@sryke rather than frame the discussion as “bringing AeT and AT closer together” I’d simply propose saying that one outcome of a well developed “Base” is that fat as fuel is increased at higher power outputs.
Graphically it looks like this: Fat burning 2 | Alan Couzens or this Solid base vs unstructured training - case study with results or this chart:
on page 6 of the 2006 book Base Building for Cyclists by Thomas Chapple. Hard to read my bad pic, the caption states:
Graphs showing how, after following the base training program outlined in this book, the athlete improved fat burning, raised the upper training threshold (or fitness ceiling), and increased the power output relative to heart rate. The athlete did so by training at lower intensities than in previous base training. Although the athlete slowed down, he became faster.
And the before/after tables:
Calorie Utilization of Fat (KCal/min)
Zone1 | Zone2 | Zone3 | Zone4 | Zone5 | |
---|---|---|---|---|---|
Before | 4.2 | 3.4 | 2.4 | 2.0 | 0.0 |
After | 6.7 | 6.3 | 4.9 | 4.5 | 1.0 |
The lower aerobic threshold only went from 163 to 168W. Power at ~162bpm went from 209 to 214W. Not sure how to read the anaerobic threshold, but zone5 is wider and it looks like a higher top-end.
Pretty clear that fat as fuel has increased. Now if you do 45-60 minute races you may not care as much, but if you do longer races or longer adventure / epic rides then it makes a real difference.