This retrospective cross-sectional study aimed to explore interactions between signs of periodontal inflammation and systemic parameters in athletes. Members of German squads with available data on sports medical and oral examination were included. Groups were divided by gingival inflammation (median of papillary bleeding index, PBI ≥ median) and signs of periodontitis (Periodontal Screening Index, PSI ≥ 3). Age, gender, anthropometry, blood parameters, echocardiography, sports performance on ergometer, and maximal aerobic capacity (VO2max) were evaluated. Eighty-five athletes (f = 51%, 20.6 ± 3.5 years) were included (PBI < 0.42: 45%; PSI ≥ 3: 38%). Most associations were not statistically significant. Significant group differences were found for body fat percentage and body mass index. All blood parameters were in reference ranges. Minor differences in hematocrit, hemoglobin, basophils, erythrocyte sedimentation rates, urea, and HDL cholesterol were found for PBI, in uric acid for PSI. Echocardiographic parameters (n = 40) did not show any associations. Athletes with PSI ≥ 3 had lower VO2max values (55.9 ± 6.7 mL/min/kg vs. 59.3 ± 7.0 mL/min/kg; p = 0.03). In exercise tests (n = 30), athletes with PBI < 0.42 achieved higher relative maximal load on the cycling ergometer (5.0 ± 0.5 W/kg vs. 4.4 ± 0.3 W/kg; p = 0.03). Despite the limitations of this study, potential associations between signs of periodontal inflammation and body composition, blood parameters, and performance were identified. Further studies on the systemic impact of oral inflammation in athletes, especially regarding performance, are necessary.