I started looking into the idea of iTRIMP in early 2009 by conducting some basic studies. However a group of Italian researchers mainly led by Vincenzo Manzi were the first to publish a full training study in 2009. They have conducted the majority of research with this method which I believe shows greater validity than other methods of internal training load and deserve great credit for advancing the work in this area from which we all now benefit.

Using this method the TRIMP weighting is based on the individual’s own heart rate–blood lactate response to incremental exercise, as measured during a standard lactate threshold test protocol. Furthermore, as a development on previous methods Manzi, et al., (2009) did not use HR zones or mean heart rate. The TRIMP scores were calculated for each HR reading and summated to give an overall TRIMP. In comparison to methods employing zones this meant they had effectively created a zone for each HR reading from HRrest to HRmax. Therefore, these authors individualised the weighting to the athlete, which goes beyond the individualisation by gender (Banister, 1991) or group (Stagno et al., 2007). Moreover, the iTRIMP weighting is not arbitrary as in the case of Edwards (1993) and Lucia et al (2003). Consequently, this method overcomes many of the limitations of previous methods.

In 2009 I presented the results of a small-scale study at the International Sports Science and Medicine Conference in Newcastle. The study compared the TRIMP score of an incremental bout of exercise calculated by three different methods. Banisters method and a group specific method (gTRIMP, similar to Stagno) were compared to the iTRIMP method. The results showed that the gTRIMP and iTRIMP scores were significantly different to the Banister methods. Although there was no significant difference between iTRIMP and the group specific method there was large variations for some individuals (upto ~19%). So what we could conclude was that differences and variations existed. What was required was a training study to assess the dose-response relationship.

This was delivered courtesy of Manzi et al (2009) who introduced the individualized training impulse. The results reported earlier showed that after an 8 week period of training in recreational runners, the mean weekly iTRIMP significantly correlated with changes in velocity at lactate threshold (vLT; r=0.87) and velocity at the onset of blood lactate accumulation (vOBLA; r=0.72). The mean weekly iTRIMP also showed significant correlations with changes in 5000m (r=- 0.77) and 10000m (r=-0.82) running performance. However, Manzi reported that Banister’s TRIMP didn’t show significant relationships with any fitness parameters or performance measures. The participants used in their study were recreational runners and therefore the effectiveness of the iTRIMP method needed to be also measured in team sports where the activity is highly intermittent. As the HR–VO2 relationship appears to be valid even during intermittent exercise (Esposito et al., 2004). Therefore iTRIMP method has potential for use within a soccer environment.

The iTRIMP method at this point was shown to be the only method that based it's weightings on the individual response and which is based on a physiological parameter, a combination which is evidently absent is the previous methods discussed. Furthermore the dose-response relationship presented could start to help answer the questions often asked by coaches. This groundbreaking piece of research was followed by three more published studies and one conference presentation which I believe shows the superiority of iTRIMP over the other methods used to monitor internal training load.

Recently both Manzi (Vincenzo et al., 2012) and myself (Akubat et al., 2012) had studies published looking at the iTRIMP in senior  and youth players, respectively. Manzi’s study in pre-season with an Italian Serie A team showed iTRIMPs dose-response relationships with changes in VO2max (r=0.77), velocity at ventilatory threshold (r=0.78), vOBLA (r=0.64) and Yo-Yo IR1 performance (r=0.69). My study was conducted in-season with a youth team from a championship club in 2009 (presented at the 2nd World Science and Soccer Conference, Port Elizabeth, 2010) showed a dose-response relationship with changes in vLT (r=0.67) but not with vOBLA. I also compared the weekly iTRIMP scores to session RPE and Banisters TRIMP and a modified version of Stagno’s TRIMP (group weightings but no zones). The results were similar to previous studies comparing methods to each other. Session RPE related to Banisters TRIMP, however iTRIMP did not relate to any of the methods. This showed that the method that does show dose-response relationships does not relate to those methods employed previously.

This is all great new information, but the versatility is shown best in the study by the same Italian group of researchers this time headed by Iellamo (2012). They employed the iTRIMP method to measure training load with cardiac patients. They compared the effects of a continuous aerobic training and interval aerobic training on numerous health and fitness measures. They matched the dose of exercise for each group using the iTRIMP method. There was no significant difference between the groups in all the measured variables. The measurements did shows changes over the training period, for example VO2peak improved by 22%. But there was no difference between the groups. This has major implications for practices that could be employed in different sporting situations.

Finally the results of a study I presented at the 3rd World Science and Soccer Conference in Ghent, Belgium (2012) showed how an integrated measure of internal and external training load (iTRIMP and distance covered) in intermittent exercise shows significant relationships with measures of aerobic fitness (vLT, r=0.69; vOBLA, r=0.65). The development of iTRIMP could now potentially lead to a scenario where the measurement of heart rate and distance (through GPS) in team sports at least could lead to assessment of fitness on a more regular basis. This is a finding that is showing promise and an area that I am now researching.

In summary the iTRIMP research since 2009 in my opinion has progressed the work in training load monitoring forward considerably. However practical difficulties may be a consideration you may need to take into account especially in team environments (testing, cost and analysis). Some teams I work with already have a program of regular lactate testing. At recent workshop which was attended by practitioners from the English Premier League, Championship and Super League, coaches were asked if the value they saw in iTRIMP outweighed the additional time commitments required for testing, the majority believed it did. Currently manual determination of iTRIMP and lab based treadmill testing can be time consuming. We hope to provide solutions through software and field tests in the very near future.

If you have any questions about iTRIMP or opinions why not air them on the iTRIMP forum.

If you have any questions about the implementation of iTRIMP and wish to contact me directly you can email me on



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