High-intensity interval training during the season – good or bad?

p1010901This is the question on many people’s mind. How should I train when the swimrun season kicks in?

Many are under the impression that the best way to stay fit and ‘race ready’, is to leave out the high-intensity training (HIT) sessions and do the bulk training at a slower pace. But is it the best way to stay at the current level and peak out, just before a race? HIT is more or less left for the pre-season type of training since it poses a greater risk of  injury, and many believe that you can’t get any faster anyway. Now research is helping us understand this differently. Throwing in a HIT-session in the middle of the season can actually be a good thing.

Check out this study from a team from Taiwan and USA, and don’t forget that recovery, as we have written about before, is an essential part of your training regime.

/The WoS Team

LEE Chia-Lun et al (2016). Effectiveness of 2 weeks of high-intensity interval training on performance and hormone status in adolescent triathletes, The Journal of Sports Medicine and Physical Fitness

Weekly training volumes for triathlete are typically higher and may cause fatigue and musculoskeletal injury risk. High-intensity interval training (HIT) is a potent time-efficient strategy to induce adaptations normally associated with traditional endurance training. Therefore, the aim of this study was to investigate the effect of 2 weeks of in-season HIT on exercise capacity and hormonal responses in young triathletes. Twelve adolescent triathletes performed 18 sessions of HIT over 2 weeks including swim, cycle, and run events. The 6-day training blocks were separated by 1 day of recovery. Pre- and post-training, peak oxygen uptake (V ‧ O2peak) and exercise performance were assessed, and blood samples were obtained to detect changes in hormone and metabolite levels.
VO2peak was significantly higher (p =0.02) post-training (56.4 ± 8.1 ml·min-1·kg-1) versus pre-training (55.1 ± 7.5 ml·min-1·kg-1). Mean power and total work during 6 × 10 s repeated-sprint tests significantly increased (p = 0.03) after HIT. Additionally, 750 m swim time (pre- vs. post: 689.7 ± 102.5 s vs. 662.0 ± 75 s, p = 0.01) and 20 km cycling time (pre- vs. post: 1,856.6 ± 274.8 s vs. 1,705.4 ± 266.8 s, p = 0.02) were significantly lower post-training compared to pre-training, but there was no significant difference in 5 km run time after HIT (pre- vs. post: 1,315.8 ± 81.3 s vs. 1,292.0 ± 112.9 s, p = 0.31). In contrast to pre-training, ammonia concentration was significantly increased (p < 0.01) and creatine kinase concentration was significantly decreased (p = 0.02) post-training.
These findings suggest that two weeks of HIT using HR-peak as a monitor of physiological intensity improved VO2peak, sprint performance, and triathlon-specific performance in adolescent triathletes and attenuated levels of muscle damage.