Tennis Play Intensity Distribution and Relation with Aerobic Fitness in Competitive Players

Abstract

The aims of this study were (i) to describe the relative intensity of simulated tennis play based on the cumulative time spent in three metabolic intensity zones, and (ii) to determine the relationships between this play intensity distribution and the aerobic fitness of a group of competitive players. 20 male players of advanced to elite level (ITN) performed an incremental on-court specific endurance tennis test to exhaustion to determine maximal oxygen uptake (VO2max) and the first and second ventilatory thresholds (VT1, VT2). Ventilatory and gas exchange parameters were monitored using a telemetric portable gas analyser (K4 b2, Cosmed, Rome, Italy). Two weeks later the participants played a simulated tennis set against an opponent of similar level. Intensity zones (1: low, 2: moderate, and 3: high) were delimited by the individual VO2 values corresponding to VT1 and VT2, and expressed as percentage of maximum VO2 and heart rate. When expressed relative to VO2max, percentage of playing time in zone 1 (77 ± 25%) was significantly higher (p < 0.001) than in zone 2 (20 ± 21%) and zone 3 (3 ± 5%). Moderate to high positive correlations were found between VT1, VT2 and VO2max, and the percentage of playing time spent in zone 1 (r = 0.68-0.75), as well as low to high inverse correlations between the metabolic variables and the percentage of time spent in zone 2 and 3 (r = -0.49-0.75). Players with better aerobic fitness play at relatively lower intensities. We conclude that players spent more than 75% of the time in their low-intensity zone, with less than 25% of the time spent at moderate to high intensities. Aerobic fitness appears to determine the metabolic intensity that players can sustain throughout the game.

Fig 1. Schematic setting for the specific endurance field test [15].

Fig 2. Heart rate (A) and oxygen uptake (B) intensity profiles during one set.

Data from a representative subject expressed as percentage of maximum (%HR_max and %$\dot{\mathrm{V}}$O_2max, respectively). Three intensity zones are delimited by the first and second ventilatory thresholds, expressed as (A) heart rate (HRVT₁, HRVT₂), and (B) $\dot{\mathrm{V}}$O₂ (VT₁, VT₂) are illustrated (light to dark grey background). The dashed vertical lines represent the 6 rest periods corresponding to game end changes.

Fig 3. Comparison of playing time (%) spent in the three differentiated intensity zones.

Intensity zones defined by the VTs zones method (below VT₁ (Zone 1), between VT₁ and VT₂) (Zone 2), and over VT₂ (Zone 3)) and defined by the HR zones method (below 70% HR_max (Zone 1), between 70 and 85% HR_max (Zone 2), and over 85% HR_max (Zone 3)). Mean ± SD values and standard deviations. **p < 0.001 for VTs zone 1 vs both VTs zones 2 and 3; *p < 0.05 for VTs zone 2 vs VTs zone 3. $ p < 0.001 for HR zone 3 vs both HR zones 1 and 2. # p < 0.001 for HR vs VTs zones 1 and 2.