<TouchableOpacity onPress={this._onPressButtonMassa}>
  <View style={[styles.button, this.props.hipertrofia === 'sim' ?
  { backgroundColor: 'black' } : { backgroundColor: 'white' }]}>
     <Icon name="bicycle" size={50} color="#FAFAFA" />
     <Text style={styles.buttonText}>Quero ganhar massa</Text>
  </View>
</TouchableOpacity>

_onPressButtonMassa = () => {
    this.setState({ hipertrofia: 'sim' });
    this.setState({ perdapeso: 'nao' });
  };