Garmin's "Load"

Disclaimer: I always listen to my body first. I know Garmin stats are just numbers, helpful at times, but not the full picture. I've only had Garmin for a bit over a year, so I'm used to training without a smart watch.

That said, Garmin defines it's "training load\*"\* as the 7-day sum of EPOC (excess post-exercise oxygen consumption), adjusted for fitness level and compared to your longer-term load. I mostly use it to make sure I’m not overtraining in weeks with multi-sport cross training. I don’t often use DSW, but since it’s influenced by load and load focus, I try to keep an eye on it and occasionally use their suggestion to even out my week.

At first, I assumed Garmin's load was mostly just HR × time (area under the curve). But that's not entirely accurate, but more importantly, Garmin’s load number per activity doesn’t line up well with my RPE across several exercise types. Which makes me wonder how useful is this metric really. Curious what others have experienced.

Example: yesterday I did a 15-mile trail run with 4,000 ft vert and some scrambly terrain. 4 hrs total, avg HR mid-Z2 (44% Z2, 32% Z3, 20% Z1). Garmin gave me a load of 193. My body says it was way higher. Earlier this week, I did 12 mi/3,000 ft vert in 3 hrs, and Garmin gave me 186. Meanwhile, my “normal” trail runs close to home (5 mi/800 ft in \~50 min or 7.5 mi/1300 ft in \~90 min, staying mostly in Z2 and Z3) usually score 120-180 depending on pace. So after 2 big outings this week, the generated load just does not reflect how taxing these longer efforts feel and how much recovery I need. Garmin is suggesting a long-ish run today when I absolutely need a rest day or just lightly spin the bike!!

Another issue is that Garmin currently has my load “Optimal,” smack in the middle of my chronic load. But [Intervals.icu](http://Intervals.icu) flagged me as “High Risk” today and gave that 15-miler a 237 load vs my normal \~100 load for a 5 mile trail run, which feels much more accurate, given it’s over 2x my normal runs. TrainingPeaks also doubled my TSS for these big days. So even using Garmin's own data, TrainingPeaks and Intervals .ICU are giving me useful load data that is more in line with my RPE.

So is Garmin's Load and EPOC just not built to capture the strain of longer alpine efforts? I’ve noticed the same with big backcountry ski days where Garmin consistently underestimates how exhausted I am afterwards.

I'll keep mostly ignoring Garmin's "Load", but just curious what others have found with multi-sport or long outings with significant elevation.

(also posted in Garmin sub but thought this might be specific to trails and elevation?)