public async Task <IActionResult> PostActivationToExercise(string exerciseId, [FromBody] PostActivationDto activationDto)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState.Values));
            }

            var postedActivation = await _exercisesService.CreateActivation(exerciseId, activationDto.ToActivation());

            if (postedActivation == null)
            {
                return(NotFound());
            }

            return(StatusCode(201, postedActivation));
        }