Solo or group sessions for the best training outcomes?

As technology and training methodology advance, we learn more and more about what is happening during training, and we become more skilled at managing it. Over the years, a key concept in training monitoring has emerged, which is the distinction between internal load and external load. The internal load reflects the stress the body is experiencing during activity. Examples of measures of internal load are heart rate and lactate values which reflect the physiological cost of movement. External load reflects what the athlete actually does. Speed and distance are both measures of external load.

While there is a clear relationship between external load and internal load in that they will generally move in the same direction, and over time, it’s become clear that these two measurements do not always sync up. As an example, the speed a runner will be able to sustain in the heat will be much slower than in cooler weather, even if the heart rate is the same. Gradually, an appreciation of the nuance of these relationships has grown.

The group effect

Training is sometimes performed both in a group setting and sometimes in an individual setting for various reasons. At first glance, it would appear that these two topics (training loads and training setting) are unrelated. However, most athletes will tell you that they prefer training in groups, particularly during challenging training sessions. Why is that the case? Could it be that they intuitively understand that they’re able to perform at the same level with less effort when training in a group? If that’s true, it’s certainly worth knowing if internal and external loads are different based upon whether athletes are performing individually or collectively, not least because failing to appreciate the differences could lead to load management errors.

While internal measures of load have often focused on physiological measures such as heart rates and lactate values (as mentioned earlier), sports scientists now believe that ‘psychophysiological’ measurements are relevant as well. How hard athletes feel they are working, as well as the emotional impact of training sessions is important. While these measurements may not reflect physiological loading, they DO reflect an impact on overall stress levels that is real and significant. There are a lot of interesting ideas here, so let’s tie everything together with a study that looks the physiological and psychophysiological impact of training both individually and collectively.

The research

A team of international researchers  recruited 16 elite Spanish middle distance runners, who were all competing at national and international level⁽¹⁾. On two separate occasions, the runners performed the same high-intensity training session, which consisted of 4 x repetitions of 500-meters with a 3-minute passive recovery between repetitions. On one occasion, the athletes performed the repetitions individually. On a separate occasion, the athletes performed the same exact session except it was performed in a group setting.

As runners often perform training both individuals and as part of a group, the purpose of the study was to compare the impact of performing that high intensity training session individually and collectively to see if there were any differences in performance, physiological response, or psychological response. To determine whether any differences existed, several tests were performed through the training session.

Since the objective of these sessions was to run fast, performance times were recorded for every repetition in order to acquire a critical measure of external load. This allowed the researchers to determine if training within a group influenced how fast the runners were able to run. As these were high intensity runs, lactate values were measured to gauge the degree of metabolic activation.

While training is typically focused on performance measures and physiological measures, psychological measures are also critical as well and provide valuable information about the session that is independent of performance physiology. Therefore, the researchers also measured the rating of perceive exertion, or RPE, which indicates how hard the athletes felt they are working.

The researchers also measured something called the ‘core affect-valence’. This is an assessment of their general emotional state. Positive numbers imply an overall positive effect or emotional state, whereas negative values indicate a negative emotional state. This measurement provided insight into the emotional impact of the two training sessions. With these various measures, the researchers were able to gain a comprehensive picture of training collectively versus individually.