TABLE 4.

Percentage of total match time spent in each intensity zone expressed as percentage of players’ maximal heart rate during singles or doubles beach tennis session stratified by the competition level of the participants.

Variables	Level 1: Advanced (n = 11)	Level 2: Intermediate (n = 11)	Δ	p-Value
Heart rate
Time <60%HRmax (%)
Singles	2.7 ± 0.7 (1.2–4.1)*	3.4 ± 1.4 (0.6–6.1)	0.7 ± 1.6 (−3.8 to 2.4)	0.658
Doubles	8.9 ± 1.9 (5.1–12.8)	6.4 ± 3.3 (−0.1–12.9)	2.5 ± 3.8 (−5.0–10.0)	0.514
Time 61–70%HRmax (%)
Singles	8.1 ± 1.2 (5.6–10.5)*	8.2 ± 1.7 (4.8–11.6)	0.1 ± 2.1 (−4.3 to 4.1)	0.963
Doubles	26.8 ± 5.7 (15.7–38.0)	13.6 ± 4.1 (5.7–21.4)	13.2 ± 6.9 (−26.9 to 0.4)	0.057
Time 71–80%HRmax (%)
Singles	13.6 ± 1.5 (10.7–16.5)*	18.7 ± 3.1 (12.6–24.9)*	5.1 ± 3.5 (−11.9 to 1.7)	0.138
Doubles	35.7 ± 3.1 (29.5–41.9)	25.0 ± 4.5 (16.2–33.8)	10.7 ± 5.5 (−21.5 to 0.8)	0.052
Time 81–90%HRmax (%)
Singles	31.8 ± 3.3 (25.3–38.3)	32.0 ± 3.1 (25.9–38.1)	0.2 ± 4.6 (−9.1 to 8.8)	0.971
Doubles	21.9 ± 5.4 (11.4–32.6)	33.1 ± 4.9 (23.4–42.9)	11.2 ± 7.3 (−25.6 to 3.4)	0.129
Time 91–100%HRmax (%)
Singles	44.0 ± 5.7 (32.8–55.2)*	38.0 ± 5.8 (26.6–49.4)*	6.0 ± 8.1 (−9.9–21.9)	0.462
Doubles	6.6 ± 3.6 (−0.4–13.6)	21.8 ± 6.5 (8.9–34.6)	15.2 ± 7.5 (−29.8 to −0.6)	0.041

Values are Means ± standard error (95% Confidence Interval); HRmax = maximal heart rate; *Singles is different from Doubles (p < 0.05); p-value is comparing the competition levels separately in the session (level 1 vs. level 2). Bold p-values indicate significant results (p < 0.05).