A lady member (age 50) of our running group suffers from an underactive thyroid being treated with medication. She has been running with us starting as a total beginner for 2 years and is finding that now as her fitness and general well being has improved and her pace increased once she hits 7/8 miles all energy goes.
Does this mean that her medication requires adjusting?
Her own theory is that because her metabolism is slow then after a certain amount of exercise her body can no longer provide her with the energy that she needs to sustain a better pace over a longer distance. We are currently training for the Glasgow 1/2 Marathon in September.
This lady has done so well and this weekend after our training session she was so upset because having completed about 7 miles of a 9 mile run in pretty warm conditions she was totally exhausted. She does take fluids on her runs so felt that she was hydrated enough. After the session she recovered quickly having had something to eat and a lucozade (non sport) drink.
Any help or you own experiences would be appreciated.