The main purpose was to investigate if long lasting cross-country (c-c) test procedures could predict performance time in ‘Vasaloppet’ and secondly the effect of a 16 weeks training period on a 90 min double poling performance test. 24 moderate trained c-c skiers participated in the study and completed Vasaloppet. All skiers carried out pre and post training tests in a 90 minutes ski-ergometer double poling test and a 120 minutes rollerski field test on a closed paved circuit. 19 skiers provided detailed training logs that could sufficiently establish their training preparation for Vasaloppet. Racing time in Vasaloppet correlated negatively with average work output (W/kg) at the pre ski-ergometer test (Figure 3A) (n = 24; r = -0.79; P < 0.001), i.e. c-c ski performance was positively associated with ergometer performance. Likewise, a similar correlation was obtained after the 16 week training period between average post-test work output in the ski-ergometer and performance in Vasaloppet (n = 24; r = -0.76; P < 0.001). The distance improved significantly from 18.0 ± 0.6 to 19.2 ± 0.7 km/h from pre to post in the ski-ergometer tests. Pre-field-test time performance on rollerskies as measured by average lap time for the 3 km circuit also correlated significantly to performance in Vasaloppet (n = 23; r = 0.78; P < 0.001). In addition, the rollerski post-field-test also showed good agreement with Vasaloppet performance, but a number of individual cancellations appeared and performance time was only measured in 11 skiers. (r = 0.82; P < 0.001). There was no change in body weight, BMI and lean arm mass but borderline increase in lean leg mass (P < 0.067), a significant increase in trunk and total lean body mass (P < 0.05) and a reduction of total body fat percentage (P < 0.05). Long lasting ski-ergometer and Rollerski field tests correlate strongly with performance in Vasaloppet and therefore might be useful test tools for recreational skiers who wish to participate in long lasting c-c competitions. Keywords: Cross-country ski training, Upper body, Exercise intensity, Field test, Body composition blood lactate