Heat Training for Haemoglobin Gains

Editor’s note: Amateur athletes have discovered that heat training is not just for preparing for a race in a hot climate – but also to boost haemoglobin for performance gains. Amateur trail runner Nikolai Antonsen Segtnan (Instagram @segtnan) did exactly that in his preparation to beat a course record long considered ‘unbeatable’.

He kindly shared details of his heat training, along with before and after data. We offer huge congratulations to this ambitious self-coached athlete.

Background and mission

I am a 30-year-old medical doctor with soccer background, from Norway. I have for the last year done around 15 hours/week of running to beat the course record over “Syv Søstre” (“The Seven Sisters” in English).

It’s a chain of 7 peaks, with a total of approximately 3000 meters of elevation across 22km. It’s one of the most famous mountain formations in Norway. The record was held by the cross-country skier Rolf Einar Jensen with a time of 3:43:39, set in 2015. Before that the record was held for 40 years with the time of 4 hours.

On the 23rd of September I was extremely happy to break the 8-year-old record with the time of 3:41:06. This was after trying to optimize every bit of training and restitution possible (together with working full time as a doctor). This involved a total of 9 weeks of heat training, 6–7 sessions a week, 50 min to 2 hours per session, with the last two weeks being maintenance weeks (3–4 sessions).

Results of heat training:

Haemoglobin levels

13,7 — 1 week before start of Heat Training

13,4 — 5 weeks of Heat Training

15,0 — 7 weeks (could have been a little dehydrated when taken)

14,3 — 8 weeks of heat training


First 4 weeks were gradually more stressful for the body (also had three days of flu), before it started easing up on the 5th week. From there I got a significantly better feeling than ever before, from week 6/7 until  week 9 where I competed and ended the heat training.

Other results

  • 10km race: 34:13 after 9 weeks of heat, from 34:56 in June pre heat training. Pretty much the same conditions.
  • Data 30 min into 10 km race
    • after 1 week of heat training:
      • Pulse 174
      • Bodytemp 39.03
      • HSI 5,43
  • after 9 weeks of heat training:
    • Pulse 175
    • Bodytemp 38,72
    • HIS 0.26

Temperature, weather and clothes (except addition of running backpack at the skyrace) was the same.

  • Lowest pulse during night: 34/35 bpm last weeks of heat training, from around 42/40 pre heat training.
  • Pulse during easy runs went from approximately 125 to 115. This was the same during threshold sessions in the last weeks – it was hard getting my pulse into the upper zone three, while at the same time having an excellent feeling in the legs.
  • HRV raised and it was much easier to maintain a low stress levels on my Garmin watch during the day.