The resistance exercise trainer includes an adjustable strap wearable by a user, a leash attached to the strap at a first end and a bag attached to a second end of the leash and configured for removable reception of at least one weight. When wearing the strap and pulling the bag and the weight with the leash, the weighted bag impedes user movement thereby providing resistance exercise training. As part of the resistance exercise training, the leash may be disconnected from the strap and used individually as a jump rope and the weight may be removed from the bag and used individually in strength training exercises. Together, the strap, the leash, the bag and the weight may be used in a speed training triangle.