OK, so I know I keep going on about it, but if you are trying to get fitter in the new year and be slim, then you MUST do some resistance or strength training. Not only will this make you functionally stronger and less likely to suffer from injuries (including bad backs!) but your new lean muscle mass (from all the resistance training of course) will push your metabolic rate up and mean that you will burn more energy all the time. This is really effective if you are also eating well and undercutting calories a little. For more on the resistance training see our fact sheets on the knowledge page. Tune in tomorrow for more insider personal trainer information..