Head to toe.

Each type of program has it's own pros and cons so getting straight in your mind what each one has to offer, will make the decision of which program is right for you quite clear. Whole body training's (WBT) effectiveness in promoting the full activation of all major muscle groups in one session has produced great results for many. The following are the top ten benefits to using full body workouts.

Lower Time Commitment -
The first benefit to using full body workout programs is that there is a much lower time requirement to perform them. If you're someone who has something on Monday through Sunday, it can be hard to fit in a four-day-a-week gym program. Since full body workouts can be performed over the course of just two or three days a week, this allows more time for other obligations in your life.
Allows for commitment to additional sports/activities -
Since full body workouts only call for you to be in the gym two to three times a week as already mentioned, this also frees more time for other activities. If you're currently also doing cardio training or simply enjoy other types of fitness, using a full body approach will give you four or five days of the week in which you can complete those activities. Note that you will still have to be mindful of your recovery rates because exercise is still exercise and is stressful on the body, but at least you won't be forced into doing double-day sessions as you would if you were on a higher frequency lifting schedule.
More Testosterone means more muscle -
When it comes to really putting on lean muscle mass, the amount of testosterone you have flowing through your body is really going to make a significant difference. The higher the levels of testosterone you have in your body, the faster you're going to be able to build muscle-mass tissue. When it comes to influencing testosterone release through your resistance training workouts, exercises that utilize full body movements and work as many muscle fibres as possible are going to release the greatest amount of testosterone.
Ideal for home-workouts - If you're someone who is doing their workouts at home, full body workouts make for a really good option. Often equipment choices will be limited when doing home workouts, so full body workout fit nicely since you will mostly be doing high-rep body-weight programs.
Ideal for fat loss -
Because WBT sessions allow for plenty of time between workouts (up to 2 days depending on how often each muscle groups is worked weekly) muscle growth can be maximized which, in turn, may stimulate the rate at which we burn fat calories at rest. Furthermore, by training all groupings in the same session we can directly burn more calories and place greater metabolic demands on our body, both of which promote increased fat loss.

I hope this was helpful and insightful into the benefits of taking on full body workouts. If you are a busy bee looking to get lean I would most definitely advise you start with a whole body 3 day program, with a fourth day of HIIT or yoga. Worked a treat for me! MP x