Purpose:
The study aim was to analyse 1 × 1 small-sided games (SSGs) with and without floating players, in different pitch sizes.

Methods:
Ten U-12 soccer players were divided into 2 groups. Group 1 (n = 4) performed 1 × 1 SSG and group 2 (n = 6) performed 1 × 1 + 1 SSG. Field sizes of 5 × 10 m (SSG1), 10 × 15 m (SSG2), and 15 × 20 m (SSG3) were used, all with small goals. The studied variables were heart rate (HR), total distance, explosive distance (> 12 km/h), accelerations, decelerations, maximum sprint, player load (PL) intensity and volume. The data were collected through WIMU PROTM and analysed with IBM SPSS Statistics. Descriptive analyses and comparisons between the effects of internal and external PL and SSG were performed with the Mann-Whitney U test.

Results:
Increasing the pitch size in 1 × 1 and 1 × 1 + 1 SSGs led to raised total distance, maximum sprint, and PL. In 1 × 1 and 1 × 1 + 1 SSGs, the time practice was predominantly associated with HR_max intervals above 90%. Statistically significant differences were observed between 1 × 1 and 1 × 1 + 1 SSGs in explosive distance (SSG2: 46.40 ± 5.07 / 28.99 ± 4.93, p = 0.02, ES(r) = 0.82), PL intensity (SSG2: 2.03 ± 0.11 / 1.78 ± 0.12, p = 0.02, ES(r) = 0.82), HR_max (SSG1: 189.50 ± 1.91 / 199.50 ± 2.38, p = 0.01, ES(r) = 0.82), and HR_mean (SSG1: 174.50 ± 3.31 / 181.75 ± 2.21, p = 0.01, ES(r) = 0.82). Floating players’ physical and physiological demands were lower compared with the other athletes.

Conclusions:
The pitch size influences the physiological and physical response of young soccer players in SSGs. The demand of 1 × 1 SSG is higher compared with 1 × 1 + 1. Floating player participation could result in a fruitful strategy to adjust the training intensity of specific soccer players.