Dose-Response Relationship Between Interval Training ...

[jliddil]

Dose-Response Relationship Between Interval Training Frequency and Magnitude of Improvement in Lactate Threshold
Int J Sports Med :
DOI: 10.1055/s-0030-1254136
Abstract

The purpose of this study was to determine if interval training at 110-120% of peak power output one and two days/wk in addition to habitual training would elicit improvements in lactate threshold (LT) in a dose response manner. Twenty physically active individuals completed this study: age - 21.1±1.3 yr, height - 172.1±7.4 cm, body mass - 68.4±9.1 kg, VO2max - 45.3±5.2 mL/kg/min; and were randomly assigned into two separate 6 wk training groups - either 1 day/wk interval training or 2 days/wk interval training at 110-120% of peak workload (from an incremental exercise test) on a cycle ergometer. After 6 wk, LT (% VO2max) increased significantly (p<0.05) in both 1 day/wk (4.3±3.2%) and 2 days/wk (8.2±2.6%) groups. A two-factor mixed ANOVA identified a significant interaction between exercise frequency and LT (%VO2max) values (p<0.05) indicating that LT responded differently to 1 day/wk and 2 days/wk of interval training. Findings from the present study show high-intensity, interval training to be a successful strategy for modifying this important metabolic threshold. Moreover, results suggest that there is a dose-response relationship between frequency of interval training and the magnitude of LT improvement.

[Tinus]

Higher dose of training will improve positive training response... is there also something new?

[jliddil]

From the article:
Although investigated previously, the attributes of a training program aimed at positively modifying LT are not well understood [19, 23] . Compared to VO2 max, for which there are well defined guidelines [2] for the frequency, intensity, and duration required to elicit meaningful changes, no such similar recommendations can currently be made for improving and maintaining LT. To date, most of the research centered on training program characteristics required for LT improvements has focused almost exclusively on the exercise intensity component. Moreover, much of the previous work on training intensity has focused on performing either steady state or intermittent training bouts at intensities corresponding to (or near) the LT [1, 4, 6, 25, 32] . Although these aforementioned strategies have proven to be an effective training regimen, less is known about the utility of high-intensity, inter-val training for improving LT [14, 15] . It has been suggested that high-intensity interval training might be an effective strategy, as this training methodology has been shown to rapidly increase expression of monocarboxylate transporter (MCT) protein and improve mechanisms of lactate clearance [9] . Further, to our knowledge there is no research focused on the dose response relationship between exercise frequency and improvements in LT. Given the strong relationship between LT and endurance performance, additional work in this area is warranted and prompted the present investigation. The purpose of this study was to determine if high-intensity, interval training at 110 – 120 % of peak power output one and two days per week would elicit improvements in LT values. We hypothesized that both high-intensity, interval training groups would be effective at raising the LT, with greater improvements (in a dose response manner) observed in the training group performing two interval sessions per week.

[Tinus]

Ok that's a big surprise. Nobody ever before showed well enough that high intensity interval training improves LT.

[Ralph Earle]

I know we're all supposed to "give 110%," but just what does "110-120% of peak power" mean? It certainly doesn't make sense in English.