Many high school, amateur and even some professional organizations do not or cannot enforce adherence to an off-season training program. As coaches, we know that what the athletes do during this down time can make or break the upcoming season. Having out-of-shape athletes report to pre-season training can impact how training camp practices are structured and progressed. Unfit players are at risk of overreaching if practice intensity is too high. In addition, more time will need to be spent on conditioning which takes away from time spent on developing technical and tactical abilities. For team sports like soccer and rugby, a high level of aerobic fitness is crucial for competition. At the very least, we want our athletes to maintain their fitness levels over the break. Therefore, it would be helpful to know what the minimum amount of training required to do this is.
A group of Norwegian researchers recently investigated this issue in a group of 17 semi-professional male soccer players. The athletes were split into two groups. Group 1 performed one session of high-intensity interval training per week while Group 2 performed one session of high-intensity interval training every other week. These sessions took place over the 6 week off-season period. VO2max and Beep Test results were acquired before and after the 6 week off-season. The high-intensity interval sessions consisted of 5 bouts of 4 minutes at 87-97% of peak heart rate. Each workout was performed on a treadmill while heart rate was recorded on a polar watch with chest-strap transmitter. After post-testing, VO2 max values were unchanged in both groups. However, distance covered during the beep test was reduced in both groups.
VO2 max values have been associated with several important performance metrics including; playing time, distance covered during a game, high-intensity bouts during a game and ball contacts. In our previous blog, we discussed how higher levels of fitness are also beneficial for recovery following competition in rugby players. Though interval training once every other week sufficiently maintained VO2max, the decrements in distance covered during the beep test is a bit concerning. The beep test is much more specific to field sports compared to incremental treadmill running as it involved frequent changes of direction. Therefore, it is unlikely that training with such a low frequency of once per week will adequately maintain field-specific fitness. It is likely that an additional day of conditioning throughout the off-season would be required to maintain shuttle test performance, though that is only speculation. Perhaps the interval sessions are better performed on a field and involve changes of direction.
Slettaløkken, G., & Rønnestad, B. R. (2014). High intensity interval training every second week maintains VO2max in soccer players during off-season. Journal of Strength and Conditioning Research. Ahead of print.