For an affordable workout that is low impact on your joints but high impact by results, check out the Confidence CF-100 Air Resistance exercise bike.
Extremely good value. However, three criticisms: 1) visibility of lcd screen is poor due to the angle it is viewed from. If screen was horizontal legibility would be acceptable. Also, the 'tablet' stand as sited means that use of a tablet completely blocks the screen. Suggest 'stand' be fitted so tablet projects above screen. 2) impossible to not strike the seat pull out pin with your foot-heel, suggest it be fitted to the rear of the seat post. 3) The line drawing gives the impression that there are footrests for 'arms only' operation.