Workload: the subtle harmony between preparation and performance

In com­pet­i­tions, all that seems to mat­ter is the end res­ult: the per­form­ance in front of an audi­ence. But achiev­ing this res­ult requires pre­par­a­tion. More and more research is being car­ried out to gain a bet­ter under­stand­ing of athlete’s bod­ies and the pre­par­a­tion pro­cesses involved. Today, in the world of top-level sport, every move­ment is scru­tin­ised and every vic­tory is the res­ult of hard work and metic­u­lous preparation.

This has giv­en rise to the concept of work­load. “Over the last few years, there has been an expo­nen­tial increase in the num­ber of sci­entif­ic pub­lic­a­tions on this concept,” explains Jacques Pri­oux, uni­ver­sity pro­fess­or at École Nor­male Supérieure in Rennes. This is where the real battle lies, in the metic­u­lous man­age­ment of work­load; a del­ic­ate bal­ance to be struck between improv­ing sport­ing per­form­ance and pre­serving the athlete’s phys­ic­al integrity. 

“There are two types of work­loads: extern­al and intern­al,’ he explains. Over­all, the extern­al work­load is most often quan­ti­fied using sensors (GPS, LPS, etc.). It cor­res­ponds to the object­ive meas­ure­ment of the work done by the ath­lete dur­ing train­ing or com­pet­i­tion. The intern­al work­load cor­res­ponds to the body’s indi­vidu­al response to the demands imposed by the extern­al load. It can, for example, be quan­ti­fied using dif­fer­ent physiolo­gic­al and/or bio­lo­gic­al para­met­ers.” To ensure that the ath­lete is in the best pos­sible phys­ic­al con­di­tion, it is import­ant to study the rela­tion­ship between the extern­al work­load and the work­load spe­cif­ic to the ath­lete, the intern­al workload.

To observe and under­stand extern­al work­load, research­ers need to ana­lyse the ath­letes’ activ­ity dur­ing train­ing and com­pet­i­tion. “Tech­no­logy plays a very import­ant role,” admits the pro­fess­or. It is through tech­no­logy, and all the tools it offers us, that we can carry out mon­it­or­ing.” Vari­ous sensors, such as the GPS (glob­al pos­i­tion­ing sys­tem) for out­door sports (foot­ball, rugby, etc.) and the LPS (loc­al pos­i­tion­ing sys­tem) for indoor sports (hand­ball, vol­ley­ball, etc.), enable extremely pre­cise ana­lys­is of the ath­letes’ activ­ity. How far have they run? At what speed? How many accel­er­a­tions? Decel­er­a­tions? And so on. “The closer we get to the top level, the more cru­cial this inform­a­tion becomes,” he insists. “I am cur­rently super­vising a thes­is in which we’re work­ing on data from play­ers from Brest-Bretagne Hand­ball, i.e. the highest level in women’s hand­ball in Europe. They are all equipped with iner­tial units (anoth­er avail­able sensor) dur­ing training.”

In this way, it is pos­sible to pre­cisely ana­lyse the work car­ried out by an ath­lete dur­ing train­ing. This makes for much more optim­al pro­gram­ming. “It would be just as valu­able to obtain the same data in com­pet­i­tion con­di­tions,” admits Jacques Pri­oux. “How­ever, the cost of equip­ping sta­di­ums, gym­nas­i­ums and play­ers with these tech­no­lo­gies is very high.” This data, although import­ant, remains worth­less unless it is con­sidered in rela­tion to the impact of this Work­load on the ath­lete in ques­tion. “Work­load is only of interest if we study its rela­tion­ship with per­form­ance, but also with poten­tial injur­ies,” he insists.

It’s a well-estab­lished fact that every single body is dif­fer­ent. The same work­load may not feel the same to every­one. And each body will require dif­fer­ent pre­par­a­tion to optim­ise per­form­ance while lim­it­ing injur­ies. That’s why ana­lys­ing intern­al work­load is so import­ant, and there are many tools avail­able to research­ers to enable this to be quan­ti­fied. “At the end of a group hand­ball train­ing ses­sion, for example, we ask the play­ers to assess the level of dif­fi­culty of the ses­sion on a scale of 1 to 10,” explains the pro­fess­or. “If one play­er marks the ses­sion at 5, while anoth­er marks it at 10, we already have an import­ant point of com­par­is­on: the state of fit­ness of the two play­ers is prob­ably not the same.”

In this example, for an extern­al work­load con­sidered to be sim­il­ar, the feel­ing dif­fers between the two play­ers. This data can then be coupled with oth­er physiolo­gic­al data, such as oxy­gen con­sump­tion, heart rate or lact­ic acid con­cen­tra­tion, to object­iv­ise the effort made dur­ing training. 

In this con­text, the dose cor­res­ponds to the work­load and the response cor­res­ponds to per­form­ance or injury. The­or­et­ic­ally, if the work­load pro­posed is too low, the athlete’s level of fit­ness will prob­ably be lower than that obtained with a high­er work­load. How­ever, too high a work­load can have neg­at­ive effects on the athlete’s body, in terms of fatigue for example. The dif­fi­culty there­fore lies in identi­fy­ing and then using the right work­load. “If the work­load pro­posed dur­ing train­ing is too high, the fatigue level incurred will also be high,” explains Jacques Pri­oux. “The risk is that you won’t improve your ini­tial level of per­form­ance and you’ll end up with an injury. If the work­load pro­posed dur­ing train­ing has been cor­rectly adap­ted, the fatigue level will allow optim­al recov­ery, favour­ing an improve­ment in your ini­tial level of per­form­ance and redu­cing the risk of injury.” 

This dose-response rela­tion­ship is the sub­ject of a great deal of sci­entif­ic research, par­tic­u­larly using arti­fi­cial intel­li­gence. The aim of this sci­entif­ic work is to mod­el this dose-response rela­tion­ship and provide coaches with tools to help them plan and indi­vidu­al­ise the train­ing they offer their ath­letes. “There is still a great deal of pro­gress to be made in this area, but the goal looks increas­ingly achiev­able,” con­cludes the professor.

Pablo Andres