Adding strength to endurance training does not enhance aerobic capacity in cyclists

Scand J Med Sci Sports. 2015 Aug;25(4):e353-9. doi: 10.1111/sms.12338. Epub 2014 Dec 1.


The molecular signaling of mitochondrial biogenesis is enhanced when resistance exercise is added to a bout of endurance exercise. The purpose of the present study was to examine if this mode of concurrent training translates into increased mitochondrial content and improved endurance performance. Moderately trained cyclists performed 8 weeks (two sessions per week) of endurance training only (E, n = 10; 60-min cycling) or endurance training followed by strength training (ES, n = 9; 60-min cycling + leg press). Muscle biopsies were obtained before and after the training period and analyzed for enzyme activities and protein content. Only the ES group increased in leg strength (+19%, P < 0.01), sprint peak power (+5%, P < 0.05), and short-term endurance (+9%, P < 0.01). In contrast, only the E group increased in muscle citrate synthase activity (+11%, P = 0.06), lactate threshold intensity (+3%, P < 0.05), and long-term endurance performance (+4%, P < 0.05). Content of mitochondrial proteins and cycling economy was not affected by training. Contrary to our hypothesis, the results demonstrate that concurrent training does not enhance muscle aerobic capacity and endurance performance in cyclists.

Keywords: Mitochondrial biogenesis; PGC-1α; exercise; gene expression; resistance training.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anaerobic Threshold
  • Bicycling / physiology*
  • Citrate (si)-Synthase / metabolism
  • Humans
  • Lactic Acid / blood
  • Leg
  • Male
  • Mitochondria / physiology
  • Mitochondrial Proteins / metabolism
  • Muscle Strength
  • Oxygen Consumption
  • Physical Conditioning, Human / methods*
  • Physical Conditioning, Human / physiology*
  • Physical Endurance / physiology*
  • Quadriceps Muscle / metabolism*
  • Quadriceps Muscle / physiology
  • Resistance Training*


  • Mitochondrial Proteins
  • Lactic Acid
  • Citrate (si)-Synthase