Ingestible thermometer

KarenTKarenT Charter Member
edited April 2014 in General Discussion
Has anyone had any experience of using ingestible thermometers? If you have, I'd really appreciate the chance to pick your brains a bit over email for a paper I'm writing on sporting biosensors. Also, does anyone know who manufactures them?
Many thanks


  • richard_broerrichard_broer The NetherlandsMember
  • KarenTKarenT Charter Member
    Thanks @richard_broer - that's really helpful.
  • loneswimmerloneswimmer IrelandCharter Member
    edited April 2014
    Three years ago (2011) I was asked at a late date to remote advise an EC solo attempt (because of my blog).

    No-one on the team inc. Aspirant had a swimming background, but the crew chief worked in biomed devices (though in a different area). During the 6 hour qual swim they had put a ingestible thermo into the Aspirant. I only heard about this afterwards, and while I had first contact from them about a month previous to this, (in July, with swim window in late Sept!), this was the first mention I'd heard that the Aspirant was using T.I.

    The EC solo was not successful, (I was in Dover the week of the swim and Lisa C. & I both advised against swimming that day. The actual window wasn't due to open until 'the day after the swim. The weather was rubbish and the Aspirant had no rough water experience). But they went ahead and the swim was abandoned after 90 minutes. I only say this because none of those concerned continued in open water swimming so there's no followup. Here's some of the subsequent 6 hour qual report with the three charts I have: names redacted.

    XXX successfully completed his 6-hour qual swim in [US lake]. I’ve posted pictures on my facebook page, if you care to see them.

    Not on facebook, however, are some stats on which I’d appreciate your opinion. XXX has been a student of Terry Laughlin and the “Total Immersion Method”. This has reduced his stroke count down to about 55 s/min and improved his efficiency. Once in cold water, however, this stroke rate proved insufficient to maintain core temperature. See the attached graphs.

    By the 1:30 mark, XXX’s core temp had dropped below 95⁰F, and he had to return to his less-efficient higher stroke count to get his core temp back up (which he did successfully).

    It is interesting to note that XXX’s speed improved from 1:30 to 3:00 with the higher stroke count. By hour 3, however, XXX could not sustain the high stroke count, dropping to the low 60’s. This rate was sufficient to keep his core temp in the normal range (though slightly low), but his speed suffered substantially.

    Finally, his core temp dropped (expectedly) 0.4⁰F post-swim following dilation of his surface circulatory system, followed by gradual warming. A healthy response.

    My biggest question: as this was XXX’s first extended cold water swim, is it possible to assume that 4 weeks of cold water conditioning (now taking place) may allow him to maintain core temp in the Channel using his more efficient Total Immersion Method stroke? Note that the Channel temp is likely to average 3⁰F warmer. If this is not the case, XXX’s speed may not support completion within the two-tide-change time window.

    Secondly, if you are going to be in Dover after XXX , would you be willing to join XXX and myself for dinner pre-swim to share stories and talk some strategy? We’d love your comments, even if they are nothing more than hysterical laughter!


    (I love the honesty of that last line, though I never laugh at the EC).

    Here are the three charts mentioned: core-temp2-3.png. ec-qual-pace-v-stroke-2.png ec-qual-core-temp-v-stroke-1.png[img][/img]

    Though we had other discussions, what I don't have is any further objective observations from crew or subjective from Aspirant or report beyond the above email.

    After this email I advised that I personally disliked T.I. for open water precisely for the lack of thermogenesis (I'd just recently written a blog post on this very subject), and I also thought that for an inexperienced crew and Aspirant using an ingestible thermometer would be a mistake in the EC (as was their plan), giving a crew hard numbers but without the prism of experience through which to evaluate those numbers.

    Subsequent discussion was me trying the influence the training plan without imparting my personal sense of it being far too late.

    Unfortunately it did prove too close to the swim to successfully intercede in the swimmer's preparation. On top of this they attempted on a bad day.

    (The Aspirant actually got seasick swimming from the boat into Shakey for the start. The Aspirant was an very successful and reasonably well-known endurance and adventure athlete, who made the mistake of thinking marathon swimming cannot be as tough as a coast to coast races or solo Alpine-style ascents, both of which featured along with others in the Aspirant's previous achievements).

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