South African elephants (Photo: Inigo Mujika)
Boullosa DA, Abreu L, Varela-Sanz A, Mujika I.
Every 4 years, approximately 10,000 athletes participate in the Olympic Games. These athletes have dedicated several years of physical training to achieve the best possible performance on a given day. Their preparation has been supported by expert coaches and an army of sport scientists, whose overall responsibility is to ensure that the athletes are in peak condition for their event. Although every athlete prepares specifically for the unique physiological challenges of their event, all athletes have one common characteristic: they are Homo sapiens. They share a unique genome, which is the result of evolutionary forces beyond their individual control. Although studies on the influence of different genetic polymorphisms on selected athletic events have been proven to be of limited utility, a body of evidence –from molecular biology to whole-body measures– suggests that training adaptations are enhanced when the stimulus closely resembles the activity pattern of human ancestors. Because genetic evolutionary changes occur slowly in Homo sapiens, and the traditional physical activity and dietary patterns of Homo sapiens have undergone rapid and dramatic changes in previous centuries, we propose that modern humans are physiologically better adapted to training modes and nutritional strategies similar to the ones that their hominid ancestors evolved on, rather than those supported by modern societies. Such an ancestral pattern was mainly characterized by the prevalence of daily bouts of prolonged, low-intensity, aerobic-based activities interspersed with periodic, short-duration, high-intensity bursts of activity. On some occasions, such activity patterns were undertaken with low carbohydrate availability. Specific activities that enhanced strength and power were typically performed after aerobic activities. We present scientific evidence to support the appropriateness of this model, and we propose that future studies should address this hypothesis in a multitude of different sporting activities, by assessing the genetic responses to and performance-based outcomes of different training stimuli. Such information would provide data on which sport scientists and coaches could better prepare athletes and manage their training process.
Foto: Iñigo Mujika
This is the title of my latest editorial for the September 2013 issue of the International Journal of Sports Physiology and Performance. The Q in the title refers to "quantification". In the editorial, I emphasize the importance of a precise and reliable quantifiaction of the training loads to analyze and establish causal relationships between the training performed by an athlete or a group of athletes and the resultant physiological and performance adaptations. In the blogpost about my previous editorial, "Too Young to Vote, Old Enough to Be an Olympic Champion", I highlighted the first few lines; this time I am displaying the last two paragraphs:
Rønnestad BR, Mujika I.
Scandinavian Journal of Medicine & Science in Sports. 2013 Aug 5. doi: 10.1111/sms.12104.
Here we report on the effect of combining endurance training with heavy or explosive strength training on endurance performance in endurance-trained runners and cyclists. Running economy is improved by performing combined endurance training with either heavy or explosive strength training. However, heavy strength training is recommended for improving cycling economy. Equivocal findings exist regarding the effects on power output or velocity at the lactate threshold. Concurrent endurance and heavy strength training can increase running speed and power output at VO2max (Vmax and Wmax , respectively) or time to exhaustion at Vmax and Wmax. Combining endurance training with either explosive or heavy strength training can improve running performance, while there is most compelling evidence of an additive effect on cycling performance when heavy strength training is used. It is suggested that the improved endurance performance may relate to delayed activation of less efficient type II fibers, improved neuromuscular efficiency, conversion of fast-twitch type IIX fibers into more fatigue-resistant type IIA fibers, or improved musculo-tendinous stiffness.
Given your expertise in carbohydrate and fat metabolism, what is your take on the “train low, race high” approach that suggests endurance athletes should train with low carbohydrate availability but replenish their glycogen stores for competition? Should they plan this type of strategy within their training and nutritional programmes or will something like this be achieved “by chance” anyway?
There is good hypothetical and research support for the idea that training with low glycogen stores increases the “strength” of the exercise stimulus —in other words the signalling response to a given exercise load is increased when it is done with low glycogen concentrations, producing a greater increase in the synthesis of many of the proteins associated with adaptation to exercise. We can measure greater increases in markers of the signalling, transcription and translation processes of protein synthesis, as well as an increased abundance of the proteins —especially, enzymes and transporter proteins that are involved in fat and carbohydrate metabolism in the muscle. This has been dubbed “training smarter” —or an attempt to get more “bang” for your training “buck”. Another model of “train low” is to do your workout in an overnight fasted state and without the intake of carbohydrate during the session.
