RESEARCH: studies reviewed this week - 18 May 2020 to 24 May 2020

TRAINING: Influence of Interval Training Frequency on Time-Trial Performance in Elite Endurance Athletes

Interval training is an effective means to improve performance. However, prescribing and distributing the frequency and duration of intervals is not extensively researched. This study looked into two protocols over a 12 week period and matched the training load for each. The two groups were:

• Low frequency: 2 interval training sessions per week. 8 x (8'/2') and 6 x (12'/3') all in Z3. 1-2 rest days in between sessions.
• High frequency: 4 interval training sessions per week. 2 sessions of 4 x (8'/2') and 2 sessions of 3 x (12'/3') all in Z3. Two sessions on consecutive days, a rest day, another two consecutive sessions.

The findings of the study were that:

Two longer high-intensity interval sessions per week (LF group) for a period of 12 weeks, showed a statistically significant improvement in 8 km rollerski time-trial performance.

An interval training model with lower training frequency but longer duration per session appears to be more effective.

PRACTICAL TAKE AWAY - lower frequency interval training is more effective

• Interval sessions in zone 3 appear to elicit the best effect when the total effective duration is≥60 min.
• Two interval sessions per week is an ideal training prescription.
• Accumulating more time at intensity, rather than increasing intensity or increasing frequency, appears to be optimal for training development.

TRAINING: Aerobic high-intensity intervals improve VO2max more than moderate training

This is study "compared the effects of aerobic endurance training at different intensities and with different methods matched for total work and frequency". I think that the outcomes of this study are already quite well known and accepted, however, it's useful to have a reminder of the optimal interval duration for achieving a training goal:

High-intensity aerobic interval training resulted in significantly increased VO2max compared with long slow distance and lactate-threshold training intensities (P<0.01). The percentage increases for the 4 x 4 min group [was] 7.2%

PRACTICAL TAKE AWAY - VO2 Max sessions should focus on ~4' intervals

• VO2 Max intervals sessions should focus on intervals of 3-5' duration.
• Recovery periods should be based on an approximate 1:1 ratio (3' recovery in total is probably enough).
• Total time at intensity should be 12-20'.

TRAINING: The Effect of Age on the VO2max Response to High-Intensity Interval Training

As athletes age certain aspects of their physiology no longer respond or adapt to training stimuli that were effective in the past. While it is important to be cognizant of all the stresses high intensity training can bring (especially the impact of running), it is also useful to know that certain training protocols are still effective regardless of age. This study showed that:

In healthy individuals with an aerobic capacity typical for what is observed in the population, the training response is likely not affected by age in a short-term training intervention but may rather be affected by the initial training status. These findings imply that individuals across age all have a great potential for cardiovascular improvements, and that HIIT may be used as an excellent strategy for healthy aging.

PRACTICAL TAKE AWAY - athletes of all ages can benefit from HIT to develop VO2 Max.