it so much easier. I know he had a lot of problems with the Animas Ping (read a comment), but I have to support the omnipod here. I've never had a problem with it like you described.
Back in freshman and sophomore year, before I started pumping, I ate peanut butter sandwiches to boost my blood sugar before practices and sipping gatorade throughout practice to keep it in the right place. Honestly, it's a guessing game. The DNE gave me suggestions of carb loads to eat and various ideas, but none of them worked quite right, I worked out my own routine.
Sorry that this is pretty useless information. I just want to reinforce that it's trial and error, and that he's going to have to test very frequently for the first week or so. He may want to consider a CGM, although it's going to be very hard to keep it from being damaged during drills. It'll be useful during conditioning.