Comparative Effects of Repeated Sprint Training and Small-Sided Games on Cardiopulmonary Threshold Responses in Football Players: A Randomized Trial

Football is a game of constant motion, a sport where players cover long distances at a slow jog only to explode into sudden, frantic sprints, change direction sharply, and repeat the cycle dozens of times in a single match. To survive this physical demand, players must build a specific kind of engine: one that can deliver oxygen efficiently to working muscles while also handling the buildup of waste products that cause fatigue. For decades, coaches have relied on two main tools to build this engine. One is the small-sided game, a version of football played on a smaller field with fewer players, which forces athletes to run, pass, and think under pressure. The other is repeated sprint training, where players perform short, all-out sprints followed by brief rests, designed to push the body to its absolute limit. While both methods are widely used, a lingering question has remained: do these two approaches build the body in the same way, or does one create a stronger physiological foundation than the other?

A team of researchers at Istanbul Gelişim University set out to answer this question by putting these two training styles to a direct test. They gathered twenty-four male university football players and divided them into three groups. One group spent eight weeks performing the small-sided games, another group focused exclusively on the repeated sprint drills, and a third group continued with their normal team training without any extra specific work. Before and after this eight-week period, every player underwent a rigorous physical test on a treadmill. They ran until they could no longer continue, while scientists measured exactly how much oxygen they breathed in, how their heart rate responded, and how their lungs handled the carbon dioxide produced by their muscles. The goal was to see if the specific type of extra training changed the players' physical limits or if the improvements came simply from the act of training itself.

The results offered a clear, if somewhat surprising, picture of how the body adapts. After eight weeks, every single group of players, including those who did no extra training, became better at running for longer periods. The time it took for each player to reach total exhaustion increased significantly, regardless of whether they had been doing the small-sided games or the sprint drills. This suggests that the general routine of football practice, combined with the specific extra work, was enough to boost endurance across the board. However, when the researchers looked to see if one training method was superior to the other, the answer was a definitive no. There was no statistical evidence that the sprint drills produced better results than the small-sided games, nor did either group outperform the players who simply stuck to their regular schedule. The improvements were shared equally among all three groups.

Perhaps the most revealing finding concerned the players' maximum oxygen uptake, a standard measure of aerobic fitness often used to judge an athlete's potential. The study found that this number did not change significantly for any group, even though their ability to keep running for longer improved. This disconnect suggests that becoming better at enduring fatigue does not always require the body to increase its maximum capacity to process oxygen. Instead, the players likely became more efficient at using the oxygen they already had, or they improved their ability to tolerate the chemical changes that occur in muscles during hard work. The researchers also looked at specific points where the body switches from using oxygen to relying on other energy sources, as well as how well the body buffers the acid that builds up during intense effort. None of these specific physiological markers showed a clear advantage for either training style, and they remained largely unchanged from the start of the study to the end.

The study concludes that for university-level football players, the choice between small-sided games and repeated sprint drills may matter less than previously thought when the goal is simply to improve endurance. Both methods, and even the standard training routine, led to the same practical outcome: players could run longer before tiring. The research indicates that the body's ability to sustain effort can improve through various pathways, not just by increasing the size of the engine. For coaches and players, this means that the decision to use one training method over the other can be based on tactical needs, player enjoyment, or schedule constraints, rather than a fear that one approach will leave the athlete physically weaker than the other. The body is resilient, and in this case, it responded to the challenge of training by becoming more durable, no matter which specific path was taken to get there.