Problem with RecyclerView

private RecyclerView recyclerView;
private TreinoAdapter mAdapter;
private List<Treino> treinos;
private Long idCliente;
private String escolhaSelect;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_principal);

    recyclerView = (RecyclerView) findViewById(R.id.recycle);

}

/***
 * Adiciona o menu setting
 * @param menu
 * @return
 */
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item){

    String tipoEscolhido = (String) item.getTitle();

    if( tipoEscolhido.equalsIgnoreCase("Realizar") )
        this.escolhaSelect = "AR";
    else if( tipoEscolhido.equalsIgnoreCase("Realizado") )
        this.escolhaSelect = "S";
    else
        this.escolhaSelect = "N";

    this.idCliente = ((long) 1);

    retornaTreinos();

    return true;
}

/**
 * Método que abastece o RecycleView após a escolha do Item
 * */
public void abasteceRecyclerView(){

    mAdapter = new TreinoAdapter(treinos, this);

    RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getApplicationContext());
    recyclerView.setLayoutManager(mLayoutManager);
    recyclerView.setItemAnimator(new DefaultItemAnimator());
    recyclerView.setAdapter(mAdapter);

    recyclerView.addOnItemTouchListener(new RecycleTouchListener(
            getApplicationContext(),
            recyclerView,
            new RecycleTouchListener.ClickListener() {

                @Override
                public void onClick(View view, int position) {

                    Treino treino = treinos.get(position);

                    Intent intent = new Intent(PrincipalActivity.this, DetalheActivity.class);

                    Bundle bundle = new Bundle();

                    String tipoTreino = "";
                    String terreno = "";

                    if(treino.getTipo().equalsIgnoreCase("T")){

                        tipoTreino = "Bike";

                        if(treino.getTerreno().equalsIgnoreCase("T"))
                            bundle.putString("terreno", "Terra");
                        else
                            bundle.putString("terreno", "Alsfalto");

                    }
                    else if(treino.getTipo().equalsIgnoreCase("M"))
                        tipoTreino = "Musculação";
                    else
                        tipoTreino = "Descanso";


                    bundle.putString("data", treino.getDataTreino());
                    bundle.putString("tipoTreino", tipoTreino);
                    bundle.putString("descricao", treino.getDescricao());

                    intent.putExtras(bundle);
                    startActivity(intent);

                    /*Toast.makeText(getApplicationContext(), "Exibindo Detalhe",//treino.getDescricao()
                            Toast.LENGTH_LONG).show();*/


public class TreinoAdapter extends RecyclerView.Adapter {

    private List<Treino> treinos;
    private Context context;

    public TreinoAdapter(List<Treino> treinos, Context context){

        this.treinos = treinos;
        this.context = context;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);

        TreinoViewHolder treinoViewHolder = new TreinoViewHolder(view);
        return treinoViewHolder;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

        TreinoViewHolder treinoViewHolder = (TreinoViewHolder) holder;

        treinoViewHolder.dataTreino.setText(treinos.get(position).getDataTreino());
        treinoViewHolder.descricao.setText(treinos.get(position).getDescricao());

    }

    @Override
    public int getItemCount() {
        return this.treinos.size();
    }

    public class MyViewHolder extends RecyclerView.ViewHolder{

        TextView dataTreino;
        TextView descricao;

        public MyViewHolder(View itemView) {
            super(itemView);
            dataTreino = (TextView) itemView.findViewById(R.id.diaTreino);
            descricao = (TextView) itemView.findViewById(R.id.descricao);
        }
    }
}

The Activity that receives the Recycler

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_principal"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="PrincipalActivity">

    <android.support.v7.widget.RecyclerView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/recycle"
        android:scrollbars="vertical"/>

</RelativeLayout>