I cant get past 4.15

[samdive]

Sorry if I'm a bit late responding - but I'd say the answer to this thread lies in its title

tell yourself, "I can't get past 4 15" and you never will. Tell yourself "I'm going to do 4 25" today and you might just do it....

try a bit of positive thinking and maybe that'll avoid having to do "wind sprints" (whatever they are)

PS this is second hand advice from Benny B that worked for me!

 

[hteas]

Wind sprints are short bursts of absolute maximum effort, followed by a short relaxation period. In the pool I do 25 yd/m (30 seconds) all out using a kickboard, followed by 1 minute relaxation, the do another 25 yd/m, again followed by a short break. I do 10 to 15 of these. If it's too easy, then drop down to 30 second rest breaks.
You can do it in the pool or running, running stairs or hills, or whatever. The idea is to get your heart rate to it's maximum and keep it there for a little while (around 30 seconds) several times in short succession, followed by brief rests stops to help your heartrate drop back down and clear out some of the lactic acid.
You get a real workout for your lungs along with training to get your legs used to the lactic acid burn, and you are cycling your body from normal to hypoxic/hypercapnic and back severa times, like your body's response to several dives in a row.

Works for me,
Howard