I'm a freshman in college, ran xc/track for 3yrs in HS (17:11/10:13/4:47), but have always had an injury that pops up every couple months/whenever I increase volume beyond around 40-50mpw (posterior tibial tendonitis, gotten it eight or nine times I think?). I've been trying out a new method of only running 3 core sessions per week with xt'ing filling in the gaps, and I've had no issues when doing that. My thinking is that the workouts/long runs build specific fitness, and the xt'ing works on aerobic fitness without risking injury. However, I was wondering if this is really a sustainable way to train/improve in the 5k. Any thoughts?
Sample week looks like this:
M: 45min swim + 15min aquajog + grass strides
T: AM: Sprint WU, 6x50m sprint, 1.5mi CD PM: 45min stationary bike
W: 45min swim + 15min aquajog + grass strides
R: 1mi WU, 25min tempo (~6:00), 1mi CD + strides
F: 45min swim + 15min aquajog + grass strides
Sat: plyos + 1hr stationary bike + grass strides
Sun: 10mi LR (steady effort, ~6:50-7:00)