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Annual DEXA Scan - Results and Observations

I am posting this to show body comp changes from before Triathlon to after a year of IM training.

3 years ago (2016) I went to the Fitness Institute at the University of Texas and got a DEXA scan to get a baseline of my body composition. Three years ago, I was not doing Triathlons, but I was in decent shape. I was doing some running, some spin classes and weights.  The next year (2017), I went back to get another DEXA scan. At this time, I had been with EN for a couple months but I was in much better shape this year. I was much stronger compared to 2016 and had more endurance.  My first IM wasn't until April, 2017 so this scan was before the longer training days. This year (2018), I went back to get another DEXA scan.  At this point, I had done 2 IMs, my endurance was MUCH better compared to previous years, but I was weaker as I wasn't lifting weights as much. I think its very interesting how the body adapts and changes based on the training.

While my results from the first year to second year where not surprising to me, the results from the second year to the third year did surprise me. I figured that since I lost 12 lbs since last year that my body fat would have also dropped.  Instead, my body fat stayed at the same 9.7%.  This doesn't upset me, it just surprised me. I am actually happy it didn't drop, as I now have a better understanding of how much weight I can lose for a race and/or how my body fat will change with addition of lean muscle.  Before the results of this last DEXA scan, I would have figured that I couldn't have lost some weight and still be at healthy fat levels. I haven't swam since August, so I'm thinking that is why I lost some arm mass :) 

Besides getting the benefit of seeing a breakdown of where you have muscle and fat, you also get a bone scan that shows if you are losing bone. I'm a little low, but have been holding steady (but its still something to watch). The scan I got also shows the amount of Visceral Adipose Tissue you have.

If you have the ability to get a scan done, I would recommend it. I pay about $80 to get a scan, and am going to try to go every year as a sort of check in. 

I also plan on using this as an indicator of how much weight I can safely lose before a race. I'm not knowledgeable in this area, but I would think that a DEXA scan would be a great way for a person to see where they can improve their body comp.  At any rate, here are my results so you can see what information a DEXA scan can provide you.  The baseline is the first years measurements.

Any comments on other ways I could use these results would be great.  Thanks!

 


Comments

  • Very interesting, I have wanted to do this but no place here in Abilene. I may have to run down to Austin and check this out.
  • @Tim Sullivan  Interesting how your Visceral Fat went back to baseline. From 2016 to 2018 you gained it and then lost it. VAT is an important marker to watch. Body type has a lot to do with it as well. Some people gain weight very easily in the trunk.

    It's hard to gain or maintain muscle with mega hours of endurance training. Weight lifting promotes production of testosterone, which most endurance athletes don't do much. Sleep also promotes growth hormones and reduces cortisol ... all zappers of muscle. Late night Zwifting could hurt your gains :)

    Your lean mass is 127 pounds. That is the minimum grams of protein you should be eating each day. 
    i.e. 127 gm protein/day

    Lastly - ignore that calorie in calorie out chart.

    I plan to do this. University of California Davis - Sports Medicine does it. 

    Good stuff.
  • Thanks @Sheila Leard. Yeah, the UT person said to ignore the calorie in out chart as well.  She said that was just for people not doing much. She also said the Lean Mass Index wasn't as applicable to endurance (low fat) athletes but was surprised that I was still at a decent percentile in it. I think my protein intake is good, but I'll track to make sure. I think I do a good job sleeping, but I do have a late night Zwift race I've been doing :).

    The DEXA scans are definitely worth doing in my opinion.  The entire process was only an hour (if that). 
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